CN114844520B

CN114844520B - Radio frequency system and SAR value regulation and control method

Info

Publication number: CN114844520B
Application number: CN202210405820.3A
Authority: CN
Inventors: 彭博
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2022-04-18
Filing date: 2022-04-18
Publication date: 2024-08-09
Anticipated expiration: 2042-04-18
Also published as: CN114844520A

Abstract

A radio frequency system and SAR value regulation and control method are provided. The radio frequency system comprises: the radio frequency transceiver is provided with a detection end; the first coupler on the first radio frequency channel is used for sampling radio frequency signals on the first coupler so as to output first coupling signals; the second coupler on the second radio frequency path is used for sampling radio frequency signals on the second coupler so as to output second coupling signals; the power detector on the detection path is used for carrying out power detection on the first coupling signal and the second coupling signal, and outputting a detection result through the detection end, wherein the detection result is used for controlling SAR values when the first antenna and/or the second antenna work. In the embodiment of the application, when the SAR value of the antenna is detected, the plurality of radio frequency channels share one detection end of the radio frequency transceiver, so that the power detection of more paths of radio frequency signals can be supported by using a limited number of detection ends. In addition, the plurality of radio frequency paths share one detection end of the radio frequency transceiver, so that the hardware cost is reduced.

Description

Radio frequency system and SAR value regulation and control method

Technical Field

The embodiment of the application relates to the technical field of wireless communication, in particular to a radio frequency system and an SAR value regulation method.

Background

In recent years, wireless communication technology has been increasingly used, and wireless communication devices have also been increasingly popular. Radio frequency signals emitted by wireless communication devices can have a radiation effect on the human body. The radiation impact of radio frequency signals on the human body is typically measured by specific absorption rate (specific absorption rate, SAR) values, also called specific absorption rate.

Some wireless communication devices have multiple radio frequency paths. The plurality of radio frequency channels may simultaneously transmit radio frequency signals through the plurality of antennas. For example, for a wireless communication device supporting uplink multiple-input multiple-output (uplink multi input multi output, UL MIMO), multiple antennas may transmit uplink signals simultaneously during uplink transmission.

In order to accurately measure SAR values of the above wireless communication devices, power detection is generally required for multiple radio frequency signals. However, the number of detection terminals of the radio frequency system is limited, and power detection of multiple radio frequency signals may not be supported.

Disclosure of Invention

The embodiment of the application provides a radio frequency system and an SAR value regulation method, which are used for supporting power detection of multipath radio frequency signals.

In a first aspect, there is provided a radio frequency system comprising: the radio frequency transceiver is provided with a first transmitting end, a second transmitting end and a detecting end; one end of the first radio frequency channel is connected with the first transmitting end, and the other end of the first radio frequency channel is connected with a first antenna, wherein a first coupler is arranged on the first radio frequency channel and is used for sampling radio frequency signals in the first radio frequency channel so as to output first coupling signals; one end of the second radio frequency path is connected with the second transmitting end, and the other end of the second radio frequency path is connected with a second antenna, wherein a second coupler is arranged on the second radio frequency path and is used for sampling radio frequency signals in the second radio frequency path so as to output second coupling signals; the detection path is connected with the detection end, a power detector is arranged on the detection path and is used for carrying out power detection on the first coupling signal and the second coupling signal, and a detection result of the power detection is output to the radio frequency transceiver through the detection end; and the radio frequency transceiver adjusts the transmitting power according to the detection result and the SAR value corresponding to the detection result so as to control the SAR value when the first antenna and/or the second antenna work.

In a second aspect, a SAR value regulation method of a radio frequency system is provided, where the radio frequency system includes: the radio frequency transceiver is provided with a first transmitting end, a second transmitting end and a detecting end; a first radio frequency path, one end of the first radio frequency path is connected with the first transmitting end, the other end of the first radio frequency path is connected with a first antenna, the first coupler is used for sampling radio frequency signals in the first radio frequency channel so as to output first coupling signals; the second radio frequency channel, one end of the second radio frequency channel is connected with the second transmitting end, the other end of the second radio frequency channel is connected with the second antenna, wherein a second coupler is arranged on the second radio frequency channel and is used for sampling radio frequency signals in the second radio frequency channel so as to output second coupling signals; the detection path is connected with the detection end, a power detector is arranged on the detection path and is used for carrying out power detection on the first coupling signal and the second coupling signal, and a detection result of the power detection is output to the radio frequency transceiver through the detection end; the method comprises the following steps: acquiring an SAR value of the electronic equipment according to the detection result; and adjusting the transmitting power of the first antenna and/or the second antenna according to the SAR value of the electronic equipment.

In a third aspect, there is provided a wireless communication device comprising: the radio frequency system of the first aspect; and the control module is connected with the radio frequency system and used for controlling SAR values when the first antenna and/or the second antenna work according to the detection result output by the radio frequency system.

In the embodiment of the application, the plurality of radio frequency channels share one detection end of the radio frequency transceiver, so that the power detection of more paths of radio frequency signals can be supported by using a limited number of detection ends. In addition, the plurality of radio frequency paths share one detection end of the radio frequency transceiver, so that the hardware cost is reduced.

Drawings

Fig. 1 is a schematic diagram of a radio frequency system and a complete machine antenna according to the related art.

Fig. 2 is a schematic diagram of a directional coupler provided by the related art.

Fig. 3 is a schematic diagram of a bi-directional coupler provided by the related art.

Fig. 4 is a schematic diagram of a wireless communication apparatus provided in the related art.

Fig. 5 is a schematic diagram of measuring reflected power of multiple antennas according to the related art.

Fig. 6 is a schematic diagram of a radio frequency system according to an embodiment of the present application.

Fig. 7 is a schematic diagram of another radio frequency system according to an embodiment of the present application.

Fig. 8 is a schematic diagram of a detection path provided by the related art.

Fig. 9 is a schematic diagram of a detection path according to an embodiment of the present application.

Fig. 10 is a schematic diagram of yet another radio frequency system according to an embodiment of the present application.

Fig. 11 is a schematic diagram of a transmit power versus TA-SAR control relationship.

Fig. 12 is a schematic diagram of a TA-SAR control method.

Fig. 13 is a schematic diagram of yet another radio frequency system according to an embodiment of the present application.

Fig. 14 is a schematic diagram of a wireless communication device according to an embodiment of the present application.

Fig. 15 is a schematic flow chart of a SAR value control method according to an embodiment of the present application.

Fig. 16 is a flowchart of another SAR value control method according to an embodiment of the present application.

Fig. 17 is a flowchart of another SAR value control method according to an embodiment of the present application.

Detailed Description

The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments.

