A method for self-checking of a radar seeker receiving channel radio frequency cable

Abstract

The application relates to a radar seeker receiving channel radio frequency cable self-checking method, which is used for solving the problem of radar seeker radio frequency cable self-checking. According to the characteristics of the abnormal state of the radar seeker receiving channel radio frequency cable, the radar seeker test signal is utilized to control the radar seeker position marker to perform two-dimensional scanning and simultaneously calculate the phase values between channels. Whether the state of the radar seeker radio frequency cable is abnormal is judged by comparing the change range of the phase values between channels. The experimental results show that the method can complete the self-checking of the radar seeker receiving channel radio frequency cable.

Description

Technical Field

[0001] This invention relates to the field of radar data processing, and more specifically to a method for implementing the self-test function of the radio frequency cable of a radar seeker. Background Technology

[0002] The receiving channel RF cable connects to the frequency synthesizer and transceiver module at both ends, and is responsible for signal transmission between them, such as... Figure 1 The blue cable is shown. Because the transceiver module is mounted on the coordinate sensor, which mechanically scans for azimuth and elevation dimensions according to commands, the RF cable will repeatedly bend and stretch as the sensor scans. Over time, this can easily damage the RF cable. Figure 2 As shown. After the RF cable is installed in the radar seeker, it undergoes systematic testing and performance calibration along with the seeker. It's usually difficult for the entire system to perform a dedicated self-test on the signal cable. In actual use of the radar seeker, a common abnormality in the receiver channel RF cable is a broken cable sheath leading to poor contact of the internal metal wires. Because angle measurement receivers are highly sensitive to phase changes between channels, even minor damage can cause a sudden phase shift of tens of degrees between the sum and difference channels, easily leading to angle measurement anomalies, the seeker's inability to track the target, and guidance failure. Each component within the seeker can use a specially designed internal self-test circuit to ensure that any faults are reported during self-testing, thus reducing or avoiding further impact on the entire system. However, despite the critical importance of the RF cable for ensuring the performance of the seeker system, it is difficult to inspect. During the development of a certain seeker, damaged cables were difficult to distinguish from normal cables, and to date, there are no reports of using self-testing to determine whether the receiver channel cable is damaged.

[0003] The radar seeker test signal is generated by the radar seeker frequency synthesizer. It is fed into the single-pulse sum and difference network through the antenna test channel via a directional coupler. After the test signal is processed by the antenna single-pulse sum and difference network, it is synthesized into sum, azimuth difference and elevation difference signals and sent to the three corresponding receiving channels. These three signals enter the frequency synthesizer from the transceiver module through three RF cables, and then the signal processor performs subsequent processing. Summary of the Invention

[0004] Technical problems to be solved

[0005] To avoid the shortcomings of existing technologies and considering the characteristics of abnormal states in radio frequency cables, this invention provides a self-testing method for radio frequency cables in the receiving channel of a radar seeker, utilizing radar seeker test signals.

[0006] Technical solution

[0007] A self-testing method for the radio frequency cable of a radar seeker receiving channel is characterized by: using the radar seeker test signal to control the radar seeker positioner to perform a two-dimensional scan and simultaneously calculate the phase value between channels; and judging whether the state of the radar seeker radio frequency cable is abnormal by comparing the range of change of the phase value between channels.

[0008] The steps are as follows:

[0009] Step 1: Apply external voltage to the radar seeker. After the radar seeker data processor is working normally, it controls the radar seeker to start generating test signals.

[0010] Step 2: After the radar seeker data processor is working normally, the position pointer is powered on and simultaneously sends a zero-position command, which is held for 1 second; using the sum path as a reference, calculate the phase values ​​of the azimuth difference path and the elevation difference path relative to the sum path respectively.

[0011] Step 3: Set the beacon to scan the azimuth and elevation dimensions simultaneously, and the scanning angle range should cover the range of indicators used by the radar seeker; using the sum path as the reference, calculate the phase values ​​of the azimuth difference path and the elevation difference path relative to the sum path respectively.

