Mixing frequency processing device and processing method for dual-band multi-base weather radar

Abstract

The present invention discloses a frequency mixing processing device and a processing method for a dual-band multi-base weather radar, which is characterized by comprising at least one local transmitting-end device that modulates a local-end radio frequency reference signal into an optical domain, and at least two remote receiving devices that match the local transmitting-end device and modulate the optical domain back into an optical signal after processing through an amplifier. The local end uses an electro-optical modulator to implement frequency mixing modulation on a pulse signal, restores the optical signal to an RF signal through a photoelectric detector, and amplifies and radiates the microwave signal through a local transmitting antenna with different wavelengths. The radar receiver is arranged at the remote end, and the signal returns to the ground through a receiving antenna, is modulated back into an optical signal after processing through an amplifier, and frequency mixing processing of the signal is implemented in the optical domain. Photonics is used to implement a dual-band, multi-base weather radar, and the device can simultaneously measure different meteorological parameters, and the device has a simple structure and stable performance.

Description

Technical Field

[0001] The invention relates to the technical field of a dual-band multi-base weather radar frequency mixing device. Background Art

[0002] With the increasing development of radar technology, radar technology has been widely used in the field of meteorology. Various forms of radar are used to detect and study the atmosphere. Meteorological radar has become an indispensable tool for weather forecasting and atmospheric science research.

[0003] The wavelength occupied by radar equipment is very wide, and meteorological radars of different bands have different characteristics. Decimeter wave radar (wavelength range of 1m-10cm) is mainly used for wind measurement; centimeter wave radar (wavelength range of 10cm-1cm) is mainly used for rain measurement; millimeter wave radar (wavelength range of 1cm-1mm) is mainly used to study the physical process of cloud and precipitation formation and development. Due to the influence of electronic devices and antenna size, it is difficult to achieve direct fusion of meteorological radars of different bands.

[0004] Single-base radars generally use the same transmission and reception site, that is, the receiving station and the transmitting station are located in the same area, which will inevitably lead to mutual interference between weather radars of different bands, and the large size and power consumption of the radar system. Compared with single-base weather radars, multi-base radars use different transmission and reception sites, with multiple transmitting stations and receiving stations, which are configured in a discrete form, which can effectively reduce the mutual interference between weather radars of different bands and reduce the complexity of the system. At the same time, it can also directly measure meteorological parameters such as reflectivity, vertical wind, eddy currents, and can further invert the relevant air pressure and temperature. It has obvious advantages.

[0005] However, multi-base radars still have serious problems in the distribution, transmission and processing of frequency reference signals. When using the global positioning system and two-way satellite frequency transmission method, the reference signal is easily interfered by the external environment. When using communication data link transmission, the high-frequency cable transmission loss is large, and the transmission distance is difficult to meet the demand. In addition, the size and price of high-frequency cables also make it difficult for multi-base radars to develop further. In order to solve the technical problems encountered by multi-base meteorological radars, new principles and methods need to be proposed. Summary of the invention

[0006] The purpose of the present invention is to provide a frequency mixing processing device and a processing method for a dual-band multi-base weather radar, which utilizes photonics to realize a dual-band, multi-base weather radar, so that the device can simultaneously measure different meteorological parameters, and the device has a simple structure and stable performance.

[0007] To achieve the above object, the present invention adopts the following technical solution:

[0008] A frequency mixing processing device for a dual-band multi-base weather radar comprises at least one local transmitting end device for modulating a local radio frequency reference signal into an optical domain, and at least two remote receiving devices matched with the local transmitting end device for modulating the optical domain into an optical signal again after being processed by an amplifier, which are respectively a first remote receiving device and a second remote receiving device.

