TWI684771B - System for measuring electrical parameters - Google Patents

Abstract

A system for measuring electrical parameters comprises an electromagnetic wave transceiver device and a determining device. The electromagnetic wave transceiver device comprises a signal transceiver unit, a transmitting unit and a receiving unit. The signal transceiver unit outputs a radio frequency test signal, and the transmitting unit is electrically connected to the signal transceiver unit to receive the radio frequency test signal and is converted into a test electromagnetic wave which is substantially a uniform plane wave, and the transmitting unit radiates the test electromagnetic wave to a material to be tested. The transceiver unit is further electrically connected to the receiving unit, and the signal transceiver unit further receives the portion of the test electromagnetic wave that penetrates the material to be tested through the receiving unit. The determining device is electrically connected to the signal transceiver unit, and constructs a measuring radiation field according to the portion of the test electromagnetic wave that penetrates the material to be tested, and uses the difference between the measured radiation pattern and a reference radiation pattern to determine a set of electrical parameters when the material to be tested operates at an RF frequency.

Description

Electrical parameter measurement system

The invention relates to a measurement system; in particular, a system for measuring electrical parameters of materials.

The parallel plate capacitance method is the earliest method to measure the dielectric constant of a material. By placing the material to be tested in a parallel plate and measuring the change in capacitance, the relative dielectric value can be obtained according to the geometry. Provide accurate dielectric constant simply.

The disadvantage of the parallel plate capacitance method is that when the frequency is greater than 1 GHz, the frequency of the time-varying field changes too fast, causing the error to gradually increase, which does not meet the needs of today's high-frequency communication.

Another method of measuring the resonant cavity is to place the material to be tested into the previously designed resonant cavity, and to obtain the dielectric constant of the material by measuring the amount of change in the resonant frequency inside the cavity when measuring the presence or absence of the material. Since the shape of the material does not necessarily fit exactly the size of the cavity, its air pores often become a source of error. Due to the selected modal relationship, the waves of other modalities are often excited due to the uneven material surface, resulting in errors. For those materials that cannot fill the cavity, the common solution to the size and placement is the cavity perturbation method. By obtaining the constant value related to the material and the cavity geometry in the selected mode, The dielectric constant and dielectric loss are obtained from the change in resonance frequency and the quality factor.

The disadvantage of this resonant cavity measurement method is that the material to be measured must be accurately made into a specific geometric shape, which is inconvenient for practical application, and because of the relationship of the cavity, it can usually only be obtained at a selected single operating frequency The electrical parameters of the material.

Since the known methods have the aforementioned problems, it is necessary to develop an electrical parameter measurement system that can solve the aforementioned shortcomings.

The first preferred embodiment of the electrical parameter measurement system of the present invention is suitable for measuring electrical parameters of a material to be measured. The first preferred embodiment includes an electromagnetic wave transceiver device and a determination device.

The electromagnetic wave transceiving device includes a signal transceiving unit, a transmitting unit and a receiving unit.

The signal transceiving unit outputs a radio frequency test signal, the transmitting unit is electrically connected to the signal transceiving unit to receive the radio frequency test signal and converts it into a uniform plane wave test electromagnetic wave, and the transmitting unit radiates the test electromagnetic wave toward the material to be tested, The signal transceiving unit is further electrically connected to the receiving unit, and the signal transceiving unit further receives the portion of the test electromagnetic wave penetrating the material to be tested through the receiving unit.

The judging device is electrically connected to the signal transceiving unit, and constructs a measurement radiation pattern according to the portion of the test electromagnetic wave penetrating the material to be measured, and uses the difference between the measurement radiation pattern and a reference radiation pattern A set of measured electrical parameters when the material to be tested operates at a radio frequency.

Preferably, the reference radiation pattern is that when the transmitting unit and the receiving unit are in free space, the judging device is based on the test electromagnetic wave received by the receiving unit Partially constructed, and the set of measured electrical parameters includes a dielectric constant and a dielectric loss when the material to be tested operates at the radio frequency, the determination device uses the measured radiation pattern and the reference The directivity difference of the radiation field type is used to determine the dielectric constant, and the gain difference between the measured radiation field type and the reference radiation field type is used to determine the dielectric loss.