[0012] Step 4: Statistically analyze the phase values ​​of the azimuth difference path and the pitch difference path respectively, and compare them with the normal test results: If the azimuth difference phase value fluctuates abnormally while the pitch phase value fluctuates normally, the azimuth difference path cable is considered abnormal; if the pitch difference phase value fluctuates abnormally while the azimuth phase value fluctuates normally, the pitch difference path cable is considered abnormal; if both the azimuth difference and pitch difference phase values ​​fluctuate abnormally, the entire path cable is considered abnormal or all three paths are abnormal.

[0013] In step 4, the criterion for determining abnormal fluctuations is that the phase fluctuation value is greater than 10 degrees.

[0014] In step 4, the criterion for determining normal fluctuations is that the phase fluctuation value is less than 10 degrees.

[0015] Beneficial effects

[0016] This invention provides a self-testing method for the RF cable of a radar seeker receiving channel, addressing the problem of self-testing for radar seeker RF cables. Targeting the characteristics of abnormal states in the RF cable of a radar seeker receiving channel, the method utilizes radar seeker test signals to control the radar seeker's position pointer to perform a two-dimensional scan while simultaneously calculating the phase values ​​between channels. By comparing the range of changes in the phase values ​​between channels, the method determines whether the radar seeker RF cable is in an abnormal state. Experimental results show that the method of this invention can successfully perform self-testing of the RF cable of a radar seeker receiving channel. Attached Figure Description

[0017] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0018] Figure 1 Radar seeker RF cable connection diagram;

[0019] Figure 2 Cable core broken;

[0020] Figure 3 After implementing this invention, the self-test result of the radio frequency cable of the receiving channel of a radar seeker was normal.

[0021] Figure 4 An abnormal self-test result was obtained from the radio frequency cable of the receiving channel of a radar seeker after implementing this invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0023] A radar seeker contains three radio frequency (RF) signals, defined as the sum, azimuth difference, and elevation difference channels. The radar seeker's position pointer performs a mechanical scan, simultaneously calculating the phase values ​​between the three RF signals (the phase value calculation method is described in Chapter 7, Angle Measurement, of "Radar Principles"). Testing on multiple radar seeker prototypes revealed that when the cable was intact, even with continuous scanning by the position pointer, the phase fluctuation between the sum and difference receiving channels was less than 10 degrees. However, when the receiving channel RF cable was damaged, the phase value change reached tens of degrees. By comparing the phase value changes, the condition of the RF cable can be determined. Details are as follows:

[0024] After the radar seeker is externally powered on and the signal processor self-tests normally, the seeker is set to operate under fixed frequency and fixed power conditions. The radar seeker is controlled to continuously generate test signals, while the radar seeker's position pointer is kept at zero for 1 second. Using the sum path as a reference, the phase values ​​of the azimuth difference path and elevation difference path relative to the sum path are calculated. Then, the radar seeker's position pointer is controlled to simultaneously begin mechanical scanning in both azimuth and elevation dimensions. The scanning angle range should cover the range of specifications used by the radar seeker, aiming to ensure that the bending degree of the RF cable covers the operating conditions. Simultaneously, the phase values ​​of the azimuth difference path and elevation difference path relative to the sum path are calculated. After the radar seeker's position pointer scan is completed, the phase value variation range of the azimuth difference path and elevation difference path is statistically analyzed and compared with the normal variation values ​​(generated during the initial calibration of the radar seeker prototype). For a certain radar seeker prototype, under normal RF cable conditions, the phase value fluctuation of the azimuth difference path and elevation difference path relative to the sum path is within 10 degrees; a fluctuation greater than 10 degrees is considered abnormal. When the azimuth difference phase value fluctuates abnormally while the pitch phase value fluctuates normally, the azimuth difference cable is considered abnormal. When the pitch difference phase value fluctuates abnormally while the azimuth phase value fluctuates normally, the pitch difference cable is considered abnormal. When both the azimuth and pitch difference phase values ​​fluctuate abnormally, the all-path cable is considered abnormal, or all three paths are considered abnormal.

[0025] To enable those skilled in the art to better understand the present invention, the present invention will be described in detail below with reference to specific embodiments.