[0009] Preferably, the local transmitting end device of the present invention comprises a laser, a first electro-optic modulator, a second electro-optic modulator, and an erbium-doped fiber amplifier connected in sequence, the radio frequency port of the first electro-optic modulator is connected to the local oscillator radio frequency signal source, the output signal of the erbium-doped fiber amplifier is injected into port 1 of the optical circulator, the output signal of port 2 of the optical circulator enters the Bragg grating, the Bragg grating reflection signal enters from port 2 of the optical circulator, and port 3 of the optical circulator is output to the first optical fiber link, the first optical fiber link is connected in sequence to the first optical fiber splitter, the first photoelectric detector, and the first radio frequency amplifier, and the output end of the first radio frequency amplifier is connected to the radio frequency port of the second electro-optic modulator; the transmission end of the Bragg grating is connected in sequence to the second optical fiber splitter, the fourth electro-optic modulator, the third photoelectric detector, the third radio frequency amplifier, and the second transmitting antenna, and the second pulse generator is connected to the radio frequency port of the fourth electro-optic modulator; one output of the first optical fiber splitter is connected in sequence to the third electro-optic modulator, the second photoelectric detector, the second radio frequency amplifier, and the first transmitting antenna, and the first pulse generator is connected to the radio frequency port of the third electro-optic modulator.

[0010] Preferably, in the first remote receiving device of the present invention, one output end of the first optical fiber splitter is connected in sequence to the second optical fiber link, the fifth electro-optical modulator, the fourth photodetector, the first filter, and the first signal processing unit, and the first receiving antenna, the fourth radio frequency amplifier and the radio frequency port of the fifth electro-optical modulator are connected.

[0011] Preferably, in the second remote receiving device of the present invention, one output end of the second optical fiber splitter is connected in sequence to the third optical fiber link, the sixth electro-optical modulator, the fifth photodetector, the second filter, and the second signal processing unit, and the second receiving antenna and the fifth radio frequency amplifier are connected to the radio frequency port of the sixth electro-optical modulator.

[0012] Based on the processing method of the mixing processing device of the present invention,

[0013] At the local transmitting end, the local oscillator RF signal source is injected into the first electro-optic modulator, the first electro-optic modulator for suppressing the optical carrier component and generating positive and negative first-order optical sideband signals works at the minimum bias point, the second electro-optic modulator, the erbium-doped fiber amplifier, the optical circulator, the first optical fiber link, the first optical fiber beam splitter, the first photoelectric detector and the first RF amplifier form an optoelectronic oscillation ring cavity structure, the working state of the second electro-optic modulator is controlled, the second electro-optic modulator works at the minimum bias point, the second electro-optic modulator outputs a four-tooth frequency comb signal, and the Bra The positive and negative first-order sideband signals are fed back into the optoelectronic oscillation ring cavity through grating filtering, and the positive and negative third-order sideband signals are injected into the second optical fiber beam splitter, so that the first optical fiber beam splitter carries the positive and negative first-order optical sideband signals, and the second optical fiber beam splitter carries the positive and negative third-order optical sideband signals. The signal generated by the pulse generator is modulated into the optical domain by the third electro-optic modulator and the fourth electro-optic modulator, and the signal is restored to double-frequency and sextuple-frequency RF signals in combination with the third photodetector and the fourth photodetector, and radiated into the air after amplification by the first transmitting antenna and the second transmitting antenna.

[0014] Preferably, in the processing method of the present invention, in the first remote receiving device, the first optical fiber splitter transmits the positive and negative first-order optical sideband signals to the fifth electro-optical modulator through the second optical fiber link, the first receiving antenna receives the doubled frequency signal, which is amplified by the fourth radio frequency amplifier and modulated to the positive and negative first-order optical sideband signals through the fifth electro-optical modulator, optical domain modulation and photoelectric detection realize signal down-conversion, and the recovered signal enters the first signal processing unit for processing.

[0015] Preferably, in the processing method of the present invention, in the second remote receiving device, the second optical fiber splitter transmits the positive and negative third-order optical sideband signals to the sixth electro-optical modulator through the third optical fiber link, the second receiving antenna receives the sextuple frequency signal, which is amplified by the fifth radio frequency amplifier and modulated to the positive and negative third-order optical sideband signals through the sixth electro-optical modulator, optical domain modulation and photoelectric detection realize signal down-conversion, and the recovered signal enters the second signal processing unit for processing.