In recent years, with the development of communication technology, wireless communication devices are becoming more and more widely used, and wireless communication devices are also being updated iteratively. It should be noted that the wireless communication device according to the embodiment of the present application may be a device that provides voice and/or data connectivity to a user, and may be used to connect people, things and machines, such as a handheld device with a wireless connection function, an in-vehicle device, and so on. The wireless communication device in the embodiments of the present application may be, for example, a mobile phone (mobile phone), a tablet (Pad), a notebook, a palm, a mobile internet device (mobile INTERNET DEVICE, MID), a wearable device, a Virtual Reality (VR) device, an augmented reality (augmented reality, AR) device, a wireless terminal in industrial control (industrial control), a wireless terminal in unmanned (SELF DRIVING), a wireless terminal in teleoperation (remote medical surgery), a wireless terminal in smart grid (SMART GRID), a wireless terminal in transportation security (transportation safety), a wireless terminal in smart city (SMART CITY), a wireless terminal in smart home (smart home), or the like.

Wireless communication devices typically include a baseband system and a radio frequency system. The baseband system is used for generating a baseband signal, and the radio frequency system is used for converting the baseband signal into a radio frequency signal so as to transmit the radio frequency signal into a wireless channel through an antenna.

During the use of a wireless communication device, electromagnetic radiation is generated by radio frequency signals at any time, which can have health effects on a human body, and is generally measured by a Specific Absorption Rate (SAR) value, which is also called an electromagnetic wave absorption ratio. SAR is an internationally universal index for evaluating the influence of radio waves on the human body, belongs to safety standards, and is closely regulated by regulatory authorities in all countries/regions worldwide.

SAR is defined as the electromagnetic power absorbed or consumed by a unit mass of human tissue. The SAR value represents the effect of radiation on the human body and is the most direct test value, the SAR is specific to data of the whole body, the part and the four limbs, and the lower the SAR value is, the less radiation is absorbed. According to SAR specifications, the radio frequency energy accumulated in the head or body during wireless communication transmissions of the device must not exceed a certain safety value. The radio frequency energy may be calculated by integrating the transmit power of the wireless communication device over a determined time window. The SAR regulatory authorities in different countries and regions have slightly different SAR standards requirements, and the two currently prevailing international standards are 1.6W/kg of the federal communications commission (federal communications commission, FCC) and 2.0W/kg of the european union, respectively.

The SAR regulatory requirements for electromagnetic wave signals of different frequencies are slightly different for each region. Taking the FCC standard as an example, for radio frequency signals below 3GHz, the average SAR value over a time period of 100 seconds is required not to exceed the upper limit requirement of 1.6W/kg. It will be appreciated that the real-time SAR value may exceed 1.6W/kg in accordance with current regulations, only to ensure that the average SAR value within the time window required by the regulations (e.g. 100 seconds) is controlled within the range required by the regulations.

The SAR value is mainly dependent on the radiation power actually emitted via the antenna. The radiation power actually emitted by the antenna is strongly related to parameters such as the emission power of a radio frequency circuit, the antenna efficiency, the radiation pattern of the antenna and the like, and is in direct proportion to the conduction power (such as the incident power), and the higher the conduction power is, the higher the SAR value is.

Fig. 1 provides a schematic diagram of the radio frequency system and the overall antenna location of a wireless communication device. The device under test (device under test, DUT) in fig. 1 may refer to any of the wireless communication devices above, such as a smart phone. In connection with fig. 1, the main components of the radio frequency system of the device under test 100 and the distribution of the conducted power of the antenna with respect to SAR values will be described.

The left hand diagram of fig. 1 shows the radio frequency system of the device under test 100. The radio frequency system comprises: a radio frequency transceiver 130, a transmit path 110, a receive path 120, etc.

The radio frequency transceiver 130 has a TX port connected to the transmit path 110 and also has an RX detection port connected to the receive path 120. The radio frequency transceiver 130 may control the transmit frequency and power amplification of the signal.

The transmit path 110 may include a Power Amplifier (PA) 111, an antenna 112, and the like. The power amplifier 111 is used for adjusting the power of the amplified transmission signal, and the antenna 112 is used for transmitting and receiving the radio frequency signal.

The receive path 120 may include a low noise amplifier (low noise amplifier, LAN) 121, etc. The LNA may be used to amplify a received signal, and the post processing of the received signal is based on the amplified signal of the LNA, so that a low noise LNA is of great importance.

The right hand view of fig. 1 is a plan view of a device under test 100 (e.g., a cell phone). Referring to the right-hand view of fig. 1, the antenna is located in the upper left corner of the device under test 100.

For a given radio frequency path, and for a given state of the conducted power and antenna, the location of the hot spot of SAR (or the highest point of SAR values) is determined, the distribution of SAR is fixed (referring to the gradient map of SAR), and the SAR value (in particular the maximum SAR value) is also determined.

As shown in the right hand graph of fig. 1, the dashed circle in the upper left hand corner of the device under test 100 can be understood as an isostearic value profile. The same elliptic line passes through the same SAR value, and the farther the ellipse is from the central position of the antenna, the lower the SAR value is. It can be appreciated that the higher the transmit power of the radio frequency circuit, the higher the hotspot value of the SAR (center of the dashed elliptical circle); the lower the transmit power, the lower the hotspot value of the SAR. The requirements of the regulatory authorities are: the average SAR value of the highest point of SAR values does not exceed regulatory requirements, such as: FCC was 1.6W/Kg and CE was 2.0W/Kg.

Because the SAR value is in direct proportion to the conducted power of the antenna, the most common means for solving the SAR superscalar in the current industry is to reduce the radio frequency power, or power backoff. In the actual use process, the SAR value can be adjusted according to the radiation power of the antenna. In some implementations, the radiated power of the antenna may be detected by measuring the forward transmitted power of the antenna, or by measuring the reflected power of the antenna.

Since the antenna is the last impedance element on the radio frequency circuit, measuring the reflected power of the antenna can include the SAR variation caused by the influence of the outside on the performance of the antenna itself.

In a radio frequency transmission system of a communication device, if a mismatch occurs in the load, a portion of the incident power is reflected back to the signal source. Due to the different mismatch conditions, the same incident signal will produce reflected signals of different magnitudes, the degree of mismatch is usually quantitatively described by Return Loss (RL), also known as reflection loss. As shown in the following formula.

RL = incident power/reflected power

The return loss is the ratio of the incident power to the reflected power of the radio frequency circuit, and is a mismatch problem of input and output from the power point of view. For example, if 1mW (0 dBm) of power is input to the antenna, if 10% of it is reflected (bounces back), the return loss is 10dB. In the case of determining parameters such as element impedance, antenna efficiency, radiation pattern of the antenna, etc. of the radio frequency circuit, the return loss of the radio frequency circuit is also fixed.

There are various ways to measure the reflected power of the antenna, and it is possible to measure the power of the entire reflected signal of the antenna, and also to measure the power of the sampled signal of the reflected signal of the antenna.

The coupler is a power distribution device, and in a radio frequency transceiver system, signals can be "sampled" through the coupler. Fig. 2 is a schematic diagram of a directional coupler, as shown in fig. 2, in which the signal size of the coupling path is proportional to the size of the signal passing through the coupler, and the ratio of the coupled signal to the input signal is referred to as the coupling coefficient, which is generally fixed. More and more radio frequency systems employ couplers as a means of detecting power.

