KR100859528B1 - Microwave motion sensor module to decrease electromagnetic interference - Google Patents

Abstract

A microwave motion sensor module is provided to improve motion sensing accuracy by converting a receiver signal to an IF signal, averaging the IF(Intermediate Frequency) signals for a few periods, and comparing the average result with a threshold value. A power source(230) converts an AC voltage to a DC voltage. A sensor unit(210) includes a local signal generator, an antenna transmitter, an antenna receiver, a frequency mixer, and an IF output stage. The local signal generator repeatedly generates UHF(Ultra High Frequency) signals. The antenna receiver receives the signal reflected from an object. The frequency mixer converts a transmission frequency signal and the reception frequency signal to an IF signal. The IF output stage filters out the signals except for the IF signal. An IF processor(220) includes an IF amplifier, a signal determining unit, and a periphery controller. The IF amplifier amplifies the IF signal. The signal determining unit determines whether an object exists and determines a moving speed of the object. The periphery controller controls peripheral devices based on the signal from the signal determining unit. An EMC(ElectroMagnetic Compatibility) filter is mounted on a micro strip power line of the antenna transmitter and antenna receiver. A voltage regulator reduces a voltage ripple at an output side of the power source.

Description

Microwave motion sensor module for decrease electromagnetic interference

1 is a block diagram of a microwave sensor module according to the prior art.

Figure 2 is a block diagram of a microwave actuated sensor module for reducing electromagnetic interference in accordance with the present invention.

3 is a diagram illustrating a microwave actuated sensor module substrate for reducing electromagnetic interference in which the EMC filter of FIG. 2 is implemented.

<Code Description of Main Parts of Drawing>

210: sensor unit 211: local signal generator

212: antenna transmitter 213: antenna receiver

214: frequency mixer 215: intermediate frequency output stage

216, 217: first and second EMC filter 220: intermediate frequency processing unit

221: intermediate frequency amplifier 222: signal determination unit

223: peripheral device control unit 224: integrator or averager

230: power supply unit 231: voltage stabilization circuit

The present invention relates to a microwave sensor module, and more particularly, an EMC filter is added to the antenna transmitter and the antenna receiver, and a plurality of voltage regulators are connected in cascading to the output side of the power supply, and a mobile body exists. When determining the presence or absence of electromagnetic waves after converting the signal detected by the antenna receiver into an intermediate frequency, it is integrated or averaged for integer times of the AC power cycle, and it is determined that the moving object is detected when the value is above or below a certain amount. A microwave actuating sensor module for interference reduction.

In general, the microwave sensor module detects the presence of the object, the movement and the speed of the object according to the Doppler radar principle, that is, the frequency change caused by the relative motion between the wave source and the object, and controls the driving of the associated peripheral device. It is a device that outputs a signal.

Next, a block diagram of a microwave sensor module according to the related art will be described with reference to FIG. 1.

As shown in FIG. 1, the microwave sensor module according to the related art includes a sensor unit 110 that detects the presence and movement of an object, software that receives signals output from the sensor unit 110, and includes built-in software. Intermediate frequency processing unit 120 to process the signal by the interaction of the control unit based on the result, and a power supply unit for applying the operating power to the sensor unit 110 and the intermediate frequency processing unit 120 It consists of 130.

Here, the sensor unit 110 and the intermediate frequency processing unit 120 will be described in more detail.

The sensor unit 110 includes a local signal generator 111 for continuously oscillating microwaves according to a predetermined frequency range, and an antenna transmitter 112 for transmitting microwaves generated by the local signal generator 111 to a space. An antenna receiver 113 for receiving a transmission frequency signal transmitted from the antenna transmitter 112 or a signal transmitted from the antenna transmitter 112 and reflected back from an object; and the transmission frequency signal and the antenna receiver 113 And a frequency mixer 114 for mixing the received frequency signals received through the power signal to allow the conversion of the center frequency, and an intermediate frequency output stage 115 for filtering the intermediate frequency signal thrust from the frequency mixer. do.

The intermediate frequency processor 120 is an intermediate frequency amplifier 121 for amplifying the intermediate frequency signal output from the intermediate frequency output terminal 115 of the sensor unit 110 to an appropriate level, and the intermediate frequency amplifier 121 A signal determining unit 122 that determines whether an object exists by using the signal amplified by the controller, and a peripheral device controller which outputs a control signal for driving the peripheral device according to the signal output from the signal determining unit 122. 123 is configured.

In the conventional microwave operating sensor module as described above, when the connection terminal of the adapter for supplying DC power of 5 to 12V is connected to the input terminal of the power supply unit 130 and power is applied, the sensor unit 110 and the The intermediate frequency processor 120 is operated to output a control signal through the peripheral device controller 123.

