Test system of direct injection test method taking ELT as object

Abstract

The utility model relates to the technical field of emergency positioning transmitter testing, in particular to a testing system of a direct injection testing method taking an ELT as an object, which comprises a signal source used as a signal generating device of the testing system; the power amplifier is used as a power amplification device in the test system and is used for amplifying weak signals output by a signal source, the power amplifier is connected with the signal source, and the frequency of the power amplifier is consistent with the frequency required by the signal source; the directional coupler is used for monitoring power, stabilizing the amplitude of source output power and isolating a signal source, and the directional coupler is connected with the power amplifier; the ELT is connected with the directional coupler, and the directional coupler is used for injecting a signal into a radio frequency port of the ELT; through cooperative work of the components, direct injection testing of the ELT is achieved, and the problems that in the prior art, a direct injection testing method is brief in specification and lacks specific configuration and index requirements are solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of emergency locator transmitter test, especially with the test system of direct injection test method for the object of ELT. BACKGROUND

[0002] RTCA / D0-204A-2007 "Minimum Operational Performance Standards (MOPS) for 406MHz Emergency Locator Transmitters (ELT)" specifies the direct injection test method and high field strength radiation exposure method of ELT (emergency locator transmitter), however, the provision of direct injection test method is relatively brief, lacks specific test configuration and equipment technical index requirement, and cannot effectively guide the equipment selection and building of test system.

[0003] As a replacement method, although high field strength radiation exposure method can achieve the purpose of examining the anti-interference ability of ELT, its test principle is completely different from that of direct injection method, and the method needs to be carried out in a shielded anechoic chamber or reverberation chamber, so that the test system is complex, is restricted by site and equipment capacity, and leads to high test cost.

[0004] The prior art has the following defects: first, the provision of direct injection test method in RTCA / D0-204A-2007 is too brief, and lacks specific test configuration and equipment technical index requirement; second, high field strength radiation exposure method needs special test environment, such as a shielded anechoic chamber or a reverberation chamber, which greatly increases the test cost and complexity; finally, the prior art lacks a simple, efficient and low-cost ELT direct injection test system.

[0005] In order to solve these problems, it is urgent to develop an ELT direct injection test system to fill the blank of ELT direct injection test capability specified in RTCA / D0-204A-2007. Such a system should not be limited by site conditions, be simple to build, be easy to implement, and be able to examine the anti-interference ability of ELT in a short time and at a low cost. UTILITY MODEL CONTENT

[0006] The utility model aims at solving the defects in the prior art and provides a test system of direct injection test method for the object of ELT.

[0007] To achieve the above object, the utility model adopts the technical scheme as follows: a test system of direct injection test method for the object of ELT, comprising:

[0008] Signal source, used as signal generating device of test system;

[0009] Power amplifier, used as power amplifying device of test system, amplifying weak signal outputted by signal source, the power amplifier is connected with the signal source, and the frequency of the power amplifier should be consistent with the required frequency of the signal source;

[0010] Directional coupler, used for power monitoring, source output power stabilization and signal source isolation, and the directional coupler is connected with the power amplifier;

[0011] ELT, connected with the directional coupler, and the directional coupler injects signal into the radio frequency port of the ELT;

[0012] Power meter, used for monitoring the amplitude of the injected signal, and connected with the directional coupler;

[0013] Test computer, used for controlling the signal transmission and operation of the whole test system.

[0014] Preferably, the signal source can cover the frequency of 118MHz-112.25MHz, 121.75-136.975MH, 134.50MHz-136.750MHz and 405.528MHz-406.528Mhz.

[0015] Preferably, the signal source is provided with 1kHz square wave modulation, and the modulation depth reaches 90%.

[0016] Preferably, an attenuator is connected on the line between the power amplifier and the directional coupler, and the attenuator is used for signal attenuation, adjusting the amplitude and power of the signal, preventing signal overload and protecting the ELT.

[0017] Preferably, a fifty-ohm load is connected on the line between the directional coupler and the radio frequency port of the ELT, and the fifty-ohm load is used for providing ideal impedance load in the test system calibration process.

[0018] Preferably, the measurement accuracy of the power meter reaches ±2dB.

