Antenna protection effectiveness testing system and method based on reciprocity principle

Abstract

The present invention proposes an antenna protection effectiveness test system and method based on the reciprocity principle, which belongs to the field of antenna testing technology. The present invention utilizes the reciprocity characteristics of the energy selective protection antenna to directly inject the microwave source signal into the energy selective protection antenna to be tested, gradually increases the power of the microwave source signal, receives the electromagnetic waves radiated by the energy selective protection antenna through the standard receiving antenna, and observes the changes in the radiation capability of the energy selective protection antenna. When the radiation capability of the energy selective protection antenna decreases, it means that the energy selective protection antenna enters a protection state. At this time, the accurate protection effectiveness can be calculated by comparing the radiation capability before and after. Since the antenna is a reciprocal device, the change in the receiving capability can be inferred by the change in the radiation capability, that is, the protection effectiveness of the energy selective protection antenna can be calculated.

Description

Technical Field

[0001] The present invention belongs to the technical field of antenna testing, and in particular relates to an antenna protection effectiveness testing system and method based on the reciprocity principle. Background Art

[0002] With the rapid development of wireless communication technology and the increasingly complex electromagnetic environment, electronic information equipment faces the threat of high-power microwave radiation fields. How to achieve electromagnetic protection for electronic information systems while ensuring their normal operation has become a pressing issue. Currently, energy domain protection methods for electronic information systems mainly include energy selective shields, ESPAs (Energy Selective Protective Antennas), and circuit-level energy selective protection devices. SE testing is a key step in verifying the protective capabilities of energy selective protection structures, and achieving accurate SE (Shielding Effectiveness) testing is crucial.

[0003] Energy-selective surface technology is an effective method for electromagnetic protection in RF front-ends. It can achieve spatially nonlinear transmission characteristics based on variations in incident wave field strength, achieving a transient adaptive protection effect that reflects strong fields but transmits weak fields. Traditional SE testing methods for energy-selective surfaces include irradiation and waveguide injection. These methods employ a high-power irradiation source or a high-power injection source, gradually increasing the input power to determine the relationship between input power and received power, thereby determining the SE of the energy-selective surface.

[0004] ESPA integrates protection and antenna functionality by adding nonlinear devices and designing the structure onto the existing antenna structure. Currently, similar to energy selective surface technology, SE testing for ESPA generally uses high-power irradiation.

[0005] For example, the high-power irradiation method is used to test ESPA. A high-power signal source is directly connected to a transmitting antenna to irradiate high-power microwaves. The antenna under test acts as a receiving antenna, receiving the irradiated electromagnetic waves. The received signal is attenuated by an attenuator and then detected by a peak envelope detector. Finally, an oscilloscope displays the detected voltage. During the experiment, the output power of the high-power signal source gradually increases, and the voltage change is detected by the oscilloscope to obtain the SE of the ESPA. However, the high-power irradiation method requires a high output power of the high-power signal source. Conventional high-power sources are difficult to create high-power irradiation field conditions under irradiation conditions. Therefore, this method has high experimental requirements and limited flexibility.

[0006] Another example is to connect a signal source directly to a power amplifier, which is then connected to one port of an isolator via a directional coupler. The isolator's second port is connected to the ESPA under test, and the third port is connected to an attenuator and finally to a spectrum analyzer. The signal source's output power is gradually increased, and the antenna's protection capability is evaluated by observing the reflected power of the ESPA under test, which is the input power of the spectrum analyzer. This method does not require a high-power signal source. However, it can only measure the reflection coefficient of the ESPA in its normal and protection states. While it can be used to simply evaluate the ESPA's protection capability, due to the lack of antenna-related information such as the radiation pattern and gain, it is impossible to accurately obtain SE using existing experimental data.

[0007] Therefore, in order to accurately obtain the SE of ESPA, simplify the experimental setting requirements, and improve the completeness of the experiment, a more operable and flexible ESPASE testing method is needed.

[0008] At present, there are two main methods for testing the protection capability of ESPA: direct irradiation with a high-power microwave source and reflection coefficient testing.

