A dual-frequency three-pulse radar wave control method and storage medium

Abstract

The present invention relates to G01S, and more specifically, to a dual-frequency three-pulse radar wave control method and storage medium. It includes: dual-frequency transmission, pulse transmission, and ABSW signal transmission. The present invention separates the radar short-range blind spot waveform and the long-range working waveform working frequency by dual-frequency switching, and combines the phased array phase-frequency scanning antenna to adjust the pitch pointing of the short-range beam and the pitch pointing of the long-range beam respectively, so as to achieve the effect of taking into account the detection of long-range targets and short-range targets, and improving the radar antenna gain and ensuring the radar detection power, and can effectively avoid the reduction of the pitch dimension and radar effective area caused by the large upward viewing angle.

Description

Technical Field

[0001] The present invention relates to G01S, and more specifically, to a dual-frequency three-pulse radar wave control method and a storage medium. Background Art

[0002] Phased array radar has the advantages of accurate phase shifting, stable performance, large frequency band and power capacity, easy and fast control, small excitation power and insertion loss, small size and light weight. One-dimensional active phased array radar is currently a more common two-coordinate (or three-coordinate) radar. The scanning working principle is as follows: Figure 1 As shown, beam scanning is performed by controlling the beam pointing angle θ.

[0003] In one-dimensional active phased array radars, existing beam control technologies mostly complete amplitude and phase control of single or multiple combined pulse excitation signals at a single fixed operating frequency. Taking one-dimensional azimuth scanning active phased array radar as an example, according to radar principles, the radar beam can realize beam scanning in the azimuth dimension, but has a fixed beam pointing in the elevation dimension, and the beam coverage is limited, making it difficult to effectively determine the orbit. For example, CN102540180A discloses a space-based phased array radar space multi-target orbit determination method to improve the effective estimation of weak space targets and the accuracy of target orbit determination.

[0004] However, when the radar is set up on the top of a mountain or on the top of a sentry tower, if you want to detect a target at a long distance, you need to adjust the antenna attitude to raise the pitch beam. If you want to detect a target at a close distance, you need to adjust the antenna attitude to lower the pitch beam. If you want to detect both long-distance and close-range targets at the same time, a large pitch angle is often required to ensure that the radar beam covers both close-range and long-range targets in the pitch dimension. However, a large pitch angle means that when designing the radar antenna, the size of the pitch dimension must be reduced, which reduces the effective area of ​​the radar and loses antenna gain, resulting in a loss of key performance such as radar detection power. Summary of the invention

[0005] In order to solve the above problems, a method is proposed that can simultaneously detect long-distance targets and short-distance targets, improve radar antenna gain, and ensure radar detection power, namely, dual-frequency three-pulse radar wave control technology. The first aspect of the present invention provides a dual-frequency three-pulse radar wave control method, including: dual-frequency transmission, pulse transmission, and ABSW signal transmission.

[0006] The dual-frequency transmission includes: after each CPI signal, transmitting the A-frequency wave control code, loading the A-frequency wave control code after the PRI signal rises, transmitting the B-frequency wave control code after the A-frequency is loaded, and loading the B-frequency wave control code after the ABSW signal rises;

[0007] The pulse transmission includes: after each PRI signal, three groups of radio frequency excitation pulses are sent in time division, and the radio frequency excitation pulses include a first pulse, a second pulse and a third pulse in sequence; the first pulse starts at time T4 after the rising edge of the PRI signal;

[0008] The ABSW signal transmission includes: the ABSW signal turns to a low level after each PRI signal, and the ABSW signal turns to a high level at time T4 before the rising edge of the third pulse.

[0009] The present invention limits the start time of dual-frequency transmission and pulse sending according to the CPI signal and the ABSW signal, so that the receiving and transmitting signals of the first two first pulses and the second pulse both work at the A frequency, and the signal waveform of the third pulse works at the B frequency, thereby adjusting the selection of short-range and long-range beams by selecting the A and B frequencies.

[0010] As a preferred technical solution of the present invention, the transmission time of the wave control code of frequency A is T 13 , loading time T 14 Satisfaction: T 13 ≥T3, T 14 ≥T4, T3 is the delay between the CPI signal and the first PRI signal.

[0011] As a preferred technical solution of the present invention, the dual-frequency transmission is repeated according to the PRI signal and the ABSW signal of the current CPI cycle, and the alternating operation of the A frequency and the B frequency is completed once in each PRI cycle until the current CPI cycle ends. Each CPI cycle includes M PRI signals, the CPI signal cycle is T1, the PRI signal cycle is T2, and the delay between the CPI signal and the first PRI signal is T3, which satisfies: T1 = M × T2 + T3.