[0016] The invention discloses a frequency mixing processing device and a processing method for a dual-band multi-base weather radar. The device for realizing the frequency mixing processing comprises a local transmitting end device and a remote receiving end device. Photonics technology is used to modulate a local end radio frequency reference signal into an optical domain, control the working state of an electro-optical modulator, and use an optoelectronic oscillation loop to multiply the frequency of the local end radio frequency signal while optimizing the phase noise performance of the signal. An optical sideband signal carrying double frequency and sextuple frequency components is transmitted through an optical fiber link. The local end uses an electro-optical modulator to modulate a pulse signal into an optical domain to realize frequency mixing modulation. The optical signal is restored to a radio frequency signal through a photoelectric detector, and the microwave signal is amplified and radiated through a local end transmitting antenna with different wavelengths. The remote receiving end signal returns to the ground through a receiving antenna, is processed by an amplifier and modulated to an optical signal again, and frequency mixing processing of the signal is realized in the optical domain. The dual-band, multi-base weather radar is realized by photonics. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a principle block diagram of a dual-band photonics multi-base weather radar apparatus and method.

[0018] The invention comprises: 1. a laser, 2. a first electro-optic modulator, 3. a second electro-optic modulator, 4. an erbium-doped fiber amplifier, 5. an optical circulator, 6. a Bragg grating, 7. a first optical fiber link, 8. a first optical fiber beam splitter, 9. a first photoelectric detector, 10. a first radio frequency amplifier, 11 a local oscillator radio frequency signal source, 12. a first pulse generator, 13. a third electro-optic modulator, 14 a second photoelectric detector, 15. a second radio frequency amplifier, 16. a first transmitting antenna, 17. a second optical fiber beam splitter, 18. a second pulse generator, 19 a fourth electro-optic modulator, 20 a second optical fiber beam splitter, 21 a second optical fiber beam splitter, 22 a second optical fiber beam splitter, 23 a second optical fiber beam splitter, 24 a second optical fiber beam splitter, 25 a second optical fiber beam splitter, 26 a second optical fiber beam splitter, 27 a second optical fiber beam splitter, 28 a second optical fiber beam splitter, 29 a first optical fiber beam splitter, 30 a first optical fiber beam splitter, 31 a first optical fiber beam splitter, 32 a first optical fiber beam splitter, 33 a first optical fiber beam splitter, 34 a second optical fiber beam splitter, 35 a second optical fiber beam splitter, 36 a first optical fiber beam splitter, 37 a first optical fiber beam splitter, 38 a second optical fiber beam splitter, 39 a first optical fiber beam splitter, 40 a first optical fiber beam splitter, 41 a first optical fiber beam splitter, 42 a first optical fiber beam splitter, 43 a first optical fiber beam splitter, 44 a first optical fiber beam splitter, 45 a first optical fiber beam splitter, 46 a first optical fiber beam splitter, 47 a first optical fiber beam splitter, 48 Optical modulator, 20, third photodetector, 21, third radio frequency amplifier, 22, second transmitting antenna, 23, first receiving antenna, 24, fourth radio frequency amplifier, 25, fifth electro-optic modulator, 26, second optical fiber link, 27, fourth photodetector, 28, first filter, 29, first signal processing unit, 30, second receiving antenna, 31, fifth radio frequency amplifier, 32, sixth electro-optic modulator, 33, third optical fiber link, 34, fifth photodetector, 35, second filter, 36, second signal processing unit. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is described in detail below with reference to the accompanying drawings:

[0020] like Figure 1 As shown, a frequency mixing processing device for a dual-band multi-base weather radar includes at least one local transmitting device for modulating a local radio frequency reference signal into an optical domain, and at least two remote receiving devices matched with the local transmitting device for modulating the optical domain into an optical signal again after processing through an amplifier.