[0009] The high-power microwave source direct irradiation method is suitable for SE testing of energy-selective surfaces (ESPs). A high-power signal source is directly connected to a transmitting antenna to irradiate high-power microwaves, creating a high-power microwave irradiation environment. The ESPA under test acts as a receiving antenna to receive the irradiated electromagnetic waves. The received signal is attenuated by an attenuator and then detected by a peak envelope detector. The detected voltage is ultimately displayed on an oscilloscope. During the experiment, the output power of the high-power signal source is gradually increased. When the irradiation field intensity reaches the threshold that activates the ESPA's protective structure, the ESPA begins to produce its protective effect. The ESPA's SE is determined by the change in the detection voltage.

[0010] The reflection coefficient test method uses an isolator device. First, a signal source is directly connected to a power amplifier, which is then connected to one port of the isolator via a directional coupler. The second port of the isolator is connected to the ESPA under test, and the third port is connected to an attenuator and finally to a spectrum analyzer. The signal source output power is gradually increased, and the antenna's protection capability is evaluated by observing the reflected power of the ESPA under test, which is the input power of the spectrum analyzer.

[0011] The high-power microwave source direct irradiation method described above requires the generation of a high-power irradiation field. This places high demands on a high-power signal source or power amplifier, resulting in high experimental requirements and limited flexibility. The reflection coefficient test method, on the other hand, does not require a high-power signal source, but it only measures the reflection coefficient of the ESPA and lacks information such as the antenna's directivity pattern and gain, making it impossible to obtain accurate SE.

[0012] The direct irradiation method using a high-power microwave source has been widely accepted and recognized, but it places extremely high demands on experimental equipment, requiring a high-power microwave source or a power amplifier with excellent performance. It is impossible to set up this experimental scenario under conventional experimental conditions.

[0013] The reflection coefficient test method is a new test method that can simply evaluate protection capabilities by detecting changes in ESPA reflected power. It requires minimal experimental equipment and can be set up using conventional experimental conditions. However, this method cannot accurately determine the SE of ESPA due to the lack of antenna-related information such as antenna pattern and gain. Summary of the Invention

[0014] In order to solve the above technical problems, the present invention proposes an antenna protection effectiveness testing solution based on the reciprocity principle.

[0015] In a first aspect, the present invention provides an antenna protection effectiveness test system based on the reciprocity principle. The system includes a transmitting link and a receiving link. The transmitting link includes a microwave signal source, a power amplifier, an isolator, and an energy-selective protection antenna to be tested. The receiving link includes a standard receiving antenna, an attenuator, and a spectrum analyzer.

[0016] The energy selective protection antenna to be tested is used as the transmitting antenna, and the protection capability of the energy selective protection antenna to be tested is determined by observing the changes in the antenna's transmission performance. The energy selective protection antenna to be tested is a reciprocal microwave device, and its receiving performance and transmitting performance are analyzed equivalently to test its protection effectiveness.

[0017] In the transmission link, a microwave signal source generates a microwave signal, which is amplified by a power amplifier to generate a high-power microwave signal. The signal is then connected to the energy selective protection antenna to be measured after passing through an isolator. The isolator is used to protect the power amplifier and prevent the high-power signal reflected by the energy selective protection antenna to be measured from damaging the sensitive components in the power amplifier.

[0018] In the receiving link, a standard receiving antenna is used to receive the radiation signal of the energy selective protection antenna to be measured. The received signal is attenuated by an attenuator and connected to a spectrum analyzer, and the magnitude of the received signal is observed by the spectrum analyzer.