The coupler has a directional coupler and a bidirectional coupler, and as shown in fig. 3, the bidirectional coupler can perform power coupling on the input signal in the forward direction or in the reverse direction.

The adjustment of the transmit power for the radio frequency signal may be based on the reflected power of the radio frequency signal according to a fixed return loss. Since the coupling coefficient of the coupler is fixed, the adjustment for the reflected power may be based on the output power of the coupled signal of the coupling port of the coupler. The coupling signal may be a sampling signal of a transmission signal to the antenna side or a sampling signal of a reflection signal from the antenna side.

Thus, the adjustment for the transmit power may be based on the power of the coupling signal at the coupling port of the coupler. As shown in fig. 4, taking the coupling form of a directional coupler as an example, this way, the influence of the outside on the performance of the antenna itself can be included to cause the SAR variation.

While the above describes the SAR control mechanism for a single rf channel, in practical applications, multiple rf systems are very common, where some multiple rf signals have the same power level, such as UL MIMO, and some multiple rf signals have different frequencies and different power levels.

UL MIMO is a widely used technology for LTE/NR at present, which can greatly improve the uplink throughput rate, and on a hardware circuit, it has completely independent two-way transmission paths. As shown in fig. 5, the power of the UL MIMO two transmission signals is the same, and the two transmission signals increase or decrease with the same amplitude when the power is adjusted.

In a wireless communication device having a plurality of transmitting circuits, the signal power of each transmitting antenna needs to be detected, and a plurality of signal detection paths are required. For convenience of explanation, an example of measuring reflected power of a coupled signal of multiple antennas provided by the related art is described with reference to fig. 5, taking a radio frequency system of two radio frequency paths based on UL MIMO as an example.

As shown in fig. 5, the radio frequency system of the device under test 200 includes: a radio frequency transceiver 230, a first transmit path 210, a first detect path 212, a second transmit path 220, a second detect path 222, and so on.

The radio frequency transceiver 230 has ports connected to the first transmit path 210 and the second transmit path 220 and also has ports connected to the first detect path 212 and the second detect path 222. The radio frequency transceiver 230 may control the transmit frequency of the signal and the power level of the input PA.

The first transmit path 210 is used for transmitting and receiving a first signal, and includes a power amplifier, an antenna 211, etc., and may also include a duplexer, a switch, etc., which are not shown in the figure.

The first receiving detection path 212 is connected to the first transmitting path 210 through a first directional coupler 213 for power detection of the coupled signal of the first transmitting path 210. The first reception detection path 212 includes a LAN, and may also include a filter, a mixer, and the like, which are not shown in fig. 5, as can be seen in detail in fig. 8.

Currently, the detection path is generally implemented by directly demodulating and detecting the signal, i.e. the receiving path is similar to the radio frequency path in nature, and has a complete receiving link. Fig. 8 is a schematic diagram of a radio frequency system provided in the related art, mainly for illustrating the structure of the detection path, and fig. 8 only shows one radio frequency path.

As shown in fig. 8, the reception detection path 530 includes a LAN 521, a filter 522, a mixer 523, and the like. The LNA521 is connected to the coupler 512, and is configured to amplify and receive a weak coupled signal. The filter 522 is connected to the LNA521, and is mainly used to filter out in-band interference sources, such as interference signals generated in the paths of the LNA 521. The mixer 523 is located after the filter 522 and the LNA521, and processes the LNA-amplified radio frequency signal.

The second transmit path 220 is used for transmitting and receiving a second signal, and includes a power amplifier, an antenna 221, etc., and may also include a duplexer, a switch, etc., which are not shown in the figure.

The second reception detection path 222 is connected to the second transmission path 220 through a second directional coupler 223 for power detection of the coupled signal of the second transmission path 220. The second reception detection path 222 includes a LAN, and may also include a filter, a mixer, and the like, which are not shown in fig. 5.

The right hand diagram of fig. 5 is a plan view of the device under test 200 (e.g., a cell phone), where the first antenna in the upper left hand corner of the device under test 200 is representative of the location of antenna 211 and the second antenna in the lower right hand corner is representative of the location of antenna 221.

In a wireless communication device with a plurality of radio frequency circuits, a plurality of signal detection paths are required for detection of reflected power of a plurality of signals. If the number of detection ports of the radio frequency transceiver is only one or less than the number of radio frequency circuits, power detection of the reflected signals of multiple antennas cannot be achieved. As shown in fig. 5, two signal detection paths are required for the detection of two reflected power signals. If the rf transceiver only supports one independent detection port, power detection of the reflected signal from the multiple antennas cannot be achieved.

It should be noted that the above-mentioned wireless communication device with two radio frequency paths is only an example, and the embodiments of the present application may be applied to any type of scenario where signal detection paths of a plurality of radio frequency circuits are limited by detection ports.

Therefore, how to make the detection path not affected by the limitation of the detection port in the multi-radio circuit system, developing a signal power detection scheme suitable for the multi-radio circuit is a problem to be solved.

In view of the foregoing, an embodiment of the present application provides a radio frequency system, and the following details of the embodiment of the present application are described.

In some multi-antenna systems, the transmitting power of the multi-channel radio frequency channels is the same, the arrangement distance of the antennas is the same, and the SAR values corresponding to the same transmitting power of the radio frequency circuits are the same. When the two-way detection device works simultaneously, one-way detection can be independently performed, and the transmitting power of the radio frequency circuit can be combined and detected. And the transmitting power of each radio frequency path is combined and detected, and the coupling signals of the radio frequency paths are required to be combined and then connected into a detection channel.

In some implementations, a combiner may be used to combine signals from the radio frequency channels, and a power divider is a common combiner. The power divider is a device for dividing one input signal energy into two or more paths of equal or unequal energy, and can also reversely combine multiple paths of signal energy into one path of output, which is called a combiner at the moment.

Fig. 6 is a schematic diagram of a radio frequency system according to an embodiment of the present application, taking a radio frequency system based on UL MIMO and having two same transmission frequency radio frequency circuits as an example. The left diagram of fig. 6 shows a radio frequency system of the device under test 300, comprising: a radio frequency transceiver 340, a first radio frequency path 310, a second radio frequency path 320, a detection path 330, and the like.

The radio frequency transceiver 340 has a first transmitting end, a second transmitting end, and also has a detection port coupled to the detection path 330. The rf transceiver 340 is used for receiving and transmitting multiple rf signals and receiving feedback detection signals.

One end of the first rf path 310 is connected to a first transmitting end of the rf transceiver 340 and the other end is connected to the first antenna 311. A first coupler 312 is provided on the first rf path 310, the first coupler 312 being located on the inlet side of the first antenna 311. The first coupler 312 is configured to sample the radio frequency signal in the first radio frequency path 310 to output a first coupled signal.

