Conduction safety margin test evaluation method for communication equipment with antenna tuning structure

Abstract

A conduction safety margin test evaluation method for communication equipment with an antenna tuning structure relates to the technical field of electromagnetic compatibility test, and specifically comprises the following steps: S1, the communication equipment autonomously selects a working frequency; s2, selecting a signal source of a proper model as simulation equipment according to the working frequency, adopting an antenna consistent with the model of the accompanying test communication equipment as a radiation antenna, disconnecting the tested communication equipment and the accompanying test communication equipment under the condition of ensuring a far field, simulating a communication signal of the accompanying test communication equipment through a method of loading the radiation antenna by the signal source, establishing a normal connection working state between the analog signal and the tested communication equipment; s3, loading an audio analyzer or an error detector at the tested equipment end; s4, carrying out a conduction safety margin test according to a conduction safety margin test method specified in the standard; according to the invention, the audio analyzer or the bit-error tester is adopted, so that the accuracy, repeatability and test efficiency of test results are improved under the condition that human subjective factors are reduced to the greatest extent.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic compatibility testing technology, and in particular to a method for conducting safety margin test evaluation of communication equipment with antenna adjustment structure. Background Technology

[0002] As the central nervous system for information transmission and detection, communication equipment integrates an increasing number of frequency-using devices on its platform. Simultaneously, advancements in electronic technology have led to continuously increasing integration and informatization levels of these devices, resulting in increasingly stringent requirements for electromagnetic compatibility (EMC) performance indicators. Countries like the US and UK have established relatively scientific and comprehensive testing standards and evaluation systems. US military standards MIL-STD-464C and MIL-STD-461F respectively specify EMC requirements at the system and equipment levels. The UK has proposed the STAN-59-411 series of standards for system and equipment-level EMC testing. In contrast, China's EMC field developed later. GJB151, "Electromagnetic Emission and Susceptibility Requirements for Military Equipment and Subsystems," was promulgated in 1986, upgraded to GJB151A in 1997, GJB151B in 2013, and will be upgraded to GJB151C in 2024. GJB1389 "System Electromagnetic Compatibility Requirements" was promulgated in 1992, upgraded to GJB1389A in 2005, upgraded to GJB1389B in 2022, and GJB8848-2016 "System Electromagnetic Environment Effect Test Methods" was promulgated in 2016.

[0003] GJB1389B-2022 and GJB8848-2016 are both top-level test method standards and do not explicitly specify test methods for communication equipment with specific antennas or structures. An antenna tuner, also known as an "antenna tuner," is an impedance matching network connecting the transmitter and transmitting antenna of a communication device. It enables impedance matching between the transmitter and transmitting antenna, allowing the transmitting antenna to radiate maximum power at its operating frequency. Antenna tuners play a crucial role in VHF, HF, and MHF / LF communications and are widely used. In radios used on various platforms such as individual soldiers, vehicles, and airborne devices, the "antenna tuner" is generally composed of inductors and capacitors. One end is the signal source end, connected to the transmitter end, and the other end is the load end, connected to the transmitting antenna end. From the basic principle, the antenna tuner has two functions: first, to compensate the entire load end, which is not in a resonant state, to resonate through series and parallel inductors and capacitors; second, if the input impedance of the load end is not equal to the output impedance of the signal source end after resonance, the transformer ratio between the load end and the signal source end is adjusted by changing the transmission coefficient of the network to achieve matching.

[0004] For the conducted safety margin test evaluation of communication equipment with antenna tuning structures, there are currently four main test methods: the actual communication method, the broadband antenna method, the injection method, and the integrated test instrument method. The actual communication method refers to conducting performance tests on communication equipment with antenna tuning structure in simulated actual working conditions. Based on the key performance indicators such as equipment power and communication distance, the tested equipment and the auxiliary equipment are arranged in two different locations. By adjusting the power and distance, the equipment is brought to operate at the critical state. After further adjustments, the safety margin test can be carried out. The advantages of this method are: 1) The test assessment is more consistent with the actual application scenario, and the test is conducted exactly as the equipment is used; 2) The test setup is relatively convenient, and there is no need to change the tested equipment and the auxiliary equipment. The disadvantages are: During the test, the test equipment is subject to many uncontrollable factors such as weather and surrounding environment. The impact of these uncontrollable factors on the test results is difficult to estimate, and it is necessary to avoid introducing uncontrollable factors as much as possible.