[0019] Compared with the prior art, the test system of the direct injection test method for the ELT provided by the application has the following beneficial effects: the test system of the direct injection test method for the ELT provided by the application includes a signal source, a power amplifier, a directional coupler, an ELT, a power meter and a test computer, and the direct injection test of the ELT is realized through the cooperative work of these components, the problems of simple and brief direct injection test method, lack of specific configuration and index requirement in the prior art are solved, and the test system has the advantages of simplicity, high efficiency, low cost and no site limitation. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 This is a flowchart illustrating the basic configuration of the direct injection test system for ELT of this utility model. Detailed Implementation

[0021] The following description is intended to disclose the present invention so that those skilled in the art can implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0022] Application Scenario: In existing technologies, RTCA / DO-204A-2007 specifies the direct injection test method, but its method is relatively simple and lacks detailed test configuration and equipment specifications, failing to guide the selection and setup of test system equipment for the direct injection method. Furthermore, existing technologies employ high-intensity radiation irradiation, requiring testing in a shielded anechoic chamber or reverberation chamber, resulting in complex test systems constrained by site and equipment capabilities, and high testing costs. Therefore, a direct injection test system for ELT that can overcome these limitations is needed.

[0023] like Figure 1 The test system shown is a direct injection test method targeting ELT, comprising:

[0024] A signal source is a device used to generate signals for a test system.

[0025] A power amplifier is used as a power amplification device in a test system to amplify the weak signal output from a signal source. The power amplifier is connected to the signal source, and the frequency of the power amplifier should be consistent with the required frequency of the signal source.

[0026] A directional coupler is used for power monitoring, source output power stabilization, and signal source isolation. The directional coupler is connected to the power amplifier.

[0027] ELT, connected to the directional coupler, which injects signals into the ELT RF port;

[0028] A power meter, used to monitor the amplitude of the injected signal, is connected to the directional coupler;

[0029] The test computer controls the signal transmission and operation of the entire test system. During operation, the signal source acts as the signal generator of the test system, producing the required test signal. The power amplifier amplifies the weak signal output by the signal source to ensure that the signal strength meets the test requirements. The directional coupler is used to monitor and stabilize the power, isolate the signal source, and inject the signal into the ELT RF port. The power meter is used to monitor the amplitude of the injected signal to ensure the accuracy of the signal. The test computer controls the signal transmission and operation of the signal source, power amplifier, and directional coupler to ensure the coordinated operation of the entire system.

[0030] Through the technical means, the test system can be built simply, easily implemented and low in cost without being restricted by site conditions, and is used for examining the anti-interference capability of the ELT, and fills the blank in the prior art.

[0031] In the prior art, the high field strength radiation irradiation method needs to be tested in a shielding darkroom or reverberation chamber, the test system is complex, is restricted by site and equipment capacity, and is high in test cost.

[0032] As an embodiment of the utility model, the frequency covered by the signal source is 118MHz~112.25MHz, 121.75~136.975MH, 134.50MHz~136.750MHz and 405.528MHz~406.528Mhz.

[0033] The frequency coverage range of the signal source is wide, and covers multiple frequency bands. These frequency bands include 118MHz to 112.25MHz, 121.75MHz to 136.975MHz, 134.50MHz to 136.750MHz and 405.528MHz to 406.528MHz. The signal source designed in this way can meet the test requirements of different frequency bands, and ensure that the test system can perform comprehensive frequency coverage testing on the ELT. In solving the problem of insufficient frequency coverage range of the signal source, the wide frequency coverage characteristic of the signal source plays a key role, and by providing test signals of multiple frequency bands, the applicability and effectiveness of the test system are ensured.

[0034] Specifically, the frequency coverage range of the signal source can be realized in multiple ways, for example, using a frequency synthesizer to generate the required frequency signal, or using multiple signal generators to cover different frequency bands. The frequency synthesizer can realize accurate frequency output by adjusting the internal reference signal and frequency multiplier, ensuring the accuracy and stability of frequency coverage. As a preferred embodiment, a multi-band filter can be integrated in the signal source to reduce interference during frequency switching and improve the purity and stability of the signal.

[0035] Therefore, the present application effectively solves the problem of insufficient frequency coverage range of the signal source in the prior art by designing a signal source with wide frequency coverage. Compared with the prior art, the signal source in the present application can cover more frequency bands, meet different test requirements, improve the applicability and effectiveness of the test system, reduce the test cost, and simplify the construction and operation of the test system.