[0021] like Figure 1 As shown, the local transmitting end device of the present invention comprises a laser 1, a first electro-optic modulator 2, a second electro-optic modulator 3, and an erbium-doped fiber amplifier 4 which are connected in sequence. The radio frequency port of the first electro-optic modulator 2 is connected to a local oscillator radio frequency signal source 11. The output signal of the erbium-doped fiber amplifier 4 is injected into the port 1 of the optical circulator 5. The output signal of the port 2 of the optical circulator 5 enters the Bragg grating 6. The reflected signal of the Bragg grating 6 enters from the port 2 of the optical circulator 5. The port 3 of the optical circulator 5 outputs to the first optical fiber link 7. The first optical fiber link 7 is connected in sequence to the first optical fiber beam splitter 8, the first photoelectric detector 9, and the first radio frequency amplifier 10. The output end of the first RF amplifier 10 is connected to the RF port of the second electro-optical modulator 3; the transmission end of the Bragg grating 6 is connected to the second optical fiber splitter 17, the fourth electro-optical modulator 19, the third photodetector 20, the third RF amplifier 21, and the second transmitting antenna 22 in sequence, and the second pulse generator 18 is connected to the RF port of the fourth electro-optical modulator 19; one output of the first optical fiber splitter 8 is connected to the third electro-optical modulator 13, the second photodetector 14, the second RF amplifier 15, and the first transmitting antenna 16 in sequence, and the first pulse generator 12 is connected to the RF port of the third electro-optical modulator 13.

[0022] like Figure 1 As shown, in the first remote receiving device of the present invention, one output end of the first optical fiber splitter 8 is connected in sequence to the second optical fiber link 26, the fifth electro-optical modulator 25, the fourth photodetector 27, the first filter 28, and the first signal processing unit 29, and the first receiving antenna 23 and the fourth RF amplifier 24 are connected to the RF port of the fifth electro-optical modulator 25.

[0023] like Figure 1 As shown, in the second remote receiving device of the present invention, one output end of the second optical fiber splitter 17 is connected in sequence to the third optical fiber link 33, the sixth electro-optical modulator 32, the fifth photodetector 34, the second filter 35, and the second signal processing unit 36, and the second receiving antenna 30 and the fifth RF amplifier 31 are connected to the RF port of the sixth electro-optical modulator 32.

[0024] Based on the processing method of the mixing processing device of the present invention,

[0025] At the local transmitting end, the local oscillator RF signal source 11 is injected into the first electro-optic modulator 2, which is used to suppress the optical carrier component and generate positive and negative first-order optical sideband signals. The first electro-optic modulator 2 works at the minimum bias point. The second electro-optic modulator 3, the erbium-doped fiber amplifier 4, the optical circulator 5, the first optical fiber link 7, the first optical fiber beam splitter 8, the first photodetector 9 and the first RF amplifier 10 form an optoelectronic oscillation ring cavity structure, which controls the working state of the second electro-optic modulator 3 so that the second electro-optic modulator 3 works at the minimum bias point. The second electro-optic modulator 3 outputs a four-tooth frequency comb signal, and uses the Bragg oscillator to generate a four-tooth frequency comb signal. The grating 6 filters and feeds the positive and negative first-order sideband signals back into the optoelectronic oscillation ring cavity, and the positive and negative third-order sideband signals are injected into the second optical fiber splitter 17, so that the first optical fiber splitter 8 carries the positive and negative first-order optical sideband signals, and the second optical fiber splitter 17 carries the positive and negative third-order optical sideband signals. The signal generated by the pulse generator is modulated into the optical domain by the third electro-optical modulator 13 and the fourth electro-optical modulator 19, and the signal is restored to the doubled frequency and the sextuple frequency RF signal in combination with the third photodetector 20 and the fourth photodetector 27, and then radiated into the air by the first transmitting antenna 16 and the second transmitting antenna 22 after amplification.

[0026] In the first remote receiving device, the first optical fiber splitter 8 transmits the positive and negative first-order optical sideband signals to the fifth electro-optical modulator 25 through the second optical fiber link 26. The first receiving antenna 23 receives the doubled frequency signal, which is amplified by the fourth RF amplifier 24 and modulated to the positive and negative first-order optical sideband signals through the fifth electro-optical modulator 25. Optical domain modulation and photoelectric detection realize signal down-conversion, and the recovered signal enters the first signal processing unit 29 for processing.

[0027] In the second remote receiving device, the second optical fiber splitter 17 transmits the positive and negative third-order optical sideband signals to the sixth electro-optical modulator 32 through the third optical fiber link 33. The second receiving antenna 30 receives the six-fold frequency signal, which is amplified by the fifth RF amplifier 31 and modulated to the positive and negative third-order optical sideband signals through the sixth electro-optical modulator 32. Optical domain modulation and photoelectric detection realize signal down-conversion, and the recovered signal enters the second signal processing unit 36 ​​for processing.