[0005] The broadband antenna method refers to replacing the antenna tuning structure and transmitting antenna in the device under test (DUT). Because the antenna is broadband, its impedance characteristics at different frequencies generally meet the transmission requirements. The DUT and the auxiliary device are placed in two different locations. By adding attenuators to bring the equipment to a critical state, further adjustments to the attenuators allow for safety margin testing. The advantages of this method are: 1) Unlike actual communication methods, this method, due to the addition of attenuators, allows the DUT and auxiliary devices to be placed at a closer distance, making testing more convenient; 2) The test results are less affected by weather and environment, facilitating result evaluation. The disadvantages are: 1) The equipment itself may not be directly suitable for this method, potentially requiring changes to internal settings. Furthermore, DUTs from different manufacturers may not all be suitable for this method, thus limiting its applicability; 2) The impedance characteristics of the broadband antenna at different frequencies have some error, affecting the test results; 3) The test process only assesses the performance parameters of the DUT, without evaluating the antenna tuning structure and transmitting antenna, resulting in an incomplete assessment.

[0006] The injection method refers to the direct interconnection of the device under test (DUT) and the auxiliary device via an RF cable, bypassing the transmitting and receiving antennas and the antenna tuning structure. The test state is adjusted by adding attenuators to the interconnection link. The advantages of this method are: 1) The test devices are relatively close, and the test is largely unaffected by natural environmental and human factors, resulting in good repeatability. The disadvantages are: 1) Generally, the internal software settings of the device need to be modified, altering the software configuration of the DUT; 2) The test only assesses the performance parameters of the DUT, without evaluating the antenna tuning structure and transmitting antenna, leading to an incomplete assessment.

[0007] The integrated test instrument method refers to constructing a separate loop by adding a coupling network, attenuator, integrated test instrument, and receiving equipment after the transmitter at the device under test (DUT). The DUT's performance parameters are tested by transmitting and receiving signals within this loop. The advantages of this method are: 1) It can bypass the antenna tuning structure and antenna, and no auxiliary equipment is needed during the test; 2) There are fewer uncontrollable factors during the test. The disadvantages are: 1) Communication is not established between the DUT and the auxiliary equipment during the test, and the internal hardware structure of the DUT is altered to some extent; 2) The test only assesses the DUT's performance parameters, without evaluating the antenna tuning structure and transmitting antenna, resulting in an incomplete assessment; 3) Because fixed-frequency testing is used, different frequencies need to be selected in different frequency bands for testing, increasing the workload. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for testing and evaluating the conduction safety margin of communication equipment with antenna adjustment structure.

[0009] The technical solution adopted in this invention is: A method for conducting safety margin test evaluation of communication equipment with antenna adjustment structure, specifically including the following steps: S1. Communication equipment can autonomously select its operating frequency: The test communication device and the companion communication device were powered on and placed in an open test area with low and stable background noise. The surrounding electromagnetic environment was detected and analyzed by the receiver to prevent interference signals from affecting the normal operation of the equipment. The far-field conditions were calculated according to the antenna type and operating frequency of the equipment to ensure that the test communication device and the companion communication device were in the far-field communication simulation of the actual communication conditions. Then the test communication device and the companion communication device were powered on and operated normally. Both were set to the autonomous frequency selection mode. The two devices selected the operating frequency suitable for the current external electromagnetic environment conditions through autonomous frequency selection and recorded the current operating frequency. S2. Signal simulation method based on a signal source loaded with a radiating antenna: Select a suitable signal source as the simulation device according to the operating frequency, and use an antenna of the same model as the test communication device as the radiating antenna. Under the condition of ensuring the far field, disconnect the test communication device and the test communication device, and simulate the communication signal of the test communication device by loading the radiating antenna with the signal source, and establish a normal connection and working state between the simulated signal and the test communication device. S3. Load an audio analyzer or bit error rate tester onto the device under test; S4. Conduct the conduction safety margin test according to the conduction safety margin test method specified in the standard, and ensure that the audio analyzer or bit error rate tester is within the range specified in the appropriate test outline during the test.