The coupler is a radio frequency device which extracts a small part of signals from a wireless signal main channel, and the coupler belongs to a power distribution device like a power divider, except that the coupler is a non-equal power distribution device.

One end of the second rf path 320 is connected to the second transmitting end of the rf transceiver 340, the other end is connected to the second antenna 321, and a second coupler 322 is disposed on the second rf path 320, and the second coupler 322 is located at an inlet side of the second antenna 321. The second coupler 322 is configured to sample the radio frequency signal in the second radio frequency path 320 to output a second coupled signal.

An active divider 331 is provided in the detection path 330. The power divider 331 has a first input terminal, a second input terminal, and an output terminal, where the first input terminal is connected to the first coupler 312 and is configured to receive the first coupling signal; a second input terminal thereof is connected to the second coupler 322 for receiving a second coupling signal; the output terminal of the signal is connected to the power detector 332 on the detection path, and is used for outputting a combined signal of the first coupling signal and the second coupling signal to the power detector 332.

An output terminal of the detection path 330 is connected to a detection terminal of the radio frequency transceiver 340, and power information detected by the power detector 332 is input to a detection port of the radio frequency transceiver 340.

The right diagram of fig. 6 is a plan view of the device 300 under test (e.g., a mobile phone), and shows the positions of the first antenna 311 and the second antenna 321, where the distances between the two antennas are similar.

The radio frequency system can calculate the transmitting power of the antenna according to the power detection result of the coupling signal, and the relation between the transmitting power of the antenna and the SAR value is corresponding. Therefore, according to the power detection result of the coupling signal, the SAR values of the first antenna and the second antenna when working can be controlled. When the calculated SAR value is smaller than the SAR value required by the standard, not adjusting; when the calculated SAR value is close to or larger than the SAR value required by the standard, the transmitting power of the first antenna and the transmitting power of the second antenna are reduced, and then the SAR value meets the compliance requirement.

According to the embodiment of the application, the detection path is used for controlling SAR values when the radio frequency system works by carrying out combined power detection on the coupling signals of each radio frequency circuit and using the power detection result of the radio frequency circuit. The power detection of the multi-radio frequency circuit signal can be realized only by one detection path, and the use requirement of multi-path power detection is met.

In some multi-antenna radio frequency systems, the frequencies of the multi-channel radio frequency channel signals are different, the isolation between the antennas and the distance arrangement of the antennas are different, and the power levels are also different, so that the SAR corresponding to the same transmitting power of the radio frequency circuit is also different, and independent detection is needed. In some multi-antenna systems, although the transmission power of the multiple radio frequency paths is the same, the arrangement distances of the corresponding antennas are different, and the influence of the transmission power of the radio frequency paths on the SAR value is different. For example, in some MIMO dual-antenna systems, the isolation between two antennas needs to be increased, and the antenna design usually pulls the distance between the two antennas farther, which may occur when the SAR values of the two antennas are different under the same total reflected rf power. Therefore, when testing the SAR of each antenna, it is necessary to detect the reflected powers of the antennas of the two radio frequency circuits, respectively, so that it can be determined which antenna is dominant by the current SAR value. And by using a combiner, the SAR value of the radio frequency path which is the path cannot be distinguished to be out of standard.

The transmitting power of each radio frequency path is detected independently, and the coupling signals of the radio frequency paths are required to be connected to the detection channels independently. In some implementations, a switch may be employed to alternately detect the transmit power of each radio frequency path. Fig. 7 is a schematic diagram of a radio frequency system according to an embodiment of the present application. The left diagram of fig. 7 shows a radio frequency system of a device under test 400, comprising: a radio frequency transceiver 440, a first radio frequency path 410, a second radio frequency path 420, a detection path 430, and the like.

The radio frequency transceiver 440 has a first transmitting end and a second transmitting end and also has a detection port coupled to the detection path 430. The rf transceiver 440 is used for receiving and transmitting multiple rf signals and receiving feedback detection signals.

One end of the first rf path 410 is connected to a first transmitting end of the rf transceiver 440 and the other end is connected to the first antenna 411. A first coupler 412 is provided on the first rf path 410, the first coupler 412 being located on the inlet side of the first antenna 411. The first coupler 412 is configured to sample the rf signal in the first rf path 410 to output a first coupled signal.

One end of the second rf path 420 is connected to a second transmitting end of the rf transceiver 440, the other end is connected to the second antenna 421, and a second coupler 422 is disposed on the second rf path 420, and the second coupler 422 is located at an inlet side of the second antenna 421. The second coupler 422 is configured to sample the radio frequency signal in the second radio frequency path 420 to output a second coupled signal.

The detection path 430 is provided with a switch 431 and a power detector 432.

The switch 431 has a first input terminal, a second input terminal and an output terminal, wherein the first input terminal is connected to the first coupler 412 for receiving the first coupling signal; a second input terminal thereof is connected to the second coupler 422 for receiving a second coupled signal; the output of which is connected to a power detector 432 on the detection path. When the switch 431 controls the first input terminal to be conducted with the output terminal, the switch 431 outputs a first coupling signal to the power detector 432 through the output terminal thereof; when the switch 431 controls the second input terminal to be conducted with the output terminal, the switch 431 outputs a second coupling signal to the power detector 432 through the output terminal thereof.

When the switch 431 outputs the first coupling signal to the power detector 432, the power detector 432 is configured to perform power detection on the first coupling signal; when the switch 431 is switched to the second input terminal and the second coupling signal is output to the power detector 432, the power detector 432 is configured to perform power detection on the second coupling signal.

The right diagram of fig. 7 is a plan view of the device under test 400 (e.g., a mobile phone), and shows a schematic of the positions of the first antenna 411 and the second antenna 421, where the distances between the two antennas are relatively far.

The radio frequency system can calculate the transmitting power of each antenna according to the power alternative detection result of the coupling signal, and the relation between the transmitting power of each antenna and the respective SAR value is corresponding. Therefore, according to the power detection result of the coupling signal, the superposition SAR value when the first antenna and the second antenna work can be calculated. When the calculated superimposed SAR value is smaller than the SAR value required by the standard, not adjusting; when the calculated superimposed SAR value is close to or larger than the SAR value required by the standard, the transmitting power of the first antenna and the transmitting power of the second antenna can be reduced simultaneously, and the transmitting power of the dominant first antenna can be reduced, so that the SAR value meets the compliance requirement.

The scheme of alternately detecting by adopting the switch is not only suitable for the scene of the same power of MIMO, but also suitable for the scheme of the multi-channel radio frequency front end with different same frequencies such as uplink carrier aggregation (uplink carrier aggregation, UL CA) and the like.

Carrier aggregation is a technique for allocating multiple component carriers (component carrier, CC) to a user equipment to increase the bandwidth available for data communication, thereby increasing the data throughput of the equipment. The bandwidth of each component carrier may be between 1.4-20MHz, and up to 5 component carriers may be aggregated to produce a maximum aggregated bandwidth of 100MHz according to advanced long term evolution standards. In practice, most cellular service operators supporting carrier aggregation aggregate two or at most three component carriers, and it is expected that more than three component carriers may be aggregated in the future if a wider bandwidth is needed or desired.