[0036] As an embodiment of the utility model, the signal source has 1kHz square wave modulation, satisfying 90% modulation depth; when working, through the signal source having 1kHz square wave modulation and satisfying 90% modulation depth, it can ensure that the signal output by the signal source has sufficient modulation depth, and this modulation depth can effectively simulate the signal characteristics in the actual use environment in direct injection test, thereby accurately evaluating the anti-interference ability of ELT.

[0037] The 1kHz square wave modulation of the signal source is realized by generating a square wave signal with a frequency of 1kHz inside the signal source and modulating it with the main signal, and the modulation depth of 90% means that the amplitude variation range of the modulated signal accounts for 90% of the amplitude of the main signal. Specifically, the signal source can realize this modulation mode through internal circuit or connect an external modulator to the signal source. In addition, the control of modulation depth can be realized by adjusting the amplitude of the modulated signal to ensure that the modulation depth is stable at 90%.

[0038] The present application can effectively simulate the signal characteristics in the actual use environment by using a signal source with 1kHz square wave modulation and satisfying 90% modulation depth. Compared with the prior art, the technical scheme of the present application does not need complex test environment, reduces the test cost and improves the test efficiency. Therefore, the anti-interference ability of ELT can be accurately evaluated in a short time and at a low cost.

[0039] As an embodiment of the utility model, an attenuator is connected between the power amplifier and the directional coupler, which is used for signal attenuation, adjusting the amplitude and power of the signal, preventing signal overload and protecting ELT; when working, an attenuator is connected between the power amplifier and the directional coupler, and the function of the attenuator is to attenuate the signal, adjust the amplitude and power of the signal, which can prevent signal overload and protect ELT. The attenuator adjusts the intensity of the signal to ensure that the signal is within a safe range and avoid damaging the ELT. This technical feature can effectively control the signal intensity by adding an adjusting device in the signal transmission process, solving the potential risk problem of signal overload to ELT.

[0040] The attenuator can adopt various implementation manners, for example, a fixed attenuator can be used to provide constant signal attenuation, and a variable attenuator can be used to adjust the attenuation amount of the signal as required. The fixed attenuator is generally composed of a resistor, has simple structure and low cost, and is suitable for application scenarios with stable signal attenuation requirements. The variable attenuator can be adjusted through a mechanical or electronic manner, has higher flexibility, and is suitable for application scenarios with large signal intensity variation. As a preferred implementation manner, the electronic variable attenuator can realize accurate attenuation amount adjustment through a control voltage or a digital signal, and can better adapt to different test requirements.

[0041] As an implementation manner of the utility model, a fifty-ohm load is connected on the line between the directional coupler and the ELT radio frequency port, and the fifty-ohm load is used to provide an ideal impedance load during the test system verification process; during operation, by adding a fifty-ohm load between the directional coupler and the ELT radio frequency port, the system can be ensured to have a stable impedance environment during the verification process, thereby improving the accuracy and consistency of the test results; the fifty-ohm load is used to provide an ideal impedance load, and a standard fifty-ohm coaxial cable connection mode can be used to ensure impedance matching. At the same time, a high-precision fifty-ohm terminal load device can be used to further ensure the stability of the impedance. Another implementation manner is to use an adjustable impedance load, which can be fine-tuned according to different test requirements, thereby adapting to different test environments. In addition, a temperature compensation function can be added to the load device to ensure that the impedance characteristics remain stable under different temperature conditions.

[0042] The utility model solves the problem of providing an ideal impedance load during the test system verification process by connecting a fifty-ohm load between the directional coupler and the ELT radio frequency port. Compared with the prior art, the utility model can provide a stable impedance environment during the test system verification process, thereby improving the accuracy and consistency of the test results and avoiding test errors caused by impedance mismatch. Therefore, the utility model realizes a more reliable and accurate verification process in the test system, thereby improving the performance and reliability of the overall test system.

[0043] As an implementation manner of the utility model, the power meter measurement accuracy meets ±2dB; the measurement accuracy of the power meter plays a key role in the direct injection test method, and by ensuring that the measurement accuracy of the power meter reaches ±2dB, the accuracy and reliability of the test system can be improved. The utility model solves the problem of signal amplitude monitoring accuracy during the test process by setting the measurement accuracy index of the power meter, thereby ensuring the accuracy and consistency of the test results.