[0010] The method for conducting safety margin test evaluation of communication equipment with antenna adjustment structure, specifically the method of loading an audio analyzer or bit error rate tester at the end of the tested equipment in step S3, is as follows: Depending on the receiving port type of the communication device under test, load an audio analyzer or bit error rate tester onto the audio or digital port. During the loading process, try not to change the structure and internal circuitry of the device under test. If it is necessary to change the structure or internal circuitry of the device under test, the impact of the operation on the conducted safety margin test results of the device must be accurately assessed. If there is no impact or the impact is small, this method can be used. If there is a need for different frequencies, return to step S1.

[0011] Due to the adoption of the technical solution described above, the present invention has the following advantages: The conducted safety margin test evaluation method for communication equipment with antenna tuning structure described in this invention selects a frequency in an autonomous frequency selection mode for both the tested and auxiliary communication equipment. A directional radiating antenna loaded with a signal source is used instead of the auxiliary communication equipment. Simultaneously, an audio analyzer or bit error rate tester is connected to the tested equipment to monitor its status in real time. Compared with traditional conducted safety margin test methods of this type, the use of an audio analyzer or bit error rate tester improves upon the previous subjective voice evaluation method. While minimizing human subjective factors, it further improves the accuracy, repeatability, and efficiency of the test results. In this invention, the tested and auxiliary equipment are placed at close range, simulating the actual usage scenario of the communication equipment as closely as possible. The test repeatability is good, and the test results are largely unaffected by natural environment and human factors. The test frequency is autonomously selected by the tested and auxiliary equipment based on the external electromagnetic environment, reducing human intervention. Attached Figure Description

[0012] Figure 1 This is a diagram showing the setup for a traditional practical communication method experiment.

[0013] Figure 2 This is a test setup diagram for the traditional broadband antenna method.

[0014] Figure 3 This is a test setup diagram for the traditional injection method.

[0015] Figure 4 This is a test setup diagram for traditional integrated testing instruments.

[0016] Figure 5 This is a test setup diagram of the device under test in the test evaluation method adopted in this invention.

[0017] Figure 6 This is a flowchart of the experimental process of the present invention. Detailed Implementation

[0018] The present invention will be further explained and described below with reference to the accompanying drawings and embodiments. However, this should not be construed as limiting the scope of protection of the present invention. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention.