[0028] The laser 1 of the present invention adopts a narrow line width semiconductor laser, the first electro-optic modulator 2, the second electro-optic modulator 3, the third electro-optic modulator 13, the fourth electro-optic modulator 19, the fifth electro-optic modulator 25, and the sixth electro-optic modulator 32 adopt Mach-Zehnder double-arm structure electro-optic intensity modulators; the erbium-doped fiber amplifier 4 adopts an erbium-doped fiber amplifier with an output optical power greater than 30 dBm; the optical circulator 5 adopts a 1-input 2-output or 2-input 3-output structure; the Bragg grating 6 adopts an equally spaced linear Bragg grating; the first optical fiber link 7, the second optical fiber link 26, and the third optical fiber link 33 adopt G.652 or G.655 optical fiber; the first optical fiber beam splitter 8 and the second optical fiber beam splitter 17 adopt a 1×3 optical coupler; the first photoelectric detection The device 9, the second photodetector 14, the third photodetector 20, the fourth photodetector 27, and the fifth photodetector 34 use PIN photodetection components; the first RF amplifier 10, the second RF amplifier 15, the third RF amplifier 21, the fourth RF amplifier 24, and the fifth RF amplifier 31 use bandpass amplifiers; the first pulse generator 12 and the second pulse generator 18 use arbitrary waveform generators; the first transmitting antenna 16 and the first receiving antenna 23 have the same operating frequency band; the second transmitting antenna 22 and the second receiving antenna 30 have the same operating frequency band; the first signal processing unit 29 and the second signal processing unit 36 ​​use radar signal processing modules; the first filter 28 and the second filter 35 use low-pass filters.

[0029] Multi-base radar can effectively reduce the mutual interference of weather radars of different bands and reduce the complexity of the system. At the same time, it can also directly measure meteorological parameters such as reflectivity, vertical wind, eddy current, and further invert the relevant air pressure and temperature. However, multi-base radar still has serious problems in the distribution, transmission and processing of frequency reference signals. The reference signal is easily interfered by the external environment when using the global positioning system and the two-way satellite frequency transmission method. When using the communication data link transmission, the high-frequency cable transmission loss is large, and the transmission distance is difficult to meet the demand. In addition, the volume and price of the high-frequency cable also make it difficult for multi-base radar to develop further. In order to solve the technical problems encountered by multi-base weather radar, the present invention proposes a new processing device and processing method.

Claims

1. A frequency mixing processing device for a dual-band multi-base weather radar, characterized in that It includes at least one local transmitting end device for modulating a local end radio frequency reference signal into an optical domain, and at least two remote receiving devices matched with the local transmitting end device for modulating the optical domain into an optical signal again after being processed by an amplifier, which are respectively a first remote receiving device and a second remote receiving device; The local transmitting end device comprises a laser (1), a first electro-optical modulator (2), a second electro-optical modulator (3), and an erbium-doped fiber amplifier (4) connected in sequence. The radio frequency port of the first electro-optical modulator (2) is connected to a local oscillator radio frequency signal source (11). The output signal of the erbium-doped fiber amplifier (4) is injected into port 1 of an optical circulator (5). The output signal of port 2 of the optical circulator (5) enters a Bragg grating (6). The reflected signal of the Bragg grating (6) enters from port 2 of the optical circulator (5). Port 3 of the optical circulator (5) outputs to a first optical fiber link (7). The first optical fiber link (7) is connected in sequence to a first optical fiber beam splitter (8), a first photoelectric detector (9), and a first radio frequency amplifier (10). The output end of the first radio frequency amplifier (10) is connected to the radio frequency port of the second electro-optic modulator (3); the transmission end of the Bragg grating (6) is connected to the second optical fiber beam splitter (17), the fourth electro-optic modulator (19), the third photoelectric detector (20), the third radio frequency amplifier (21), and the second transmitting antenna (22) in sequence, and the second pulse generator (18) is connected to the radio frequency port of the fourth electro-optic modulator (19); one output of the first optical fiber beam splitter (8) is connected to the third electro-optic modulator (13), the second photoelectric detector (14), the second radio frequency amplifier (15), and the first transmitting antenna (16) in sequence, and the first pulse generator (12) is connected to the radio frequency port of the third electro-optic modulator (13).