[0019] According to the system of the first aspect of the present invention, the system tests the protection effectiveness of the energy selective protection antenna to be tested, wherein: the microwave signal source generates a frequency of , power is The microwave signal falls within the working frequency band of the energy selective protection antenna to be measured; the microwave signal is amplified by the power amplifier, and the power amplifier is The gain at the frequency point is , the energy to be measured selects the protection antenna at The gain at the frequency point is , the loss in the transmitting link is ; The free space loss from the transmitting link to the receiving link is , the receiving antenna in the receiving link is The gain at the frequency point is , the attenuation coefficient of the attenuator is , the loss in the receiving link is The working frequency band of the standard receiving antenna covers the working frequency band of the energy selection protection antenna to be measured. The power of the signal received by the spectrum analyzer is ,but ; The values ​​are different in normal working state and protection state. and are variables, and the others are constants.

[0020] According to the system of the first aspect of the present invention, the system tests the protection effectiveness of the energy selective protection antenna to be tested, wherein:

[0021] Linearly increase the output power of the microwave signal source from small to large ;

[0022] When in the first range, The microwave signal is radiated normally by the protection antenna selected by the energy to be measured, and the received signal power and It increases linearly; as the output power increases, when the field strength at the feed port of the energy selective protection antenna to be measured increases to the first threshold, the protection structure is activated, and the gain of the energy selective protection antenna to be measured Decrease, received signal power Decrease, then the gain The degree of decrease is used as the protection effectiveness of the protection antenna selected as the energy to be measured;

[0023] along with Increase to the second range, the received signal power It returns to the original linear increase level, and the protection structure of the energy selection protection antenna to be measured has been damaged and has no protection capability.

[0024] According to the system of the first aspect of the present invention, the system tests the protection effectiveness of the energy selective protection antenna to be tested, wherein:

[0025] right and When the curve is analyzed, When the power starts to increase nonlinearly, the energy to be measured selects the injection power of the protection antenna as the protection structure startup threshold. When the power recovers to the original linear increase level, the injection power of the protection antenna selected by the energy to be measured is the maximum tolerable power threshold; the electric field distribution of the coaxial line Expressed as:

[0026]

[0027] Where V is the voltage between the inner and outer conductors, is the coaxial radius, and the range is , is the inner diameter, is the outer diameter, the injected power and coaxial line characteristic impedance They are:

[0028]

[0029]

[0030] in, is the dielectric constant of the dielectric part of the coaxial line;

[0031] The maximum field strength at the feeding location is for:

[0032]

[0033] According to the injection power Calculate the starting field strength and damage field strength of the protection structure at the feeding port.

[0034] A second aspect of the present invention provides a method for testing antenna protection effectiveness based on the reciprocity principle. The method comprises configuring a microwave signal source, a power amplifier, an isolator, and a test energy selection protection antenna on a transmitting link, and configuring a standard receiving antenna, an attenuator, and a spectrum analyzer on a receiving link. In the method:

[0035] The energy selective protection antenna to be tested is used as the transmitting antenna, and the protection capability of the energy selective protection antenna to be tested is determined by observing the changes in the antenna's transmission performance. The energy selective protection antenna to be tested is a reciprocal microwave device, and its receiving performance and transmitting performance are analyzed equivalently to test its protection effectiveness.

[0036] In the transmission link, a microwave signal source generates a microwave signal, which is amplified by a power amplifier to generate a high-power microwave signal. The signal is then connected to the energy selective protection antenna to be measured after passing through an isolator. The isolator is used to protect the power amplifier and prevent the high-power signal reflected by the energy selective protection antenna to be measured from damaging the sensitive components in the power amplifier.

[0037] In the receiving link, a standard receiving antenna is used to receive the radiation signal of the energy selective protection antenna to be measured. The received signal is attenuated by an attenuator and connected to a spectrum analyzer, and the magnitude of the received signal is observed by the spectrum analyzer.

[0038] According to the method of the second aspect of the present invention, the protection effectiveness of the energy selective protection antenna to be tested is tested, specifically comprising: generating a microwave signal source with a frequency of , power is The microwave signal falls within the working frequency band of the energy selective protection antenna to be measured; the microwave signal is amplified by the power amplifier, and the power amplifier is The gain at the frequency point is , the energy to be measured selects the protection antenna at The gain at the frequency point is , the loss in the transmitting link is ; The free space loss from the transmitting link to the receiving link is , the receiving antenna in the receiving link is The gain at the frequency point is , the attenuation coefficient of the attenuator is , the loss in the receiving link is The working frequency band of the standard receiving antenna covers the working frequency band of the energy selection protection antenna to be measured. The power of the signal received by the spectrum analyzer is ,but ; The values ​​are different in normal working state and protection state. and are variables, and the others are constants.