[0012] As a preferred technical solution of the present invention, the pulse transmission includes: the first pulse is a signal waveform of a blind pulse of the second pulse, starting after T4 of the rising edge of the PRI signal, the emission of the first pulse takes T5, and the reception takes T6; the second pulse is a signal waveform of a blind pulse of the third pulse, the emission of the second pulse takes T7, and the reception takes T8; the third pulse is a working signal waveform, the emission of the third pulse takes T9, and the reception takes T 10 The transmission time is high level, the reception time is low level, the starting end of the high level is the rising edge, preferably, T6 ≥ T7, T8 ≥ T9.

[0013] As a preferred technical solution of the present invention, each RF excitation pulse corresponds to a TENA signal, a RENA signal, and a TRSW signal, and a T is left between the leading and trailing edges of the TENA signal and the PULSE signal. 11There is a protection time of T between the leading and trailing edges of the TRSW signal and the TENA signal. 11 During the protection time, the RENA signal and the TRSW signal are completely out of phase.

[0014] As a preferred technical solution of the present invention, the total time taken to send and receive the first pulse and the second pulse is T 15 The third working signal waveform works at the B frequency point, and the total time for sending and receiving is T 12 , the T 15 、T 12 satisfy:

[0015] T 15 =T5+T6+T7+T8, T 12 =T9+T 10 .

[0016] As a preferred technical solution of the present invention, the phase code of the A frequency and the phase code of the B frequency meet the following conditions in the transmitting or receiving state:

[0017] in It is the minimum quantization unit of the phase shifter;

[0018] Φ An is the phase value of the A frequency of each n-th radiating array element;

[0019] Φ Bn is the phase value of the B frequency of the nth radiating array element.

[0020] As a preferred technical solution of the present invention, the amplitude code of the A frequency and the amplitude code of the B frequency meet the following conditions in the transmitting or receiving state:

[0021]

[0022]

[0023] AMP An is the amplitude code of the nth radiating array element at the A-band operating frequency;

[0024] AMP Bn is the amplitude code of the nth radiating array element at the B-band operating frequency;

[0025] Tyler(n) is the nth weighting coefficient using the Taylor window function;

[0026] Λ fA is the initial amplitude error of the nth radiating array element at the A-band operating frequency;

[0027] Λ fB is the initial amplitude error of the nth radiating array element at the A-band operating frequency.

[0028] As a preferred technical solution of the present invention, the phase of each antenna array element at frequency A and the phase of frequency B satisfy:

[0029]

[0030]

[0031] where Φ An is the phase value of the A frequency of each n-th radiating array element;

[0032] Φ Bn is the phase value of the B frequency of the nth radiating array element;

[0033] C is the speed of light in air;

[0034] n is the number of the radiation array element;

[0035] d is the spacing between antenna radiating elements;

[0036] θ is the angle between the beam pointing and the antenna normal;

[0037] is the initial phase value of the nth channel at frequency A;

[0038] is the initial phase value of the nth channel at frequency B.

[0039] The PULSE pulse signal, CPI signal, PRI signal, ABSW signal, TENA signal, RENA signal, TRSW signal and other timing signals described in the present invention are all generated by a timing signal generation module, and the timing signal is generated at the same time as the pulse signal is generated.

[0040] A second aspect of the present invention provides a storage medium, characterized in that the storage medium is used to store a computer program, and the computer program is used to execute the dual-frequency three-pulse radar wave control method.

[0041] Compared with the prior art, the present invention has the following beneficial effects: the present invention separates the radar short-range blind spot waveform and the long-range working waveform working frequencies by dual-frequency switching, and combines with the phased array phase-frequency scanning antenna to adjust the pitch pointing of the short-range beam and the pitch pointing of the long-range beam respectively, so as to achieve the effect of taking into account the detection of long-range targets and short-range targets, improving the radar antenna gain and ensuring the radar detection power, and effectively avoiding the reduction of the pitch dimension and the radar effective area caused by the large upward viewing angle. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 Schematic diagram of one-dimensional active phase scanning operation.

[0043] Figure 2 The current fixed pitch pointing working effect diagram.

[0044] Figure 3 Working timing diagram.