[0026] Example:

[0027] 1. When an external voltage is applied to the radar seeker, the radar seeker data processor operates normally. The data processor sets the seeker to operate under fixed frequency and fixed power conditions, and controls the radar seeker to start generating test signals.

[0028] 2. The control coordinate sensor is in the zero position, meaning the data processor sends a set command to the coordinate sensor, with a control quantity of 0. This state is maintained for 1 second. Using the sum path as a reference, calculate the phase values ​​of the azimuth difference path and elevation difference path relative to the sum path, respectively.

[0029] 3. Set the beacon to scan simultaneously in both azimuth and elevation dimensions, ensuring the scanning angle range covers the range of parameters used by the radar seeker. Using the sum path as a reference, calculate the phase values ​​of the azimuth difference path and elevation difference path relative to the sum path, respectively.

[0030] 4. Statistically analyze the phase values ​​of the azimuth difference and elevation difference paths separately. Compare these values ​​with normal test results. If the azimuth difference phase value fluctuates abnormally (i.e., phase fluctuation greater than 10 degrees) while the elevation phase value fluctuates normally (i.e., phase fluctuation less than 10 degrees), the azimuth difference path cable is considered abnormal. If the elevation difference phase value fluctuates abnormally (i.e., phase fluctuation greater than 10 degrees) while the azimuth phase value fluctuates normally (i.e., phase fluctuation less than 10 degrees), the elevation difference path cable is considered abnormal. If both the azimuth and elevation difference phase values ​​fluctuate abnormally (i.e., phase fluctuation greater than 10 degrees), the entire path cable is considered abnormal, or all three paths are considered abnormal.

[0031] Multiple self-tests of the radar seeker's radio frequency cable were conducted using this invention, and the radio frequency cable self-test results were as follows: Figure 3 As shown, both azimuth and elevation phase fluctuations are less than 10 degrees, indicating a normal RF cable self-test result. The result for an RF cable malfunction is as follows: Figure 4 As shown, the azimuth phase value fluctuates by approximately 100 degrees, while the elevation phase value fluctuates by less than 10 degrees. At this point, the RF cable self-test result indicates an azimuth difference and cable abnormality. Experimental results demonstrate that the method of this invention can complete the self-test of the RF cable status of the radar seeker's receiving channel.

[0032] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the scope of the technology disclosed in the present invention, and such modifications or substitutions should all be covered within the scope of protection of the present invention.

Claims

1. A self-test method for the radio frequency cable of a radar seeker receiving channel, characterized in that: Using the radar seeker test signal, the radar seeker's position pointer is controlled to perform a two-dimensional scan while simultaneously calculating the phase values ​​between channels. By comparing the range of changes in the phase values ​​between channels, it is determined whether the radar seeker's RF cable is in abnormal condition. The steps are as follows: Step 1: Apply external voltage to the radar seeker. After the radar seeker data processor is working normally, it controls the radar seeker to start generating test signals. Step 2: After the radar seeker data processor is working normally, the position pointer is powered on and simultaneously sends a zero-position command, which is held for 1 second; using the sum path as a reference, calculate the phase values ​​of the azimuth difference path and the elevation difference path relative to the sum path respectively. Step 3: Set the beacon to scan the azimuth and elevation dimensions simultaneously, and the scanning angle range should cover the range of indicators used by the radar seeker; using the sum path as the reference, calculate the phase values ​​of the azimuth difference path and the elevation difference path relative to the sum path respectively. Step 4: Statistically analyze the phase values ​​of the azimuth difference path and the pitch difference path respectively, and compare them with the normal test results: if the azimuth difference phase value fluctuates abnormally and the pitch phase value fluctuates normally, the azimuth difference path cable is considered abnormal. When the pitch difference phase value fluctuates abnormally while the azimuth phase value fluctuates normally, the pitch difference cable is considered abnormal. When the azimuth difference and pitch difference phase values ​​fluctuate abnormally, the cable is considered abnormal or all three are abnormal; the criterion for judging abnormal fluctuation is that the phase fluctuation value is greater than 10 degrees. The criterion for normal fluctuation is that the phase fluctuation value is less than 10 degrees.

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