Preferably, the first preferred embodiment further includes an electric wave anechoic chamber, and the electromagnetic wave transceiving device is disposed in the electric wave anechoic chamber, and the electric wave anechoic chamber and the electromagnetic wave transceiving device form a contracted field (Compact Antenna Test Ranges, CATR) Antenna measurement system.

Preferably, the signal transceiving unit includes a vector network analyzer, the transmitting unit includes a parabolic antenna, the parabolic antenna includes a radio frequency signal transmitter and a concave mirror, and the concave mirror reflects the test electromagnetic wave, and the receiving unit includes A horn antenna. The horn antenna receives the portion of the test electromagnetic wave that penetrates the material to be tested.

The second preferred embodiment of the electrical parameter measurement system of the present invention is similar to the first preferred embodiment, the main difference is that the radio wave anechoic chamber and the electromagnetic wave transceiver device of the second preferred embodiment form a far-field antenna volume测系统。 Measurement system. The transmitting unit includes a transmitting antenna electrically connected to the vector network analyzer, the receiving unit includes a receiving antenna electrically connected to the vector network analyzer, and the transmitting antenna transmits the test electromagnetic wave, and the transmitting antenna connects to the The distance between the material to be tested is the far field, so the test electromagnetic wave radiates from the transmitting antenna to the material to be tested as a uniform plane wave, and the shortest distance between the receiving antenna and the material to be tested is greater than the test A resonant wavelength of electromagnetic waves in free space.

The third preferred embodiment of the electrical parameter measurement system of the present invention is suitable for measuring electrical parameters of a material to be measured. The third preferred embodiment includes an electromagnetic wave transceiver device and a determination device.

The electromagnetic wave transceiving device includes a signal transceiving unit, a transmitting unit and a receiving unit.

The signal transceiving unit outputs a radio frequency test signal, the transmitting unit is electrically connected to the signal transceiving unit to receive the radio frequency test signal and converts it into a uniform plane wave test electromagnetic wave, and the transmitting unit radiates the test electromagnetic wave toward the material to be tested, The signal transceiving unit is further electrically connected to the receiving unit, and the signal transceiving unit further receives the portion of the test electromagnetic wave penetrating the material to be tested through the receiving unit.

The judging device is electrically connected to the signal transceiving unit, and constructs a measurement radiation pattern according to the portion of the test electromagnetic wave penetrating the material to be measured, and the judging device further stores a plurality of known materials to work at a radio frequency When the known materials correspond to multiple sets of known electrical parameters and multiple known radiation patterns, and each set of known electrical parameters corresponds to one of the known radiation patterns, the judgment The device further uses the difference between the measured radiation pattern and the known radiation patterns, and uses the known electrical parameters to determine a set of measured electrical parameters when the material to be tested operates at the radio frequency.

Preferably, each set of known electrical parameters includes a known dielectric constant and a known dielectric loss, and the determination device uses the measured radiation pattern to differentiate the directivity of the known radiation patterns. Determining the dielectric constant of the material under test when operating at the radio frequency, and using the difference in gain between the measured radiation pattern and the known radiation patterns to determine the dielectric constant of the material under test when operating at the radio frequency Dielectric loss.

Preferably, the third preferred embodiment further includes an electromagnetic wave anechoic chamber, and the electromagnetic wave transceiving device is disposed in the electromagnetic wave anechoic chamber. The electromagnetic wave anechoic chamber and the electromagnetic wave transceiving device form a shortened field antenna measurement system. The signal transceiving unit includes a vector network analyzer, the transmitter The unit includes a parabolic antenna. The parabolic antenna includes a radio frequency signal transmitter and a concave mirror, and the concave mirror reflects the test electromagnetic wave. The receiving unit includes a horn antenna. The horn antenna receives the test electromagnetic wave and penetrates the material to be tested. part.

The fourth preferred embodiment of the electrical parameter measurement system of the present invention is suitable for measuring the electrical parameters of a material to be measured. The fourth preferred embodiment includes an electromagnetic wave transceiver device and a determination device.