[0045] Figure 4 Working effect diagram of dual-frequency three-pulse radar. DETAILED DESCRIPTION

[0046] Example

[0047] This example provides a dual-frequency three-pulse radar wave control method, including:

[0048] 1) The timing signal generation module generates PULSE pulse signals, and also generates CPI signals, PRI signals, ABSW signals, TENA signals, RENA signals, TRSW signals and other timing signals. The relationship between the timing signals is as follows: Figure 3 As shown;

[0049] 2) In the current CPI cycle, the operating frequency (including A frequency / B frequency) and beam direction of the next CPI cycle are transmitted. Each CPI cycle contains M PRI signals. The CPI signal cycle is T1, the PRI signal cycle is T2, and the delay between the CPI signal and the first PRI signal is T3. There is the following relationship:

[0050] T1=M×T2+T3

[0051] 3) After receiving the working frequencies (A frequency / B frequency) fA and fB and the azimuth beam pointing θ, the beam controller calculates the phase of each antenna array element at the A frequency and B frequency working frequencies in combination with the antenna radiation array element spacing d. The calculation formula is as follows:

[0052]

[0053]

[0054] Where:

[0055] Φ An is the phase value of the A frequency of each n-th radiating array element;

[0056] Φ Bn is the phase value of the B frequency of the nth radiating array element;

[0057] C is the speed of light in air;

[0058] n is the number of the radiation array element;

[0059] d is the spacing between antenna radiating elements;

[0060] θ is the angle between the beam pointing and the antenna normal;

[0061] is the initial phase value of the nth channel at frequency A;

[0062] is the initial phase value of the nth channel at frequency B;

[0063] 4) According to the above calculated phase values ​​of frequency A and frequency B and the minimum quantization unit of the phase shifter Calculate the phase codes at the two working frequencies of A and B in the transmitting and receiving states respectively. The calculation formula is as follows;

[0064]

[0065] 5) According to the amplitude error of each channel at the A-band and B-band operating frequencies and the minimum quantization unit of the attenuator Calculate the amplitude code at the two working frequencies of A and B in the transmitting and receiving states respectively. The calculation formula is as follows;

[0066]

[0067]

[0068] Where:

[0069] AMP An is the amplitude code of the nth radiating array element at the A-band operating frequency

[0070] AMP Bn is the amplitude code of the nth radiating array element at the B-band operating frequency

[0071] Tyler(n) is the nth weighting coefficient using the Taylor window function

[0072] Λ fA is the initial amplitude error of the nth radiating element at the A-band operating frequency

[0073] Λ fB is the initial amplitude error of the nth radiating element at the A-band operating frequency

[0074] 6) After each PRI signal, three groups of RF excitation pulses are sent in time. The first pulse starts after T4 of the rising edge of the PRI signal, and is the signal waveform of the blind pulse of the second pulse. Its transmission takes T5 and reception takes T6; the second pulse is the signal waveform of the blind pulse of the third pulse, and the transmission takes T7 and reception takes T8; the third pulse is the working signal waveform, and the transmission takes T9 and reception takes T10; the relationship between the durations is as follows:

[0075] T6≥T7, T8≥T9

[0076] 7) Each group of RF excitation signals has a corresponding TENA signal, RENA signal and TRSW signal. There is a T11 protection time between the leading and trailing edges of the TENA signal and the PULSE signal, and there is a T11 protection time between the leading and trailing edges of the TRSW signal and the TENA signal. The RENA signal and the TRSW signal are completely inverted. The timing relationship between the three is shown in Figure 2 .

[0077] 8) After each PRI signal, the ABSW signal turns to a low level; the ABSW signal turns to a high level T4 before the rising edge of the third pulse; the signal waveforms of the first two blind pulses work at the A frequency point, and the total time for sending and receiving is T15; the third working signal waveform works at the B frequency point, and the total time for sending and receiving is T12; the requirements are as follows.

[0078] T 15 =T5+T6+T7+T8, T 12 =T9+T 10

[0079] 9) After the CPI signal, the A-frequency wave control code is transmitted first, but there is no loading operation. The wave control code transmission takes time T13. After the rising edge of the PRI signal, the A-frequency wave control code is loaded. The loading takes time T14. The requirements are as follows;

[0080] T 13 ≥T3, T 14 ≥T4

[0081] 10) After completing the above loading operation, transmit the B-frequency wave control code and load it after the rising edge of the ABSW signal; after completing the loading operation, transmit the A-frequency wave control code and load it after the rising edge of the PRI signal;

[0082] 11) Thereafter, in the current CPI cycle, the above steps will be followed according to the periodic PRI signal and ABSW signal, and the alternating operation of frequency A and frequency B will be completed once in each PRI cycle until the current CPI cycle ends.

[0083] By using the method provided by the present invention, the receiving and transmitting signals of the first two blind pulses are both operated at the A frequency, and the signal waveform of the third pulse is operated at the B frequency. When the radar selects the crack waveguide antenna array or the phase-frequency scanning antenna array in the form of a slow wave line, the pitch pointing of the short-range beam and the pitch pointing of the long-range beam can be adjusted respectively by reasonably selecting the working frequency points of the A frequency and the B frequency. The final beam coverage effect is as follows: Figure 4 As shown, both near and far targets can be covered.