The current common implementation method of the detection path is to directly demodulate the signal and then detect, i.e. the receiving path is similar to the radio frequency path in nature, and has a complete receiving link. Fig. 8 is a schematic diagram of a radio frequency system provided in the related art, mainly for illustrating the structure of the detection path, and fig. 8 only shows one radio frequency path. As shown in fig. 8, the radio frequency system includes: a radio frequency transceiver 540, a radio frequency path 510, a detection path 530, and the like.

The rf transceiver 540 has a transmitting end and a detecting end, and the rf transceiver 540 is used for receiving and transmitting an rf signal and receiving a feedback detection signal.

One end of the rf path 510 is connected to a transmitting end and the other end is connected to an antenna 511. A coupler 512 is disposed on the rf path 510, and the coupler 512 is located at an inlet side of the antenna 511, for sampling the rf signal in the rf path 510 to output a coupled signal.

The detection path 530 is coupled to the radio frequency path 510 through a coupler 512 for power detection of the coupled signal. The reception detection path 530 includes devices such as a LAN 521, a filter 522, and a mixer 523.

The LNA 521 is connected to the coupler 512 for amplifying and receiving weak coupled signals. In the case of amplifying weak signals, the noise of the amplifier itself may have serious interference to the signals, and the post-processing is performed based on the signals amplified by the LNA, so that the LNA with low noise is important in the detection path.

The filter 522 is connected to the LNA 521, and is mainly used for filtering out in-band interference sources, such as interference signals generated in the paths of the LNA 521, etc., to separate useful signals from noise, and improve the anti-interference performance and signal-to-noise ratio of the signals. The filter 522 is an acoustic surface filter that uses the acoustic resonance effect to perform filtering.

The mixer 523 is located after the filter 522 and the LNA 521, and processes the LNA-amplified radio frequency signal. The mixer 523 is typically composed of a nonlinear element and a frequency selective loop.

It can be seen that the detection path performs power detection after down-converting and demodulating the coupled signal. The whole receiving detection path has complex structure, and various active devices such as a filter, a mixer and the like on a link are likely to generate nonlinearity and generate additional harmonic interference, thereby affecting the accuracy of power detection.

Aiming at the problems of the detection path, the embodiment of the application provides a detection path based on a radio frequency power meter. Fig. 9 is a schematic diagram of a radio frequency system based on a detection path of a radio frequency power meter according to an embodiment of the present application. As shown in fig. 9, the radio frequency system includes: a radio frequency transceiver 640, a radio frequency path 610, a detection path 630, etc.

The radio frequency transceiver 640 has a transmitting end and a detecting port, and the radio frequency transceiver 640 is used for receiving and transmitting radio frequency signals and receiving feedback detection signals.

One end of the rf path 610 is connected to the transmitting end of the rf transceiver 640 and the other end is connected to the antenna 611. A coupler 612 is disposed on the rf path 610, and the coupler 612 is located at an inlet side of the antenna 611 and is used for sampling the rf signal in the rf path 610 to output a coupled signal.

The detection path 630 is coupled to the radio frequency path 610 through the coupler 612 for power detection of the coupled signal. The detection path 630 is provided with a radio frequency power meter 632, and the radio frequency power meter 632 is used for performing power detection on the coupling signal.

The radio frequency power meter is a high-performance high-frequency power meter designed for measuring various complex waveforms, can effectively solve the problems of power and amplitude measurement of the complex waveforms, and greatly improves the usability and reliability of the meter.

The radio frequency power meter is used for replacing the power detection path to measure the power of the signal, filtering, frequency reduction, demodulation and the like are not needed, nonlinearity generated by active nonlinear devices such as LNA, mixer and the like is removed, and interference among systems is reduced. The radio frequency power meter can directly obtain the power of the coupling signal, has higher precision and smaller error, and has simpler power detection path and reduced hardware cost.

A specific manner of detection and control of the multiple rf path system is described below with reference to fig. 10, taking an rf power meter based detection path as an example. The embodiment of fig. 10 is a multi-rf path system, such as a mobile phone, where the transmission power of two rf paths in the UL MIM system is the same, and SAR value control is implemented based on detection after combining the transmission frequencies. The SAR value can be controlled by a variety of methods, such as a conventional fixed back-off radio frequency power method, and a time average specific absorption rate (TA-SAR) method.

The conventional fixed back-off radio frequency power is as follows: assuming that the maximum transmit power of the rf circuit is 23dBm, when the sar backoff mechanism is activated or triggered, the transmit power of the rf circuit is backoff at a fixed backoff value, e.g., 3dB, and the rf power after backoff is maintained at 20dBm for transmission. The TA-SAR method is a method for dynamically adjusting the conductive transmission power of the DUT in a longer time window to ensure that the average SAR does not exceed the standard. The TA-SAR mechanism allows the DUT to transmit at a power above P_limit (P_limit may be understood as the amount of radio frequency power corresponding to the upper limit of SAR value, if the radio frequency power is above P_limit, the corresponding SAR would exceed the upper limit) for some periods of time and below P_limit for some periods of time, but the average power over a certain time window is less than or equal to P_limit.

As shown in fig. 11, the TA-SAR mechanism allows the DUT to transmit at an instantaneous transmit power p_3 above p_limit for some periods of time, at an instantaneous transmit power p_1 below p_limit for some periods of time, and at an instantaneous transmit power p_2 above p_limit for some periods of time, but the average power over a time window (as shown by the dashed curve in fig. 11) is less than or equal to p_limit.

Currently, a TA-SAR method is mainly adopted. In the embodiment shown in fig. 10, the power of each transmission path of MIMO is the same, and a TA-SAR control method is used. The radio frequency system of the embodiment of the application comprises: a radio frequency transceiver 340, a first radio frequency path 310, a second radio frequency path 320, a detection path 330, and the like.

The radio frequency transceiver 340 has a first transmitting end and a second transmitting end and also has a detection port coupled to the detection path 330. The rf transceiver 340 is used for receiving and transmitting multiple rf signals and receiving feedback detection signals.

The first rf path 310 has one end connected to the first transmitting end and the other end connected to the first antenna 311. A first coupler 312 is provided on the first rf path 310, the first coupler 312 being located on the inlet side of the first antenna 311. The first coupler 312 is configured to sample the radio frequency signal in the first radio frequency path 310 to output a first coupled signal.

One end of the second rf path 320 is connected to the second transmitting end, the other end is connected to the second antenna 321, and a second coupler 322 is disposed on the second rf path 320, and the second coupler 322 is located at an inlet side of the second antenna 321. The second coupler 322 is configured to sample the radio frequency signal in the second radio frequency path 320 to output a second coupled signal.