[0044] In practical applications, the measurement accuracy of the power meter can be achieved in various ways; for example, high-precision calibration equipment can be used to periodically calibrate the power meter to ensure that its measurement accuracy is within ±2dB; in addition, high-quality power meter sensors and optimized measurement circuit design can be selected to improve measurement accuracy; further, an automatic compensation mechanism can be introduced into the test system to adjust the measurement results in real time according to environmental changes to maintain measurement accuracy.

[0045] The present application sets the measurement accuracy index of the power meter, significantly improves the accuracy and reliability of the direct injection test system, and compared with the prior art, the technical scheme of the present application is not limited by site conditions, is simple to build, easy to implement, and can complete the examination of the ELT anti-interference ability in a short time and at a low cost. Therefore, the present application not only solves the problem of high test cost and complex system in the prior art, but also fills the gap of the direct injection test method in RTCA / DO-204A-2007.

[0046] I. Test system test parameter range and accuracy:

[0047] 1. Frequency range

[0048] 118MHz~112.25MHz;121.75~136.975MHz;134.50MHz~136.750MHz;405.528MHz~406.528Mhz.

[0049] 2. Signal strength: 24dBm~26dBm

[0050] 3. Measurement tolerance

[0051] Frequency: ±2%;

[0052] Amplitude: measurement receiver, ±2dB;

[0053] Amplitude: test system (including measurement receiver, coaxial cable, directional coupler, etc.), ±3dB.

[0054] II. Test method

[0055] When modulating 121.5MHz with a 1kHz square wave, the ELT unit operating in 121.5 mode shall not be activated or damaged, and +24dBm is directly coupled to the ELT antenna terminal at least 90% of the depth from 118MHz to 121.250MHz and from 121.75 to 136.975MHz; or connected to the ELT unit using an internal installation antenna.

[0056] When modulated with a 1 kHz square wave at 406 MHz, the ELT unit operating in the 406 MHz mode must not be activated or damaged from at least 90% depth of direct coupling to the ELT antenna terminal of +26 dBm from 134.5083 MHz to 136.750 MHz and 405.528 MHz to 406.528 MHz; or connected to an ELT unit using an internally mounted antenna.

[0057] The basic principle, main features and advantages of the present application are shown and described above. Those skilled in the art should understand that the present application is not limited by the above examples, and the above examples and descriptions in the specification are only the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application.

Claims

1. A test system for a direct injection test method targeting ELT, characterized in that, include: A signal source is a device used to generate signals for a test system. A power amplifier is used as a power amplification device in a test system to amplify the weak signal output from a signal source. The power amplifier is connected to the signal source, and the frequency of the power amplifier should be consistent with the required frequency of the signal source. A directional coupler is used for power monitoring, source output power stabilization, and signal source isolation. The directional coupler is connected to the power amplifier. ELT, connected to the directional coupler, which injects signals into the ELT RF port; A power meter, used to monitor the amplitude of the injected signal, is connected to the directional coupler; The test computer is used to control the signal transmission and operation of the entire test system.

2. The test system for a direct injection test method targeting ELT according to claim 1, characterized in that, The signal source can cover frequencies of 118MHz~112.25MHz, 121.75~136.975MHz, 134.50MHz~136.750MHz and 405.528MHz~406.528MHz.

3. The test system for a direct injection test method targeting ELT according to claim 1, characterized in that, The signal source has 1kHz square wave modulation, satisfying a modulation depth of 90%.

4. The test system for a direct injection test method targeting ELT according to claim 1, characterized in that, An attenuator is connected on the line between the power amplifier and the directional coupler. The attenuator is used to attenuate the signal and adjust the amplitude and power of the signal.

5. The test system for a direct injection test method targeting ELT according to claim 1, characterized in that, A 50-ohm load is connected on the line between the directional coupler and the ELT RF port. The 50-ohm load is used to provide an ideal impedance load during the test system verification process.

6. The test system for a direct injection test method targeting ELT according to claim 1, characterized in that, The power meter has a measurement accuracy of ±2dB.

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