[0084] Taking the working scene of a battlefield reconnaissance radar as an example, when the radar is installed at a height of 200 meters, the minimum effective distance is 50m, the maximum effective distance is 5km, and full-range detection without blind spots is required, when using traditional wave control technology, a single elevation beam needs to cover 8°, and the antenna beam antenna gain is only 30.5dB; when using the dual-frequency multi-pulse provided by the present invention, the width of a single elevation beam is 4°, the frequency sweep coverage range is 4°, and the antenna gain is 32dB. Compared with traditional wave control technology, when other radar indicators remain unchanged, the detection power of the radar is increased by about 18.85%.

Claims

1. A dual-frequency three-pulse radar wave control method, characterized in that: include: Dual-frequency transmission, pulse transmission, ABSW signal transmission; The dual-frequency transmission includes: after each CPI signal, transmitting the A-frequency wave control code, loading the A-frequency wave control code after the PRI signal rises, transmitting the B-frequency wave control code after the A-frequency is loaded, and loading the B-frequency wave control code after the ABSW signal rises; The pulse transmission includes: after each PRI signal, three groups of radio frequency excitation pulses are sent in time division, and the radio frequency excitation pulses include a first pulse, a second pulse and a third pulse in sequence; the first pulse starts at time T4 after the rising edge of the PRI signal; The ABSW signal transmission includes: the ABSW signal turns to a low level after each PRI signal, and the ABSW signal turns to a high level at time T4 before the rising edge of the third pulse; The pulse transmission includes: the first pulse is a signal waveform of a blind pulse of the second pulse, starting after T4 of the rising edge of the PRI signal, the emission of the first pulse takes T5, and the reception takes T6; the second pulse is a signal waveform of a blind pulse of the third pulse, the emission of the second pulse takes T7, and the reception takes T8; the third pulse is a working signal waveform, the emission of the third pulse takes T9, and the reception takes T 10 ; The transmission is high level, the reception is low level, and the starting end of the high level is the rising edge. .

2. The dual-frequency three-pulse radar wave control method according to claim 1, characterized in that: The transmission time of the A-frequency wave control code is T 13 , loading time T 14 satisfy: , T3 is the delay between the CPI signal and the first PRI signal.

3. The dual-frequency three-pulse radar wave control method according to claim 1, characterized in that: Each RF excitation pulse corresponds to the TENA signal, RENA signal, and TRSW signal; there is a T between the leading and trailing edges of the TENA signal and the PULSE signal. 11 There is a protection time of T between the leading and trailing edges of the TRSW signal and the TENA signal. 11 During the protection time, the RENA signal and the TRSW signal are completely out of phase.

4. The dual-frequency three-pulse radar wave control method according to claim 1, characterized in that: The total time taken to send and receive the first pulse and the second pulse is T 15 The third working signal waveform works at the B frequency point, and the total time for sending and receiving is T 12 , the T 15 , T 12 satisfy: 。 5. The dual-frequency three-pulse radar wave control method according to claim 1, characterized in that: The phase code of the A frequency , B frequency phase code In the transmitting or receiving state, the following conditions are met: ; in It is the minimum quantization unit of the phase shifter; is the phase value of the A frequency of the nth radiating array element; is the phase value of the B frequency of the nth radiating array element.

6. The dual-frequency three-pulse radar wave control method according to claim 1, characterized in that: The amplitude code of the A frequency and the amplitude code of the B frequency satisfy the following conditions in the transmitting or receiving state: in is the amplitude code of the nth radiating array element at the A-band operating frequency; is the amplitude code of the nth radiating array element at the B-band operating frequency; is the nth weighting coefficient using Taylor window function; is the initial amplitude error of the nth radiating array element at the A-band operating frequency; is the initial amplitude error of the nth radiating array element at the B-band operating frequency.

7. The dual-frequency three-pulse radar wave control method according to claim 5, characterized in that: The phase value of each antenna array element at frequency A and frequency B satisfies: ； ； in is the phase value of the A frequency of the nth radiating array element; is the phase value of the B frequency of the nth radiating array element; C is the speed of light in air; n is the number of the radiation array element; d is the spacing between antenna radiating elements; is the angle between the beam pointing and the antenna normal; is the initial phase value of the nth channel at frequency A; is the initial phase value of the nth channel at frequency B.

8. The dual-frequency three-pulse radar wave control method according to any one of claims 1 to 7, characterized in that: Repeat dual-frequency transmission according to the PRI signal and ABSW signal of the current CPI cycle, and complete the alternation of A frequency and B frequency once in each PRI cycle until the end of the current CPI cycle; Each CPI cycle includes M PRI signals. The CPI signal cycle is T1, the PRI signal cycle is T2, and the delay between the CPI signal and the first PRI signal is T3, satisfying: .

9. A storage medium, characterized in that: The storage medium is used to store a computer program, and the computer program is used to execute the dual-frequency three-pulse radar wave control method according to any one of claims 1 to 8.

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