An active divider 331 is provided in the detection path 330. The power divider 331 has a first input terminal, a second input terminal, and an output terminal, where the first input terminal is connected to the first coupler 312 and is configured to receive the first coupling signal; a second input terminal thereof is connected to the second coupler 322 for receiving a second coupling signal; the output end of the signal is connected with the radio frequency power meter 333 on the detection path, and is used for outputting a combined signal of the first coupling signal and the second coupling signal to the radio frequency power meter 333.

The output end of the detection path 330 is connected to the detection end of the radio frequency transceiver 340, and the power information detected by the radio frequency power meter 333 is input to the detection port of the radio frequency transceiver 340.

The working process of the embodiment of the application is described in detail below and mainly comprises the following three steps:

step one: test data of SAR values corresponding to different reflected powers are stored in advance

In the same state, SAR values corresponding to different reflected powers of the two MIMO antennas are tested, wherein the SAR value is the maximum value of the two antennas when the two antennas work simultaneously, namely the maximum SAR value after SAR superposition of the two antennas. A set of tables is obtained as shown in table 1 and stored in memory. The memory can be a mobile phone memory or a cloud memory.

TABLE 1

The different states refer to SAR under different model states of a human body model, a human head model and a local model, namely a test model of standard SAR.

Step two: detection of reflected power of two antennas

The rf transceiver 340 detects the sum of the reflected powers of the two antennas measured by the rf power meter 333 in real time.

Step three: adjustment control of TA-SAR value

And finding out a corresponding SAR value, namely a real-time SAR value, from the corresponding relation of the pre-stored table according to the sum of the measured reflected powers of the two antennas, and calculating an average SAR value within a window required by the regulations.

When the average SAR value is lower than the target TA-SAR value, the transmission power of the DUT is not adjusted.

When the average SAR value is close to the target TA-SAR value, software forcedly controls two radio frequency transmission paths to simultaneously reduce the transmission power, so that the reflected power is correspondingly reduced, and further SAR value reduction is realized. The control can be controlled by the DUT according to the received power control signaling of the network end, or can be controlled by the DUT according to the power control signaling of the local end.

As shown in fig. 12, since the transmission power of the radio frequency circuit of the mobile phone is changed all the time, the SAR value is also changed. The system monitors the average SAR values of the two antennas in an average time window, adjusts the transmitting power of the two radio frequency circuits according to the requirement, and ensures that the average SAR value is lower than a target TA-SAR value in a time window required by regulations so as to ensure TA-SAR compliance.

Another specific detection and control scheme for a radio frequency system is given below in connection with fig. 13, taking a detection path based on a radio frequency power meter as an example. In the embodiment shown in fig. 13, the transmission power of the two radio frequency paths is different, and the control of the TA-SAR value is based on the alternate detection of the transmission frequencies of the two lines. The radio frequency system of the embodiment of the application comprises: a radio frequency transceiver 440, a first radio frequency path 410, a second radio frequency path 420, a detection path 430, and the like.

The detection path 430 is provided with a switch 431 and a radio frequency power meter 433.

The switch 431 has a first input terminal, a second input terminal and an output terminal, wherein the first input terminal is connected to the first coupler 412 for receiving the first coupling signal; a second input terminal thereof is connected to the second coupler 422 for receiving a second coupled signal; the output end of the power meter is connected with a radio frequency power meter 433 on the detection path. When the switch 431 controls the first input end to be conducted with the output end, the switch 431 outputs a first coupling signal to the radio frequency power meter 433 through the output end thereof; when the switch 431 controls the second input terminal to be conducted with the output terminal, the switch 431 outputs the second coupling signal to the rf power meter 433 through the output terminal thereof.

When the switch 431 outputs the first coupling signal to the rf power meter 433, the rf power meter 433 is configured to perform power detection on the first coupling signal; when the switch 431 is switched to the second input terminal and the second coupling signal is output to the rf power meter 433, the rf power meter 433 is configured to perform power detection on the second coupling signal.

The output terminal of the rf power meter 433 is connected to the detection terminal of the rf transceiver 440, and the detected power information is input to the detection port of the rf transceiver 440.

Step one: test data of SAR values corresponding to different reflected powers of two antennas are stored in advance

In the same state, by testing the SAR values respectively corresponding to the different reflected powers of the first antenna 411 and the second antenna 421, the SAR value herein is a value when the two antennas operate independently, that is, a maximum SAR value when the two antennas transmit SAR independently. A set of tables is obtained as shown in table 2 and stored in memory. The memory can be a mobile phone memory or a cloud memory.

TABLE 2

Step two: alternate detection of two paths of reflected power

The rf transceiver 440 detects the reflected power of the first antenna 411 and the second antenna 421, which are alternately measured by the rf power meter 433, in real time, finds the corresponding SAR value, i.e., the real-time SAR value, from the correspondence of the table, and calculates the average SAR value of the two superimposed paths.

Step three: adjustment control of TA-SAR value

In some implementations, the transmit powers of the first antenna 411 and the second antenna 421 may be adjusted simultaneously, or only the transmit power of the antenna that dominates the SAR value may be adjusted. The antenna having the dominant SAR value, i.e. the antenna having the larger SAR value when the first antenna 411 and the second antenna 421 are operated simultaneously.

When the superimposed average SAR value is lower than the target TA-SAR value, the transmission power of the DUT is not adjusted.

When the superimposed average SAR value is close to the target TA-SAR value, the control software can forcedly control the two radio frequency circuits to reduce the transmitting power simultaneously, and the control software can forcedly control the dominant radio frequency circuit to reduce the transmitting power independently, so that the reflected power is correspondingly reduced, and further the SAR value is reduced. The control can be controlled by the DUT according to the received power control signaling of the network end, or can be controlled by the DUT according to the power control signaling of the local end.

Through the control, the average SAR value of the two paths of superposition is lower than the target TA-SAR value within the window required by the regulation.

The test models of the applicable standard SAR are different in different states of the wireless communication equipment, namely the safety values of the SAR in different model states of the human body model, the human head model and the local model are different.

The wireless communication equipment needs to determine the current working state, determine the applicable model of the SAR value, and adjust the SAR value compliance according to the radio frequency power after determining the applicable model of the SAR value. The wireless communication device may detect the current state through a sensor, and in some implementations, an SAR sensor is added from the antenna to the radio frequency end, and the SAR sensor may sense whether the peripheral capacitance changes through the antenna, thereby determining whether the human body is close to the electronic device.

In general, the variation of the electrical characteristics of the antenna signal caused when approaching the mobile terminal is different due to different substances, such as human body, metal, wood, cement, etc., and the influence of the different substances on the electrical characteristics of the antenna signal has uniqueness. The electrical characteristics of the antenna signal change, and the corresponding return loss of the radio frequency circuit also changes, so that the current state of the equipment can be identified by detecting the change of the return loss of the antenna.