[0039] According to the method of the second aspect of the present invention, the protection effectiveness of the energy selective protection antenna to be tested is tested, specifically comprising:

[0040] Linearly increase the output power of the microwave signal source from small to large ;

[0041] When in the first range, The microwave signal is radiated normally by the protection antenna selected by the energy to be measured, and the received signal power and It increases linearly; as the output power increases, when the field strength at the feed port of the energy selective protection antenna to be measured increases to the first threshold, the protection structure is activated, and the gain of the energy selective protection antenna to be measured Decrease, received signal power Decrease, then the gain The degree of decrease is used as the protection effectiveness of the protection antenna selected as the energy to be measured;

[0042] along with Increase to the second range, the received signal power It returns to the original linear increase level, and the protection structure of the energy selection protection antenna to be measured has been damaged and has no protection capability.

[0043] According to the method of the second aspect of the present invention, the protection effectiveness of the energy selective protection antenna to be tested is tested, specifically comprising:

[0044] right and When the curve is analyzed, When the power starts to increase nonlinearly, the energy to be measured selects the injection power of the protection antenna as the protection structure startup threshold. When the power recovers to the original linear increase level, the injection power of the protection antenna selected by the energy to be measured is the maximum tolerable power threshold; the electric field distribution of the coaxial line Expressed as:

[0045]

[0046] Where V is the voltage between the inner and outer conductors, is the coaxial radius, and the range is , is the inner diameter, is the outer diameter, the injected power and coaxial line characteristic impedance They are:

[0047]

[0048]

[0049] in, is the dielectric constant of the dielectric part of the coaxial line;

[0050] The maximum field strength at the feeding location is for:

[0051]

[0052] According to the injection power Calculate the starting field strength and damage field strength of the protection structure at the feeding port.

[0053] Based on the testing needs and practical applications of antenna SE, this invention proposes a system and method for testing antenna protection effectiveness based on the reciprocity principle. This invention primarily utilizes the reciprocity property of energy-selective protection antennas. A microwave source signal is directly injected into the ESPA to be tested. The microwave source signal's power is gradually increased, and the electromagnetic waves radiated by the ESPA are received by a standard receiving antenna. Changes in the ESPA's radiation capacity are observed. When the ESPA's radiation capacity decreases, it indicates that the ESPA has entered a protective state. At this point, the accurate SE can be calculated by comparing the radiation capacity before and after. Because the antenna is a reciprocal device, changes in radiation capacity can be inferred from changes in receiving capacity, thereby calculating the ESPA's SE. Traditional high-power microwave source direct irradiation methods require high experimental equipment conditions, while reflection coefficient measurement methods cannot accurately obtain SE. However, the method designed in this application requires less experimental equipment and is relatively simple to conduct. It does not require a high-power microwave signal source, but only requires a standard microwave signal source and a power amplifier. Furthermore, this method can directly measure accurate SE without complex mathematical calculations. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0055] Figure 1 This is the structural diagram of the antenna protection effectiveness test system based on the reciprocity principle.

[0056] Figure 2 Schematic diagram of the measured results of the protection effectiveness of the energy-selective protection antenna. DETAILED DESCRIPTION

[0057] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0058] Definitions of Abbreviations and Key Terms:

[0059] ESPA: Energy Selective Protective Antenna, energy selective protection antenna, mainly for protection against high-power microwaves.

[0060] SE: Shielding Effectiveness, refers to the protection antenna's ability to suppress high-power microwave radiation relative to its original gain reception.