2. The frequency mixing processing device for dual-band multi-base weather radar according to claim 1, characterized in that In the above-mentioned first remote receiving device, one output end of the first optical fiber splitter (8) is connected to the second optical fiber link (26), the fifth electro-optical modulator (25), the fourth photodetector (27), the first filter (28), and the first signal processing unit (29) in sequence, and the first receiving antenna (23) and the fourth radio frequency amplifier (24) are connected to the radio frequency port of the fifth electro-optical modulator (25).

3. The frequency mixing processing device for dual-band multi-base weather radar according to claim 1, characterized in that In the above-mentioned second remote receiving device, one output end of the second optical fiber splitter (17) is connected in sequence to the third optical fiber link (33), the sixth electro-optical modulator (32), the fifth photodetector (34), the second filter (35), and the second signal processing unit (36), and the second receiving antenna (30) and the fifth radio frequency amplifier (31) are connected to the radio frequency port of the sixth electro-optical modulator (32).

4. A processing method based on the frequency mixing processing device according to any one of claims 1 to 3, characterized in that: At the local transmitting end, a local oscillator radio frequency signal source (11) is injected into the first electro-optic modulator (2), the first electro-optic modulator (2) for suppressing the optical carrier component and generating positive and negative first-order optical sideband signals operates at a minimum bias point, the second electro-optic modulator (3), the erbium-doped fiber amplifier (4), the optical circulator (5), the first optical fiber link (7), the first optical fiber beam splitter (8), the first photoelectric detector (9) and the first radio frequency amplifier (10) form an optoelectronic oscillation ring cavity structure, the working state of the second electro-optic modulator (3) is controlled, the second electro-optic modulator (3) operates at a minimum bias point, the second electro-optic modulator (3) outputs a four-tooth frequency comb signal, and the optical fiber amplifier (4) is used to generate a first optical fiber signal. The optical fiber is filtered by a Bragg grating (6), and the positive and negative first-order sideband signals are fed back into the photoelectric oscillation ring cavity. The positive and negative third-order sideband signals are injected into the second optical fiber beam splitter (17), so that the first optical fiber beam splitter (8) carries the positive and negative first-order optical sideband signals, and the second optical fiber beam splitter (17) carries the positive and negative third-order optical sideband signals. The signal generated by the pulse generator is modulated into the optical domain by using a third electro-optical modulator (13) and a fourth electro-optical modulator (19). The signal is restored to a double frequency and a sextuple frequency radio frequency signal in combination with a third photodetector (20) and a fourth photodetector (27), and after amplification, the signal is radiated into the air by using a first transmitting antenna (16) and a second transmitting antenna (22).

5. The processing method according to claim 4, characterized in that: In the first remote receiving device, the first optical fiber splitter (8) transmits the positive and negative first-order optical sideband signals to the fifth electro-optical modulator (25) through the second optical fiber link (26), the first receiving antenna (23) receives the doubled frequency signal, which is amplified by the fourth radio frequency amplifier (24) and modulated to the positive and negative first-order optical sideband signals through the fifth electro-optical modulator (25), the optical domain modulation and photoelectric detection realize signal down-conversion, and the recovered signal enters the first signal processing unit (29) for processing.

6. The processing method according to claim 4, characterized in that: In the second remote receiving device, the second optical fiber splitter (17) transmits the positive and negative third-order optical sideband signals to the sixth electro-optical modulator (32) through the third optical fiber link (33), the second receiving antenna (30) receives the sextuple frequency signal, which is amplified by the fifth radio frequency amplifier (31) and modulated to the positive and negative third-order optical sideband signals through the sixth electro-optical modulator (32), the optical domain modulation and photoelectric detection realize signal down-conversion, and the recovered signal enters the second signal processing unit (36) for processing.

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