When power is applied through the power supply unit 130, the local signal generator 111 continuously oscillates a specific frequency of 1 to 30 GHz band, and when the frequency signal oscillated through the antenna transmitter 112 is emitted into the air. In the standby state in which the object is not accessible, the antenna receiver 113 receives the transmission frequency signal emitted through the antenna transmitter 112 and passes through the frequency mixer 114 to the intermediate frequency output terminal 115. It flows in.

However, if the movement due to the approach of the object is captured by the operation sensor by transmitting the frequency signal oscillated through the antenna transmitter 40, the signal reflected back through the object is returned from the existing antenna transmitter 112 Away from the transmit frequency.

The reception frequency signal received through the antenna receiver 113 and the signal generated from the local signal generator 111 and the same signal as the transmission frequency signal are mixed with each other through the frequency mixer 114 and the intermediate frequency output terminal 115 is connected. Through this series of processes, the sensor unit 110 calculates a low frequency voltage, and the low frequency voltage calculated by the sensor unit 110 operates between the operation of the intermediate frequency processor 120 and an embedded program. It is processed according to the command specified for each purpose of the sensor by, and finally the operation of the peripheral device is made through the peripheral device control unit 123.

These microwave sensor modules are in the spotlight more recently than other operating sensors due to their superior sensitivity compared to infrared and ultrasonic sensors, and are widely used for intrusion alarms, automatic doors, flashing lights, men's urinals, car rear object detection and automatic hair dryers. .

However, the conventional microwave operation sensor module is caused by mutual electromotive force in the inductor or capacitor used in the power supply unit 130, the ripple of the DC power supply or floating ground increases, the overall module becomes unstable, or connected to the power supply unit 130 The DC power line and the floating ground itself may directly cause magnetic coupling, or may malfunction due to the reception of the electromagnetic signals generated by the antenna transmitter 112 and the antenna receiver 113 from the peripheral device.

For example, when the microwave operating sensor module is used around a relatively large power-consuming electronic device such as an air conditioner, a heater, or a large capacity motor, the microwave operating sensor module may be coupled with the electromagnetic interference of the peripheral device to cause a malfunction. have.

Alternatively, the power supply unit, which is a low-cost inductor-less capacitive AC-DC converter or a low power switching-mode power supply (SMPS), has a large output voltage ripple of 1 Vpp or more when the AC-DC converter is used. In the case of using the low power SMPS, the switching frequency may be several tens of kHz and the line frequency may also increase by more than 100 mVpp, causing noise in the sensor unit and the intermediate frequency processing unit.

The present invention has been made to solve the above-mentioned problems, an object of the present invention to minimize the malfunction caused by the instability of the power supply, and to provide a microwave operation sensor module for reducing the electromagnetic interference to improve the efficiency of the product without malfunction even in a harsh environment. It is.

As a technical configuration for achieving the above object, the present invention provides a microwave operation sensor module for reducing electromagnetic interference by oscillating a frequency signal of the GHz band in real time to detect a change in the movement of the object,

A power unit converting AC power into DC power;

A local signal generator for continuously oscillating microwaves, an antenna transmitter for firing microwaves generated by the local signal generator, and a transmission frequency signal emitted through the antenna transmitter or a transmission frequency signal emitted from the antenna transmitter is reflected from an object. An antenna receiver for receiving the returned signal, a frequency mixer for converting the signal into an intermediate frequency using the transmission frequency signal and the reception frequency signal received through the antenna receiver, and an intermediate frequency output stage for filtering signals other than the intermediate frequency. A configured sensor unit; And

An intermediate frequency amplifier for amplifying the intermediate frequency signal output from the intermediate frequency output terminal, a signal determination unit for determining the presence and speed of an object by signal processing the intermediate frequency signal amplified by the intermediate frequency amplifier, and the signal And an intermediate frequency processor configured as a peripheral device controller to control the peripheral device based on the signal output from the determination unit.

An EMC filter is mounted on the microstrip feed line of the antenna transmitter and the antenna receiver, and a voltage regulator is mounted on the output side of the power supply to reduce ripple of the operating power.

The method may further include an integrator or an averager which integrates or averages the amplified signal at the output terminal of the intermediate frequency amplifier.

In addition, the voltage regulator is characterized in that the two to five in series connected.

In addition, the EMC filter is characterized by consisting of capacitance of several to several tens of pF.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention in more detail as follows. The accompanying drawings are only examples to specifically describe one embodiment of the present invention, and the scope of the present invention is not limited or limited by the drawings or the description with reference to the drawings.