[0061] Existing electronic information systems urgently need to address electromagnetic hardening issues, enhance electromagnetic protection capabilities, and mitigate the threat posed by high-power microwaves to electronic information equipment. SE (Separation Emission) (SE) is a key metric for evaluating the electromagnetic protection capabilities of ESPAs, and SE of electronic information equipment is typically determined through experimental testing. Traditional methods using direct irradiation with high-power microwave sources require high experimental equipment requirements and lack flexibility. The reflection coefficient test method, which evaluates protection capabilities by comparing the reflection coefficient of an ESPA in normal and protective conditions, only measures the reflection coefficient and cannot accurately determine SE.

[0062] To this end, the present invention proposes a convenient SE testing system and method for ESPA based on the experimental testing requirements of the SE.

[0063] First embodiment

[0064] This embodiment relates to a SE test system and method for an energy selective protection antenna. It is based on the reciprocity characteristic of the antenna itself. By directly injecting a high-power microwave signal into the ESPA and observing the change in the ESPA's radiation capability, the change in the ESPA's receiving capability under high-power microwave signal irradiation is deduced, that is, the SE of the ESPA is obtained. Figure 1 As shown in FIG, the test system includes a transmitting link and a receiving link. The transmitting link includes a microwave signal source, a power amplifier, an isolator, and an ESPA to be tested. The receiving link includes a standard receiving antenna, an attenuator, and a spectrum analyzer.

[0065] The traditional high-power microwave source direct irradiation method uses the ESPA under test as a receiving antenna and evaluates the ESPA's protective capability by observing changes in its receiving performance. The experimental system in this application differs from the traditional method in that it uses the ESPA under test as a transmitting antenna and infers the ESPA's protective capability by observing changes in its transmitting performance. Because the antenna is a reciprocal microwave device, its receiving and transmitting performance can be analyzed equivalently. Therefore, this application method is effective for testing the SE of an ESPA.

[0066] In the transmission chain, a microwave signal is first generated by a microwave signal source, amplified by a power amplifier to produce a high-power microwave signal, connected to an isolator, and finally to the ESPA under test. The isolator protects the power amplifier, preventing the high-power signal reflected by the ESPA under test from damaging sensitive components within the power amplifier.

[0067] In the receiving link, a standard receiving antenna is used to receive the radiation signal of the ESPA under test. The received signal is attenuated by an attenuator and then connected to a spectrum analyzer. The magnitude of the received signal is observed by the spectrum analyzer.

[0068] The microwave signal source generates a frequency of , the power is The microwave signal falls within the working frequency band of the ESPA to be tested. The microwave signal is amplified by the power amplifier. The gain at the frequency point is , the ESPA to be tested is The gain at the frequency point is , the loss in the transmitting link is The free space loss from the transmitting link to the receiving link is , the receiving antenna in the receiving link is The gain at the frequency point is , the attenuation coefficient of the attenuator is , the loss in the receiving link is During the experimental setup, the operating frequency band of the standard receiving antenna should cover the operating frequency band of the ESPA to be tested, and the gain should be clearly determined.

[0069] Therefore, by calculation, we can get the power of the signal received by the spectrum analyzer: size:

[0070]

[0071] In the above formula, since ESPA is a protective antenna, its gain is It is different in normal working state and protection state. In summary, and is a variable, and the other parameters are constants.

[0072] During the experiment, first connect all the experimental equipment according to the experimental plan proposed in the application. Then, linearly increase the output power of the microwave signal source from small to large. .at first, Smaller, Microwave signals can be radiated normally through ESPA, and the received signal power and When the output power increases to a certain level, the field strength at the ESPA feed port is large enough to cause the protection structure to start, and the gain of ESPA The received signal power has decreased The degree of gain reduction is the SE of ESPA. When the received signal power It may return to the original linear increase level. At this time, the protective structure of the ESPA antenna has been damaged and has no protective capability. In summary, the solution of the present invention uses the conversion method to cleverly convert the change of ESPA radiation capability into the received signal power. To characterize, according to The change in can effectively determine the SE of ESPA. This experiment has high reliability and requires minimal experimental equipment, making it easy to perform in the laboratory.