The electromagnetic wave transceiving device includes a signal transceiving unit, a transmitting unit and a receiving unit.

The signal transceiving unit outputs a radio frequency test signal, the transmitting unit is electrically connected to the signal transceiving unit to receive the radio frequency test signal and converts it into a uniform plane wave test electromagnetic wave, and the transmitting unit radiates the test electromagnetic wave toward the material to be tested, The signal transceiving unit is further electrically connected to the receiving unit, the signal transceiving unit further receives the portion of the test electromagnetic wave penetrating the material to be tested through the receiving unit, and measures a deviation of the test electromagnetic wave penetrating the material to be tested Shift frequency.

The judging device is electrically connected to the signal transceiving unit, and judges a dielectric constant of the material under test when operating at an RF frequency according to the difference between an initial frequency of the test electromagnetic wave radiated by the transmitting unit and the offset frequency .

The effect of the present invention is that the preferred embodiments use the test electromagnetic wave to penetrate the material to be measured to measure the dielectric constant and the dielectric loss of the material to be tested, so it can solve Disadvantages of manufacturing into a specific shape.

1‧‧‧ materials to be tested

2‧‧‧Electronic wave darkroom

3‧‧‧Electromagnetic wave transceiver

4‧‧‧judgment device

5‧‧‧Signal transceiver unit

51‧‧‧Vector Network Analyzer

6‧‧‧ Launch unit

61‧‧‧ Parabolic antenna

611‧‧‧RF signal transmitter

612‧‧‧Concave mirror

62‧‧‧Transmitting antenna

7‧‧‧Receiving unit

71‧‧‧Receiving antenna

FIG. 1 is a schematic diagram illustrating the first preferred embodiment and the third preferred embodiment of the electrical parameter measurement system of the present invention.

Fig. 2 is a schematic diagram of a second preferred embodiment and a fourth preferred embodiment of the present invention.

Referring to FIG. 1, an electrical parameter measurement system of the present invention is suitable for measuring electrical parameters of a material 1 to be tested. The first preferred embodiment of the electrical parameter measurement system includes an electric wave darkroom 2 and an electromagnetic wave transceiver装置3和一determination device 4.

The radio wave anechoic chamber 2 and the electromagnetic wave transceiving device 3 form a shortened field (Compact Antenna Test Ranges, CATR) antenna measurement system. The electromagnetic wave transceiving device 3 is installed in the radio wave anechoic chamber 2 and includes a signal transceiving unit 5. A transmitting unit 6 and a receiving unit 7.

The signal transceiving unit 5 outputs a radio frequency test signal. The signal transceiving unit 5 includes a vector network analyzer 51, and the vector network analyzer 51 outputs the radio frequency test signal.

The transmitting unit 6 is electrically connected to the signal transceiving unit 5 to receive the radio frequency test signal and converts it into a uniform plane wave test electromagnetic wave, and the transmitting unit 6 radiates the test electromagnetic wave toward the material to be tested 1 and the signal transceiving unit 5 The receiving unit 7 is electrically connected, and the signal transceiving unit 5 further receives the portion of the test electromagnetic wave penetrating the material to be tested 1 through the receiving unit 7.

In this embodiment, the transmitting unit 6 includes a parabolic antenna 61. The parabolic antenna 61 includes a radio frequency signal transmitter 611 implemented as a horn antenna, and a concave mirror 612, and the concave mirror 612 is used to reflect the test Electromagnetic wave; the receiving unit 7 is a horn antenna, used to receive the part of the test electromagnetic wave penetrating the material 1 to be tested.

The judging device 4 is electrically connected to the signal transceiving unit 5, and according to the test electromagnetic The part after the wave penetrates the material to be measured 1 to construct a measurement radiation pattern, and the difference between the measurement radiation pattern and a reference radiation pattern is used to determine when the material to be measured 1 operates at a radio frequency A set of measured electrical parameters.