Figure 2 is a block diagram of a microwave actuated sensor module for reducing electromagnetic interference according to the present invention, Figure 3 is a view showing a module substrate actually implementing the EMC filter of FIG.

As shown in FIG. 2, the microwave sensor module according to the present invention includes a sensor unit 210 that detects the presence and movement of an object, and a built-in software that receives a signal output from the sensor unit 210. Intermediate frequency processing unit 220 to process the signal by interaction and control the peripheral device based on the result, and converts AC power into DC power to the sensor unit 210 and the intermediate frequency processing unit 220 It is composed of a power supply unit 230 for applying the operating power.

The sensor unit 210, the intermediate frequency processing unit 220, and the power supply unit 230 will be described in more detail.

The sensor unit 210 includes a local signal generator 211, a first EMC filter 216, an antenna transmitter 212, an antenna receiver 213, a second EMC filter 217, a frequency mixer 214, and an intermediate part. The frequency output stage 215 is configured.

Here, the local signal generator 211 continuously oscillates microwaves according to a predetermined frequency range. The frequency of the microwaves oscillated by the local signal generator 211 is preferably 10.525 GHz. This contributes to miniaturization of the device while minimizing interference with other existing service signals.

In addition, the antenna transmitter 212 launches the microwave generated by the local signal generator 211 into the space.

In addition, the first EMC filter 216 filters the electromagnetic waves in the vicinity applied through the antenna transmitter 212 between the local signal generator 211 and the antenna transmitter 212.

In addition, the antenna receiver 213 receives a signal in which a transmission frequency signal emitted through the antenna transmitter 212 or a transmission frequency signal emitted from the antenna transmitter is reflected on an object and returned.

In addition, the second EMC filter 217 filters the electromagnetic waves that are applied between the antenna receiver 213 and the frequency mixer 214 through the antenna receiver 212.

In addition, the frequency mixer 214 converts the frequency mixer to an intermediate frequency using the microwave generated by the local signal generator 211 and the received frequency signal received through the antenna receiver 213.

In addition, the intermediate frequency output stage 215 filters the intermediate frequency signal output from the frequency mixer 214.

The intermediate frequency processor 220 includes an intermediate frequency amplifier 221, an integrator or averager 224, a signal determiner 222, and a peripheral device controller 223.

Here, the intermediate frequency amplifier 221 amplifies the intermediate frequency signal output from the intermediate frequency output terminal 215 to an appropriate level. In some cases, a voltage stabilizer may be further mounted on the output side of the intermediate frequency amplifier 221.

In addition, the integrator or the averager 214 AC power amplified by the intermediate frequency amplifier 221 at the front end of the signal determination unit 222, that is, the output terminal of the intermediate frequency amplifier 221 Integrate or average over an integer multiple of the period to detect when the value is above or below a certain amount. The integration method at this time is as shown in Equations 1 and 2 below.

sum =

sum =

sum =

sum =

Here, v (ti) is an intermediate frequency signal at ti time, N is a sampling number, m is a natural number, and TAC is a period of an AC power source.

Equation 1 is a case of integrating with a digital circuit using a microcomputer or the like, and Equation 2 is an case of integrating using an analog circuit such as an integrator. In practical terms, the integral period Ti is most effective when it is an integer multiple of the period of the alternating current.

In addition, the signal determination unit 222 signals the signal through the integrator or averager 214 to determine the presence and speed of the object.

In addition, the peripheral device controller 223 generates a control signal for driving the peripheral device according to the signal output from the signal determination unit 222 and applies it to the associated peripheral device.

The power supply unit 230 includes a voltage stabilizer circuit 231 having a voltage regulator connected to a cascade of output and output terminals on the output side, so that the sensor unit 210 and the intermediate frequency processor 220 are connected. Greatly reduce the ripple of the operating power supplied to the

Preferably, the voltage stabilizer uses a 50 dB ripple rejection two voltage stabilizers 231a, 231b so that the ripple of the operating power source is at most 10 μVpp. More preferably, the voltage regulator connects two to five in series.

As shown in FIG. 3, the first EMC filter EMC1 is connected in series on a feed line PWL1 that supplies power to the antenna patch ANT1 of the antenna transmitter 212 and the second EMC filter EMC1. The filter EMC2 is connected in series on a feed line PWL2 that supplies power to the antenna patch ANT2 of the antenna receiver 213.

In this case, the first and second EMC filters EMC1 and EMC2 may configure capacitors having capacitances of several to several tens of pF in series on the feed lines PWL1 and PLW2. In other words, by cutting the feed lines PWL1 and PLW2, the capacitors are connected between the cut feed lines PWL1 and PLW2 so that the cut feed lines PWL1 and PLW2 are connected again through the capacitors.