[0073] right and When the curve is analyzed, When the power starts to increase nonlinearly, the ESPA injection power at this time is the protection structure activation threshold. When the power returns to its original linear increase level, the ESPA injection power at this time is the maximum tolerable power threshold.

[0074] In addition, the electric field distribution formula of the coaxial line is as follows:

[0075]

[0076] V is the voltage between the inner conductor and the outer conductor, Is a variable, indicating the coaxial radius, ranging from , represent the inner diameter and outer diameter respectively, and the input power and coaxial line characteristic impedance The size of is as follows:

[0077]

[0078]

[0079] in, is the dielectric constant of the coaxial cable dielectric part.

[0080] Combining the above formulas, we can get the maximum field strength at the feeding position: Size:

[0081]

[0082] It can be seen that according to the injection power The starting field strength and damage field strength of the protection structure at the feeding port can be calculated.

[0083] Second Example (SE Test of Patch-Type ESPA)

[0084] The patch-type ESPA has a metal radiating patch structure on the front and a ground plane on the back. The feed port uses an SMA connector and is soldered to the ground plane. The internal feed probe penetrates the dielectric substrate and connects to the radiating patch for power supply.

[0085] Based on the internal protective structure of the ESPA feed structure, the existing patch antenna feed structure was modified and loaded with diodes, completing the ESPA design with energy-selective electromagnetic protection. This type of antenna is a coaxially fed patch antenna, and the existing structure lacked sufficient space to integrate energy-selective electromagnetic protection. Therefore, a method was adopted whereby the antenna dielectric substrates were layered, with the center of the upper dielectric substrate hollowed out. A protective structure was designed at the coaxial probe structure to achieve this protection. The upper and lower dielectric substrates were then pressed together and secured at the end points with Nylon screws. Furthermore, the hollowed-out portion of the dielectric substrate provided sufficient height to protect the diode, preventing damage from the mechanical stress of the laminated layers.

[0086] like Figure 2 Figure 2 shows the SE experimental test results for a patch-type ESPA. First, the experimental equipment for the experimental plan should be carefully selected. A microwave signal source should be selected with a wide adjustable output signal power range and a wide frequency band, and its maximum output power should be above 20 dBm. A power amplifier should be selected with high gain and a stable amplification factor. Before the experiment begins, the amplification factor of the power amplifier should be tested at the operating frequency through relevant experiments. The isolation of the isolator should be above 20 dB to ensure the safety and stability of sensitive components within the power amplifier. The operating frequency band of the standard receiving antenna should cover the actual operating frequency band of the ESPA. The operating frequency band of the spectrum analyzer should also cover the actual operating frequency band of the ESPA.

[0087] After the experimental system is set up, gradually increase the output power of the microwave signal source (that is, increase the injection power of the ESPA) and observe the received power of the spectrum analyzer in the receiving link. By converting the injected power to the received power, a curve is obtained, which can be used to analyze the ESPA's SE.

[0088] First, the injected power is gradually increased from -10 dBm. The received power increases linearly with the injection power. At this point, the antenna is operating normally, and the injected signal is radiated normally into free space. When the injected power reaches 22 dBm, the received power no longer increases linearly with the injection power. At this point, the protective structure has activated, and the antenna's radiation capability is weakened. The degree of reduction in the antenna gain coefficient is the SE, which is the difference between the linear output power and the actual output power. When the injected power reaches 48 dBm, the received power returns to its original linearly increasing power level. At this point, the high field strength at the feed port has damaged the protective structure, and the ESPA no longer provides protection.

[0089] It can be seen that the activation threshold of the protection structure of this type of ESPA is 22 dBm, the damage threshold is 48 dBm, and the maximum protection effectiveness can reach 26 dB.

[0090] In summary, compared to the prior art, the present invention avoids the need for a high-power microwave source and a high-gain power amplifier required by conventional irradiation methods, eliminating the need for bulky high-power microwave sources or power amplifiers. The experimental method designed in the present invention is simple, highly operational, and low-cost. Furthermore, the present invention avoids the drawback of the reflection coefficient test method, which only measures the reflection coefficient of the ESPA under different operating conditions. The experimental data obtained by the experimental system of the present invention already includes information such as antenna patterns and gain, allowing accurate SE data to be derived, resulting in more accurate experimental results.