The return loss of an antenna is also called the reflection coefficient of the antenna (S11 parameter), and can be determined by the ratio of the transmission power to the reflection power of a radio frequency circuit, or by detecting the ratio of the input power to the reflection power of the antenna. In general, the signal strength of an antenna is different in different scenarios, and the coupled signal generated after coupling is also different. In some implementations, the antenna signal may be perceived as being coupled by a bi-directional coupler, thereby causing a change in return loss, and identifying different scene states according to the change in return loss.

A specific manner of detection and control of the multiple radio frequency system is described below with reference to fig. 13, taking return loss based state identification as an example. In the embodiment shown in fig. 13, the transmission power of the two radio frequency circuits is different, and the control of the TA-SAR value is based on the alternate detection of the transmission frequency. The components of the rf system according to the embodiments of the present application have been described above and will not be described in detail.

The working process of the embodiment of the application is described in detail below, and mainly comprises the following steps:

step one: test data of SAR values corresponding to different reflected powers of two antennas under different states are stored in advance

By testing the SAR values of the wireless device corresponding to the reflected powers of the first antenna 411 and the second antenna 421 respectively in different states, the SAR value herein is a value when the two antennas operate independently, that is, a maximum SAR value when the two antennas transmit SAR independently. A group of tables are obtained as shown in Table 3 and are stored in a memory of the mobile terminal in advance to be used as the basis for judging different test models of SAR. It should be noted that the pre-stored characteristics may be stored in the mobile terminal, or may be obtained from the cloud server at the mobile terminal.

TABLE 3 Table 3

Step two: alternate detection of two paths of reflected power and state recognition

The rf transceiver 440 detects the power of the coupling signals of the first antenna 411 and the second antenna 421 alternately measured by the rf power meter 433 in real time, calculates the reflected power, calculates the return loss of the antenna according to the detected transmitted power and reflected power, and finds the corresponding state from the correspondence of the table.

Step three: according to the detected reflected power, calculating the average SAR value of two paths of superposition

In the corresponding state, according to the reflected power of the first antenna 411 and the second antenna 421, the corresponding SAR values, that is, the real-time SAR values, are found from the corresponding relation of the table, and the average SAR values of the two paths of superposition are calculated.

Step four: control of TA-SAR values

The control of the TA-SAR value may adjust the transmit power of the first antenna 411 and the second antenna 421 simultaneously. In some implementations, the transmit power of only the antenna that dominates the SAR value may also be adjusted. The antenna having the dominant SAR value, i.e. the antenna having the larger SAR value when the first antenna 411 and the second antenna 421 are operated simultaneously.

When the superimposed average SAR value is close to the target TA-SAR value, the control software can forcedly control the two radio frequency transmitting circuits to simultaneously reduce the transmitting power, and the control software can forcedly control the dominant radio frequency transmitting circuit to independently reduce the transmitting power, so that the reflected power is correspondingly reduced, and further the SAR value is reduced. The control can be controlled by the DUT according to the received power control signaling of the network end, or can be controlled by the DUT according to the power control signaling of the local end.

Through the steps, the average SAR value of the two paths of superposition is lower than the target TA-SAR value within the window required by the regulations.

Fig. 14 is a schematic block diagram of a wireless communication device provided in an embodiment of the present application. The wireless communication device 700 shown in fig. 14 may be a device that provides voice and/or data connectivity to a user, and may be used to connect people, things, and machines, such as a handheld device, an in-vehicle device, etc. with wireless connection capabilities. The wireless communication device in the embodiments of the present application may be, for example, a mobile phone (mobile phone), a tablet (Pad), a notebook, a palm, a mobile internet device (mobile INTERNET DEVICE, MID), a wearable device, a Virtual Reality (VR) device, an augmented reality (augmented reality, AR) device, a wireless terminal in industrial control (industrial control), a wireless terminal in unmanned (SELF DRIVING), a wireless terminal in teleoperation (remote medical surgery), a wireless terminal in smart grid (SMART GRID), a wireless terminal in transportation security (transportation safety), a wireless terminal in smart city (SMART CITY), a wireless terminal in smart home (smart home), or the like.

Referring to fig. 14, the wireless communication device 700 may include a baseband system 710 and a radio frequency system 720. The baseband system 710 may be used for the generated baseband signal. The radio frequency system 720 may be configured to generate radio frequency signals from the baseband signals generated by the baseband system 710. The rf system 720 may employ any of the rf systems described in any of the previous embodiments.

The system embodiment of the present application is described in detail above with reference to fig. 1 to 14, and the SAR value control method embodiment of the present application is described in detail below with reference to fig. 15 to 17. It is to be understood that the description of the method embodiments corresponds to the description of the system embodiments, and that parts not described in detail may therefore be referred to the previous system embodiments.

Fig. 15 is a schematic flowchart of a SAR value control method according to an embodiment of the present application. The method of fig. 15 may be applied to any of the radio frequency systems mentioned in the previous embodiments.

The radio frequency system may include: the radio frequency transceiver is provided with a first transmitting end, a second transmitting end and a detecting end; the antenna comprises a first radio frequency channel, a second antenna and a third antenna, wherein one end of the first radio frequency channel is connected with a first transmitting end, and the other end of the first radio frequency channel is connected with the first antenna; the second radio frequency channel, one end of the second radio frequency channel is connected with the second transmitting end, the other end of the second radio frequency channel is connected with the second antenna, wherein a second coupler is arranged on the second radio frequency channel and used for sampling radio frequency signals in the second radio frequency channel so as to output second coupling signals; the detection path is connected with the detection end, a power detector is arranged on the detection path and is used for carrying out power detection on the first coupling signal and the second coupling signal, and the detection result of the power detection is output to the radio frequency transceiver through the detection end.

The method of fig. 15 may include step S1510 and step S1520, which are illustrated in detail below.

In step S1510, the SAR value of the electronic device is acquired according to the detection result. The SAR value may be a real-time SAR value of the electronic device.

In some embodiments, mapping relation information among the use state of the electronic device, the detection result of the detection end and the SAR value may be stored in advance, and then, according to the use state of the electronic device and the detection result of the detection end, the SAR value of the electronic device may be obtained by searching the mapping relation information.

Taking the detection result of the detection end as an example of the detection result of the reflected power of the antenna, the mapping relation information mentioned herein may be a mapping relation table shown in table 1 (see the foregoing for table 1). After the detection end detects the reflected power of the antenna, the SAR value of the electronic equipment can be determined by looking up the table 1 in combination with the use state of the electronic equipment.

In step S1520, the transmission power of the first antenna and/or the second antenna is adjusted according to the SAR value of the electronic device. In some embodiments, step S1520 may control the average SAR value per unit time so that the average SAR value per unit time of the electronic device is less than or equal to the preset threshold. The unit time may be a time window or time period required by regulations. The average SAR value per unit time may be the maximum value within the time window required by the regulations. Taking the FCC standard as an example, for radio frequency signals below 3GHz, the average SAR value within the time window of 100 seconds is required not to exceed the upper limit requirement of 1.6W/kg. Thus, to meet the requirements of the FCC standard, the average SAR value of the electronic device over 100 seconds may be controlled such that it is less than or equal to 1.6W/kg.