[0019] Combined with appendix Figure 5-6 The aforementioned method for testing and evaluating the conduction safety margin of communication equipment with antenna adjustment structure specifically includes the following steps: S1. Communication equipment can autonomously select its operating frequency: The test communication device and the companion communication device were powered on and placed in an open test area with low and stable background noise. The surrounding electromagnetic environment was detected and analyzed by the receiver to prevent interference signals from affecting the normal operation of the equipment. The far-field conditions were calculated according to the antenna type and operating frequency of the equipment to ensure that the test communication device and the companion communication device were in the far-field communication simulation of the actual communication conditions. Then the test communication device and the companion communication device were powered on and operated normally. Both were set to the autonomous frequency selection mode. The two devices selected the operating frequency suitable for the current external electromagnetic environment conditions through autonomous frequency selection and recorded the current operating frequency. The antenna type is an HRS33A complex log-periodic antenna; the operating frequency is 1.5 GHz. Far-field condition R≥2D 2 / λ, where R is the distance, D is the maximum size of the antenna, and λ is the wavelength; S2. Signal simulation method based on a signal source loaded with a radiating antenna: Select a suitable signal source model as the simulation device according to the operating frequency, and use an antenna model consistent with the test communication device as the radiating antenna. Under the condition of ensuring the far field, disconnect the test communication device and the test communication device, and simulate the communication signal of the test communication device by loading the radiating antenna with the signal source to establish a normal connection and working state between the simulated signal and the test communication device; the signal source is SMB 100A. S3. Load an audio analyzer or bit error rate tester onto the device under test: Depending on the receiving port type of the communication device under test, load an audio analyzer or bit error rate tester onto the audio or digital port. During loading, minimize alterations to the device's structure and internal circuitry. If alterations are necessary, accurately assess the impact of the operation on the device's conducted safety margin test results. If there is no impact or a minor impact, this method can be used. If different frequencies are required, return to step S1. The audio analyzer is an R&S UPV audio analyzer, and the bit error rate tester is a Keysight N4906B. If the modified audio analyzer's signal strength is less than 12 or the bit error rate tester's bit error rate is greater than 10%, then the modification is successful. -6 If so, it is considered abnormal; S4. Conduct the conduction safety margin test according to the conduction safety margin test method specified in the standard, and ensure that the audio analyzer or bit error rate tester is within the range specified in the appropriate test outline during the test: The specific method for conducting conduction safety margin tests is as follows: (1) The communication equipment is powered on and preheated to reach the required working state; (2) Secure the injection probe and monitoring probe to the cable bundle under test; (3) The receiving device scans within the applicable frequency range, and the communication device is in maximum transmission state to acquire the conducted environmental interference signal on the test cable; (4) Select the detected environment plus 6dB processing method, generate the target injection frequency curve, compare it with the CS114 limit and inject the larger value; (5) Perform injection scanning test on the injected frequency point. With the communication equipment in receiving mode, perform frequency scanning according to the standard. (6) Monitor whether the performance of the tested device is reduced by using an audio analyzer or a bit error rate tester. If a sensitive phenomenon occurs, record the sensitive phenomenon and the level of the interference signal. The test method described herein can be repeated in steps one through four within different operating frequency bands of the device under test until the test requirements are met.

[0020] The parts of this invention not described in detail are prior art.

[0021] The embodiments selected herein for the purpose of disclosing the inventive objectives are currently considered suitable; however, it should be understood that the invention is intended to include all variations and modifications of the embodiments that fall within the scope of this concept and invention.

Claims

1. A method for testing and evaluating the conduction safety margin of a communication device containing an antenna adjustment structure; characterized in that: Specifically, the following steps are included: S1. Communication equipment can autonomously select its operating frequency: The test communication device and the companion communication device were powered on and placed in an open test area with low and stable background noise. The surrounding electromagnetic environment was detected and analyzed by the receiver to prevent interference signals from affecting the normal operation of the equipment. The far-field conditions were calculated according to the antenna type and operating frequency of the equipment to ensure that the test communication device and the companion communication device were in the far-field communication simulation of the actual communication conditions. Then the test communication device and the companion communication device were powered on and operated normally. Both were set to the autonomous frequency selection mode. The two devices selected the operating frequency suitable for the current external electromagnetic environment conditions through autonomous frequency selection and recorded the current operating frequency. S2. Signal simulation method based on a signal source loaded with a radiating antenna: Select a suitable signal source as the simulation device according to the operating frequency, and use an antenna of the same model as the test communication device as the radiating antenna. Under the condition of ensuring the far field, disconnect the test communication device and the test communication device, and simulate the communication signal of the test communication device by loading the radiating antenna with the signal source, and establish a normal connection and working state between the simulated signal and the test communication device. S3. Load an audio analyzer or bit error rate tester onto the device under test; S4. Conduct the conduction safety margin test according to the conduction safety margin test method specified in the standard, and ensure that the audio analyzer or bit error rate tester is within the range specified in the appropriate test outline during the test.

2. The method for conducting safety margin test evaluation of communication equipment with antenna adjustment structure according to claim 1, characterized in that: The specific method for loading an audio analyzer or bit error rate tester onto the tested device as described in step S3 is as follows: Depending on the receiving port type of the communication device under test, load an audio analyzer or bit error rate tester onto the audio or digital port. During the loading process, try not to change the structure and internal circuitry of the device under test. If it is necessary to change the structure or internal circuitry of the device under test, the impact of the operation on the conducted safety margin test results of the device must be accurately assessed. If there is no impact or the impact is small, this method can be used. If there is a need for different frequencies, return to step S1.

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