Looking at the process of the detection of the object by the microwave operation sensor module for reducing electromagnetic interference according to the present invention as follows.

First, when a connection terminal of an adapter for supplying DC power of 5 to 12 V is connected to an input terminal of the power supply unit 230 and power is applied, the regulator unit of the power supply unit removes the ripple of the DC power supply to the sensor unit. By supplying operating power to the intermediate frequency processor, the sensor unit 210 and the intermediate frequency processor 220 are operated in an initialized state so that a control signal is output through the peripheral device controller 223.

In this case, when the operating power is applied through the power supply unit 230, the local signal generator 211 continuously oscillates a specific frequency of 10.525 GHz, and oscillates in the local signal generator through the antenna transmitter 212. When the 10.525 GHz transmission frequency signal is emitted into the air, the antenna receiver 213 receives the frequency emitted by the antenna transmitter 212 in the standby state where the object is not approached, and thus the frequency mixer 214. After passing through), it flows into the intermediate frequency output terminal 215.

On the other hand, if the movement of the object is captured by the operation sensor when the frequency of 10.525 GHz oscillated from the local signal generation is emitted into the air through the antenna transmitter 212, the object is detected. The reception frequency signal reflected and returned through the antenna is spaced apart from the transmission frequency transmitted from the existing antenna transmitter 212.

The transmission frequency signal and the reception frequency signal are mixed with each other through the frequency mixer 214 and then passed through the intermediate frequency output terminal 215. Through this process, the sensor unit 210 receives a low frequency voltage. The calculated low frequency voltage is processed according to a command designated by the purpose of each sensor by the operation between the operation of the intermediate frequency processing unit 220 and the built-in program, and finally the peripheral device control unit 223 Allow operation to take place.

In the present specification and drawings, preferred embodiments of the present invention have been disclosed, and although specific terms have been used, these are merely used in a general sense to easily explain the technical content of the present invention and to help the reader to understand the present invention. It is not intended to limit the scope. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention can be carried out in addition to the embodiments disclosed herein. The scope of the invention is shown in the following claims.

As described above, the microwave operation sensor module for reducing the electromagnetic interference of the present invention is mounted in one module, the antenna transmitter and the antenna receiver to oscillate the frequency signal of the GHz band in real time to detect the change of the movement on the object. In addition, an EMC filter including at least one of a resistor, a capacitor, and an inductor is added to the antenna transmitter and the antenna receiver to filter out electromagnetic waves by surrounding electronic devices, thereby minimizing detection errors due to electromagnetic interference of peripheral devices. Signals detected through the antenna receiver when minimizing malfunction due to power instability and determining the presence of a moving object by using a plurality of voltage regulators connected in cascading to the output of the DC-converted power source Is an integer multiple of the AC power cycle after converting By integrating or averaging it over time, it is determined that the moving object is detected when the value is above or below a certain amount, so that it can be used without malfunction even in a harsh environment, thereby improving the efficiency of the product and enhancing the competitiveness of the sensor device. There is.

Claims (4)

In the microwave sensor module for reducing the electromagnetic interference to oscillate the frequency signal of the GHz band in real time to detect a change in the movement of the object, A power unit converting AC power into DC power; A local signal generator for continuously oscillating microwaves, an antenna transmitter for firing microwaves generated by the local signal generator, and a transmission frequency signal emitted through the antenna transmitter or a transmission frequency signal emitted from the antenna transmitter is reflected from an object. An antenna receiver for receiving the returned signal, a frequency mixer for converting the signal into an intermediate frequency using the transmission frequency signal and the reception frequency signal received through the antenna receiver, and an intermediate frequency output stage for filtering signals other than the intermediate frequency. A configured sensor unit; And An intermediate frequency amplifier for amplifying the intermediate frequency signal output from the intermediate frequency output terminal, a signal determination unit for determining the presence and speed of an object by signal processing the intermediate frequency signal amplified by the intermediate frequency amplifier, and the signal And an intermediate frequency processor configured as a peripheral device controller to control the peripheral device based on the signal output from the determination unit. An microwave filter is mounted on the microstrip feed line of the antenna transmitter and the antenna receiver, and a voltage regulator is mounted on the output side of the power supply to reduce the ripple of the operating power. Operation sensor module. The method of claim 1, Microwave interference sensor module further comprises an integrator or an averager for integrating or averaging the amplified signal at the output terminal of the intermediate frequency amplifier. The method of claim 1, The voltage regulator is a microwave actuated sensor module for reducing electromagnetic interference, characterized in that the two to five in series connected. The method of claim 1, The EMC filter is microwave active sensor module for electromagnetic interference reduction, characterized in that consisting of capacitance of several to several tens of pF.

Images