In more detail, when the reference radiation field type is a free space between the transmitting unit 6 and the receiving unit 7, the judging device 4 is constructed according to the part of the test electromagnetic wave received by the receiving unit 7 And, the set of measured electrical parameters includes a dielectric constant and a dielectric loss when the material to be tested 1 operates at the radio frequency, the determination device 4 uses the measured radiation pattern and the reference radiation field The directivity difference of the type determines the dielectric constant, and the gain difference between the measured radiation pattern and the reference radiation pattern is used to determine the dielectric loss.

Supplementary note, the greater the difference in directivity angle between the measured radiation pattern and the reference radiation pattern, the greater the dielectric constant of the material to be tested 1 when operating at the RF frequency; when the measured radiation field The greater the difference in gain between the type and the reference radiation field type, the greater the dielectric loss when the material under test 1 operates at the radio frequency.

Referring to FIG. 2, the second preferred embodiment of the present invention is similar to the first preferred embodiment, the main difference is that the radio wave anechoic chamber 2 and the electromagnetic wave transceiver 3 of the second preferred embodiment form a far-field antenna Measurement system. The transmitting unit 6 includes a transmitting antenna 62 electrically connected to the vector network analyzer 51, the receiving unit 7 includes a receiving antenna 71 electrically connected to the vector network analyzer 51, and the transmitting antenna 62 transmits the test Electromagnetic waves, the distance between the transmitting antenna 62 and the material to be tested 1 is the far field, so the test electromagnetic waves radiated from the transmitting antenna 62 to the material to be tested 1 can be regarded as a uniform plane wave, and the receiving antenna 71 to The shortest distance between the material to be tested 1 is greater than a resonance wavelength of the test electromagnetic wave in free space.

Referring again to FIG. 1, the third preferred embodiment of the present invention and the first preferred embodiment Approximately, the main difference is that the judgment device 4 of the third preferred embodiment further prestores a plurality of known materials (not shown) when working at an RF frequency, the known materials correspond to multiple sets Known electrical parameters and multiple known radiation patterns, and each set of known electrical parameters corresponds to one of the known radiation patterns, the determination device 4 further uses the measured radiation pattern and the Knowing the difference in radiation pattern, and using the known electrical parameters to determine a set of measured electrical parameters when the material to be tested 1 works at the radio frequency. Similar to the first preferred embodiment, each set of known electrical parameters in the third preferred embodiment also includes a known dielectric constant and a known dielectric loss, the difference is that: the third The determination device 4 in the preferred embodiment uses the difference in directivity between the measured radiation pattern and the known radiation patterns to determine the dielectric constant of the material to be tested 1 when operating at the radio frequency, and uses The difference in gain between the measured radiation pattern and the known radiation patterns determines the dielectric loss when the material to be tested 1 operates at the radio frequency.

For example, when the gain of the measured radiation pattern is most similar to one of the gains of the known radiation patterns, the dielectric loss of the material under test 1 is closest to the known radiation pattern Corresponding to the dielectric loss of the known material, and when comparing the dielectric loss, the judging device 4 first judges the dielectric constant of the material to be tested 1, and then the material to be tested 1 The measured radiation field type gain is the same as the dielectric constant but the dielectric loss is different. 5 The gains of most known radiation field types are compared, and then the one with the closest gain is selected for the known material, then The dielectric loss of the selected known material is closest to the dielectric loss of the material to be tested 1, so the dielectric loss of the material to be tested 1 is known.

In addition, the radio wave anechoic chamber 2 and the electromagnetic wave transceiver 3 of the third preferred embodiment may constitute a shortened field antenna measurement system as shown in FIG. 1 or a far field antenna measurement system as shown in FIG. 2 .

2 again, the fourth preferred embodiment of the present invention is similar to the first preferred embodiment, the main difference is that the signal transceiving unit 5 of the fourth preferred embodiment further measures that the test electromagnetic wave penetrates the An offset frequency after the material 1 to be tested; the determining device 4 is electrically connected to the signal transceiving unit 5 and determines the difference according to the difference between an initial frequency of the test electromagnetic wave radiated by the transmitting unit 6 and the offset frequency A dielectric constant when the material to be tested 1 works at a radio frequency.