[0091] Please note that the technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. The above embodiments only express several implementation methods of the present application. The description is relatively specific and detailed, but it cannot be understood as a limitation on the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of this application, several variations and improvements can be made, which all fall within the scope of protection of this application. Therefore, the scope of protection of the patent in this application shall be based on the attached claims.

Claims

1. An antenna protection effectiveness test system based on the reciprocity principle, characterized in that: The system includes a transmitting link and a receiving link. The transmitting link includes a microwave signal source, a power amplifier, an isolator, and a protection antenna for selecting energy to be measured. The receiving link includes a standard receiving antenna, an attenuator, and a spectrum analyzer. The energy selective protection antenna to be tested is used as the transmitting antenna, and the protection capability of the energy selective protection antenna to be tested is determined by observing the changes in the antenna's transmission performance. The energy selective protection antenna to be tested is a reciprocal microwave device, and its receiving performance and transmitting performance are analyzed equivalently to test its protection effectiveness. In the transmission link, a microwave signal source generates a microwave signal, which is amplified by a power amplifier to generate a high-power microwave signal. The signal is then connected to the energy selective protection antenna to be measured after passing through an isolator. The isolator is used to protect the power amplifier and prevent the high-power signal reflected by the energy selective protection antenna to be measured from damaging the sensitive components in the power amplifier. In the receiving link, a standard receiving antenna is used to receive the radiation signal from the energy selective protection antenna to be measured. The received signal is attenuated by an attenuator and connected to a spectrum analyzer, where the magnitude of the received signal is observed. The system tests the protection effectiveness of the energy selective protection antenna to be tested, wherein: the microwave signal source generates a frequency of , power is The microwave signal falls within the working frequency band of the energy selective protection antenna to be measured; the microwave signal is amplified by the power amplifier, and the power amplifier is The gain at the frequency point is , the energy to be measured selects the protection antenna at The gain at the frequency point is , the loss in the transmitting link is ; The free space loss from the transmitting link to the receiving link is , the receiving antenna in the receiving link is The gain at the frequency point is , the attenuation coefficient of the attenuator is , the loss in the receiving link is The working frequency band of the standard receiving antenna covers the working frequency band of the energy selection protection antenna to be measured. The power of the signal received by the spectrum analyzer is ,but ; The values ​​are different in normal working state and protection state. and are variables, and the others are constants.

2. The antenna protection effectiveness testing system based on the reciprocity principle according to claim 1, characterized in that: The system tests the protection effectiveness of the energy selective protection antenna to be tested, wherein: Linearly increase the output power of the microwave signal source from small to large ; When in the first range, The microwave signal is radiated normally by the protection antenna selected by the energy to be measured, and the received signal power and It increases linearly; as the output power increases, when the field strength at the feed port of the energy selective protection antenna to be measured increases to the first threshold, the protection structure is activated, and the gain of the energy selective protection antenna to be measured Decrease, received signal power Decrease, then the gain The degree of decrease is used as the protection effectiveness of the protection antenna selected as the energy to be measured; along with Increase to the second range, the received signal power It returns to the original linear increase level, and the protection structure of the energy selection protection antenna to be measured has been damaged and has no protection capability.

3. The antenna protection effectiveness testing system based on the reciprocity principle according to claim 2, characterized in that: The system tests the protection effectiveness of the energy selective protection antenna to be tested, wherein: right and When the curve is analyzed, When the power starts to increase nonlinearly, the energy to be measured selects the injection power of the protection antenna as the protection structure startup threshold. When the power recovers to its original linear increase level, the injection power of the protection antenna selected by the energy to be measured is the maximum tolerable power threshold; the electric field distribution of the coaxial line Expressed as: ， Where V is the voltage between the inner and outer conductors, is the coaxial radius, and the range is , is the inner diameter, is the outer diameter, the injected power and coaxial line characteristic impedance They are: , ， in, is the dielectric constant of the coaxial medium; then the maximum field strength at the feeding position for: ， According to the injection power Calculate the starting field strength and damage field strength of the protection structure at the feeding port.