Fig. 16 is a schematic flow chart of a SAR value regulation method for power combining detection, which is provided in an embodiment of the present application, and the state of the method is determined. As shown in fig. 16, the method includes steps S1610 to S1660.

In step S1610, test data of SAR values corresponding to different reflected powers of the two antennas in the same state are stored in advance.

In step S1620, the sum of the reflected powers of the two antennas is detected.

In step S1630, a TA-SAR value is calculated according to the sum of the detected reflected powers and the mapping relation between the transmission power of the prestored antenna and the SAR value.

In step S1640, determine whether the calculated average SAR value is lower than the target TA-SAR value? If so, go to step 1550; if the preset condition is not met, step 1660 is entered.

In step S1650, no adjustment is made to the transmit power of the DUT.

In step S1660, two radio frequency transmit paths are controlled to simultaneously reduce transmit power, thereby controlling TA-SAR to meet compliance requirements.

In some implementations, a power-alternate detection manner of multiple radio frequency signals is adopted, and fig. 17 is a schematic flowchart of another SAR value regulation method provided in an embodiment of the present application. As shown in fig. 17, the method includes steps S1710 to S1770.

In step S1710, test data of SAR values corresponding to different reflected powers of the two antennas in different states are stored in advance.

In step S1720, the power of the coupled signals of the two antennas is alternately detected.

In step S1730, reflected power is calculated from the power of the coupling signal of the detection antenna, and return loss of the antenna is calculated from the detected transmitted power and reflected power. And identifying a state model according to the return loss and the mapping relation between the return loss and the state, which are stored in advance.

In step S1740, a real-time superposition average SAR value is calculated according to the detected power of the coupling signal and the pre-stored mapping relationship between the transmission power of the two antennas and the SAR value in a certain state.

In step S1750, it is determined whether the calculated superimposed average SAR value is lower than the target TA-SAR value? If so, go to step 1760; if the preset condition is not satisfied, step 1770 is entered.

In step S1760, no adjustment is made to the transmit power of the DUT.

In step S1770, both radio frequency channels are controlled to simultaneously reduce the transmit power. In some implementations, the dominant radio frequency path may also be controlled to reduce transmit power, thereby controlling the average SAR value to meet compliance requirements.

The embodiment of the application adopts a radio frequency system and an SAR value regulation method, wherein a detection passage is respectively connected with a plurality of radio frequency passages, the coupling signals of the radio frequency passages are alternately power-detected or combined-detected, and the power detection result of the radio frequency passages is used for SAR value control when the radio frequency system works. Compared with the multipath detection channels adopted in the related art, the power detection of the multi-antenna radio frequency system can be realized only by one path of detection channel, the use requirement of multipath power detection is met, and the hardware cost is reduced. According to the embodiment of the application, the radio frequency power meter is adopted to replace a power detection path to measure the power of the signal, filtering, frequency reduction, demodulation and the like are not needed, nonlinearity generated by active nonlinear devices such as LNA, mixer and the like is removed, interference among systems is reduced, the power of the coupling signal can be directly obtained, and smaller error is realized.

It should be understood that, in various embodiments of the present application, "first," "second," etc. are used for distinguishing between different objects and not for describing a particular sequence, and the size of the sequence numbers of the above-described processes does not imply that the order of execution should be determined by the functions and inherent logic of each process, and should not be construed as limiting the implementation of the embodiments of the present application.

In the several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.

The foregoing is merely illustrative of the present application, and the present application is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A radio frequency system, comprising:

The radio frequency transceiver is provided with a first transmitting end, a second transmitting end and a detecting end;

A first radio frequency path, one end of the first radio frequency path is connected with the first transmitting end, the other end of the first radio frequency path is connected with a first antenna, the first coupler is used for sampling radio frequency signals in the first radio frequency channel so as to output first coupling signals;

The second radio frequency channel, one end of the second radio frequency channel is connected with the second transmitting end, the other end of the second radio frequency channel is connected with the second antenna, wherein a second coupler is arranged on the second radio frequency channel and is used for sampling radio frequency signals in the second radio frequency channel so as to output second coupling signals;

The detection path is connected with the detection end, a power detector is arranged on the detection path and is used for carrying out power detection on the first coupling signal and the second coupling signal, and a detection result of the power detection is output to the radio frequency transceiver through the detection end;

The detection path is provided with a combiner, the combiner is provided with a first input end, a second input end and an output end, the first input end is connected with the first coupler and is used for receiving the first coupling signal, the second input end is connected with the second coupler and is used for receiving the second coupling signal, and the output end is connected with the power detector and is used for outputting a combined signal of the first coupling signal and the second coupling signal to the power detector;

And the radio frequency transceiver adjusts the transmitting power according to the detection result and the SAR value corresponding to the detection result so as to control the SAR value when the first antenna and/or the second antenna work.

2. The radio frequency system according to claim 1, wherein a switch is provided on the detection path, the switch having a first input terminal, a second input terminal and an output terminal, the first input terminal being connected to the first coupler for receiving the first coupling signal, the second input terminal being connected to the second coupler for receiving the second coupling signal, the output terminal being connected to the power detector;

When the switch controls the first input end to be conducted with the output end, the switch outputs the first coupling signal to the power detector through the output end;

When the switch controls the second input end to be conducted with the output end, the switch outputs the second coupling signal to the power detector through the output end.

3. The radio frequency system according to claim 1, wherein the power detector comprises a radio frequency power meter for directly power detecting radio frequency power of the first coupling signal and/or the second coupling signal.

4. The radio frequency system of claim 1, wherein the first antenna and the second antenna are configured for MIMO operation or CA operation.

5. A SAR value regulation method, wherein the method is applied to a radio frequency system, the radio frequency system comprising:

the method comprises the following steps:

acquiring an SAR value of the electronic equipment according to the detection result;

And adjusting the transmitting power of the first antenna and/or the second antenna according to the SAR value of the electronic equipment.

6. The method of claim 5, wherein the obtaining the SAR value of the electronic device based on the detection result comprises:

Acquiring the use state of the electronic equipment;

and according to the use state and the detection result, acquiring the SAR value of the electronic equipment by searching pre-stored mapping relation information, wherein the mapping relation information records the mapping relation among the use state, the detection result and the SAR value.

7. The method of claim 5, wherein adjusting the transmit power of the first antenna and/or the second antenna according to the SAR value of the electronic device comprises:

And adjusting the transmitting power of the first antenna and/or the second antenna according to the SAR value of the electronic equipment so that the average SAR value of the electronic equipment in unit time is smaller than or equal to a preset threshold value.

8. The method of claim 5, wherein a radio frequency power meter is disposed on the detection path, and wherein the radio frequency power meter is utilized to directly perform power detection on the radio frequency power of the first coupling signal and/or the second coupling signal.

9. The method of claim 5, wherein the first antenna and the second antenna are used for MIMO operation or CA operation.