For example, when the material 1 to be tested is a material such as Styrofoam, whose dielectric constant is similar to that of free space, the offset frequency will be equal to the initial frequency of the test electromagnetic wave radiated by the transmitting unit 6, relative Ground, if the dielectric constant of the material to be measured 1 is higher, the value of the offset frequency will be smaller, so in practical applications only need to take a few known materials (different dielectric constants, approximate dielectric loss ) To measure the number of offset frequencies, and then measure the offset frequency of the material to be tested 1 in the same way, and compare the offset frequency of the material to be tested 1 with the known offset of the known materials By comparing the shift frequencies, the dielectric constant of the material to be measured 1 can be estimated by numerical methods such as interpolation.

In summary, the above preferred embodiments have the following advantages:

(1) In the first to third preferred embodiments, the electromagnetic wave transceiver device 3 emits the test electromagnetic wave to the material to be tested 1, and the judgment device 4 generates the test electromagnetic wave after penetrating the material to be tested 1 The directivity difference and gain difference of the measured radiation pattern are used to determine the dielectric constant and dielectric loss of the material 1 to be measured.

(2) The fourth preferred embodiment adopts a structure similar to the aforementioned first to third preferred embodiments, but the judging device 4 judges the difference based on the difference between the initial frequency and the offset frequency of the test electromagnetic wave The dielectric constant of the material 1 to be tested when operating at the radio frequency.

In summary, as described in points (1) and (2) above, these embodiments of the present invention do not require The test material 1 is manufactured in a specific shape to solve the problems of the prior art.

However, the above are only examples of the present invention, and should not be used to limit the scope of implementation of the present invention, any simple equivalent changes and modifications made in accordance with the scope of the patent application of the present invention and the content of the patent specification still belong to This invention covers the patent.

1‧‧‧ materials to be tested

2‧‧‧Electronic wave darkroom

3‧‧‧Electromagnetic wave transceiver

4‧‧‧judgment device

5‧‧‧Signal transceiver unit

51‧‧‧Vector Network Analyzer

6‧‧‧ Launch unit

61‧‧‧ Parabolic antenna

611‧‧‧RF signal transmitter

612‧‧‧Concave mirror

7‧‧‧Receiving unit

Claims (8)