4. A method for testing antenna protection effectiveness based on the reciprocity principle, characterized in that: The method configures a microwave signal source, a power amplifier, an isolator, and a protection antenna for selecting energy to be measured on a transmission link, and configures a standard receiving antenna, an attenuator, and a spectrum analyzer on a receiving link; in the method: The energy selective protection antenna to be tested is used as the transmitting antenna, and the protection capability of the energy selective protection antenna to be tested is determined by observing the changes in the antenna's transmission performance. The energy selective protection antenna to be tested is a reciprocal microwave device, and its receiving performance and transmitting performance are analyzed equivalently to test its protection effectiveness. In the transmission link, a microwave signal source generates a microwave signal, which is amplified by a power amplifier to generate a high-power microwave signal. The signal is then connected to the energy selective protection antenna to be measured after passing through an isolator. The isolator is used to protect the power amplifier and prevent the high-power signal reflected by the energy selective protection antenna to be measured from damaging the sensitive components in the power amplifier. In the receiving link, a standard receiving antenna is used to receive the radiation signal from the energy selective protection antenna to be measured. The received signal is attenuated by an attenuator and connected to a spectrum analyzer, where the magnitude of the received signal is observed. Among them, the protection effectiveness of the energy selective protection antenna to be tested is tested, specifically including: the microwave signal source generates a frequency of , power is The microwave signal falls within the working frequency band of the energy selective protection antenna to be measured; the microwave signal is amplified by the power amplifier, and the power amplifier is The gain at the frequency point is , the energy to be measured selects the protection antenna at The gain at the frequency point is , the loss in the transmitting link is ; The free space loss from the transmitting link to the receiving link is , the receiving antenna in the receiving link is The gain at the frequency point is , the attenuation coefficient of the attenuator is , the loss in the receiving link is The working frequency band of the standard receiving antenna covers the working frequency band of the energy selection protection antenna to be measured. The power of the signal received by the spectrum analyzer is ,but ; The values ​​are different in normal working state and protection state. and are variables, and the others are constants.

5. The antenna protection effectiveness testing method based on the reciprocity principle according to claim 4, characterized in that: The protection effectiveness of the energy selective protection antenna to be tested is tested, including: Linearly increase the output power of the microwave signal source from small to large ; When in the first range, The microwave signal is radiated normally by the protection antenna selected by the energy to be measured, and the received signal power and It increases linearly; as the output power increases, when the field strength at the feed port of the energy selective protection antenna to be measured increases to the first threshold, the protection structure is activated, and the gain of the energy selective protection antenna to be measured Decrease, received signal power Decrease, then the gain The degree of decrease is used as the protection effectiveness of the protection antenna selected as the energy to be measured; along with Increase to the second range, the received signal power It returns to the original linear increase level, and the protection structure of the energy selection protection antenna to be measured has been damaged and has no protection capability.

6. The antenna protection effectiveness testing method based on the reciprocity principle according to claim 5, characterized in that: The protection effectiveness of the energy selective protection antenna to be tested is tested, including: right and When the curve is analyzed, When the power starts to increase nonlinearly, the energy to be measured selects the injection power of the protection antenna as the protection structure startup threshold. When the power recovers to its original linear increase level, the injection power of the protection antenna selected by the energy to be measured is the maximum tolerable power threshold; the electric field distribution of the coaxial line Expressed as: ， Where V is the voltage between the inner and outer conductors, is the coaxial radius, and the range is , is the inner diameter, is the outer diameter, the injected power and coaxial line characteristic impedance They are: , ， in, is the dielectric constant of the coaxial medium; then the maximum field strength at the feeding position for: ， According to the injection power Calculate the starting field strength and damage field strength of the protection structure at the feeding port.

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