An electrical parameter measurement system, suitable for measuring electrical parameters of a material to be tested, includes: an electromagnetic wave transceiver device, including a signal transceiver unit, a transmitting unit and a receiving unit, the signal transceiver unit outputs a radio frequency test Signal, the transmitting unit is electrically connected to the signal transceiving unit to receive the radio frequency test signal and is converted into a uniform plane wave test electromagnetic wave, and the transmitting unit radiates the test electromagnetic wave toward the material to be tested, and the signal transceiving unit is further electrically connected to the A receiving unit, the signal transceiving unit further receives the portion of the test electromagnetic wave penetrating the material to be tested through the receiving unit; and a judging device electrically connected to the signal transceiving unit and penetrating the material to be tested according to the test electromagnetic wave To construct a measurement radiation pattern, and use the difference between the measurement radiation pattern and a reference radiation pattern to determine a set of measurement electrical parameters when the material to be tested operates at a radio frequency. The reference radiation pattern is constructed when the transmitting unit and the receiving unit are in free space, and the judging device is constructed according to the portion of the test electromagnetic wave received by the receiving unit, and the set of electrical measurements The parameters include a dielectric constant (Dk) and a dielectric loss (Ds) when the material to be tested operates at the RF frequency, and the determination device uses the measured radiation pattern and the reference radiation The directivity difference of the field pattern is used to determine the dielectric constant, and the gain difference between the measured radiation pattern and the reference radiation pattern is used to determine the dielectric loss. The electrical parameter measurement system according to item 1 of the patent application scope further includes an electromagnetic wave dark room, and the electromagnetic wave transceiver device is disposed in the electromagnetic wave dark room, and the electromagnetic wave dark room and the electromagnetic wave transceiver device form a reduced field (Compact Antenna Test Ranges (CATR) antenna measurement system. The electrical parameter measurement system according to item 2 of the patent application scope, wherein the signal transceiving unit includes a vector network analyzer, the transmitting unit includes a parabolic antenna, and the parabolic antenna includes a radio frequency signal transmitter and a concave mirror, and The concave mirror reflects the test electromagnetic wave. The receiving unit includes a horn antenna. The horn antenna receives the portion of the test electromagnetic wave penetrating the material to be tested. The electrical parameter measurement system according to item 1 of the patent application scope, wherein the signal transceiving unit includes a vector network analyzer, the transmitting unit includes a transmitting antenna electrically connected to the vector network analyzer, and the receiving unit includes A receiving antenna electrically connected to the vector network analyzer, and the transmitting antenna transmits the test electromagnetic wave, and the distance between the transmitting antenna and the material to be measured is a far field. The electrical parameter measurement system according to item 1 of the patent application scope, wherein the signal transceiving unit includes a vector network analyzer, the transmitting unit includes a transmitting antenna electrically connected to the vector network analyzer, and the receiving unit includes A receiving antenna electrically connected to the vector network analyzer, and the transmitting antenna emits the test electromagnetic wave, the shortest distance between the receiving antenna and the material to be tested is greater than a resonance wavelength of the test electromagnetic wave in free space. An electrical parameter measurement system, suitable for measuring electrical parameters of a material to be tested, includes: an electromagnetic wave transceiver device, including a signal transceiver unit, a transmitting unit and a receiving unit, the signal transceiver unit outputs a radio frequency test Signal, the transmitting unit is electrically connected to the signal transceiving unit to receive the radio frequency test signal and is converted into a uniform plane wave test electromagnetic wave, and the transmitting unit radiates the test electromagnetic wave toward the material to be tested, and the signal transceiving unit is further electrically connected to the A receiving unit, the signal transceiving unit further receives the portion of the test electromagnetic wave penetrating the material to be tested through the receiving unit; and a judging device electrically connected to the signal transceiving unit and penetrating the material to be tested according to the test electromagnetic wave To construct a measurement radiation pattern, and the judgment device further pre-stores a plurality of known electrical parameters and multiple The radiation pattern is known, and each set of known electrical parameters corresponds to one of the known radiation patterns. The judgment device further uses the measured radiation pattern and the difference between the known radiation patterns and uses The known electrical parameters determine a set of measured electrical parameters when the material to be tested operates at the RF frequency, wherein each set of known electrical parameters includes a known dielectric constant and a known dielectric Electrical loss, the judging device uses the directivity difference between the measured radiation pattern and the known radiation patterns to determine the dielectric constant of the material under test when operating at the radio frequency, and uses the measured radiation field Type and such The gain difference of the radiation pattern is known to determine the dielectric loss when the material to be tested operates at the radio frequency. The electrical parameter measurement system according to item 6 of the patent application scope further includes: an electromagnetic wave dark room, and the electromagnetic wave transceiver device is disposed in the electromagnetic wave dark room, and the electromagnetic wave dark room and the electromagnetic wave transceiver device form a shortened field antenna Measurement system, the signal transceiving unit includes a vector network analyzer, the transmitting unit includes a parabolic antenna, the parabolic antenna includes a radio frequency signal transmitter and a concave mirror, and the concave mirror reflects the test electromagnetic wave, and the receiving unit includes a Horn antenna, which receives the part of the test electromagnetic wave after penetrating the material to be tested. An electrical parameter measurement system, suitable for measuring electrical parameters of a material to be tested, includes: an electromagnetic wave transceiver device, including a signal transceiver unit, a transmitting unit and a receiving unit, the signal transceiver unit outputs a radio frequency test Signal, the transmitting unit is electrically connected to the signal transceiving unit to receive the radio frequency test signal and is converted into a uniform plane wave test electromagnetic wave, and the transmitting unit radiates the test electromagnetic wave toward the material to be tested, and the signal transceiving unit is further electrically connected to the A receiving unit, the signal transceiving unit further receives the portion of the test electromagnetic wave penetrating the material to be tested through the receiving unit, and measures an offset frequency after the test electromagnetic wave penetrates the material to be tested; and A judging device, electrically connected to the signal transceiving unit, using the value of the offset frequency to compare with the known offset frequency of a plurality of known materials, and calculating the dielectric constant of the material to be measured by interpolation .

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