Microwave photon wind measurement radar device

Abstract

This invention discloses a microwave photonic wind radar device. It uses an optoelectronic oscillator as a frequency source to generate a low-phase-noise radio frequency signal. A circulator and a four-beam antenna are used to achieve shared transmitting and receiving antennas, reducing antenna size while enabling accurate measurement of small-scale atmospheric turbulence. A comprehensive processing module controls a high-isolation switching module and the timing of the receiving control switch, and the four-beam antenna is used to measure radial wind speed in four directions, thereby calculating wind direction information. The device has a smaller antenna size, and the low-phase-noise radio frequency signal has stronger penetration in adverse weather conditions, effectively compensating for the inability of lidar to operate in inclement weather.

Description

Technical Field

[0001] This invention relates to the fields of microwave signal detection and weather radar technology, and in particular to a microwave photonic radar wind measurement device for detecting electromagnetic wave scattering in near-range atmospheric turbulence. Background Technology

[0002] Wind profiler radar, as a ballless upper-air meteorological detection device, is an important supplement to conventional sounding, continuously providing the distribution of meteorological elements such as atmospheric velocity, temperature, and refractive index structure constant with altitude. The data provided by wind profiler radar has high spatiotemporal resolution, good continuity, and real-time performance. Wind profiler radar typically transmits electromagnetic beams vertically into the upper atmosphere through a phased array antenna, detecting changes in electromagnetic wave scattering signals caused by refractive index fluctuations due to atmospheric turbulence, thereby estimating information such as wind speed and direction at the location of the echo signal.

[0003] Wind profiler radar plays an irreplaceable role in atmospheric science research, meteorological operational applications, and social meteorological services. In particular, it can be used to study atmospheric turbulence and the atmospheric boundary layer, infer the turbulent structure of atmospheric motion, detect changes in the atmospheric boundary layer, and determine the location and height of wind shear.

[0004] In recent years, there has been an urgent need for wind field resource measurement and wind turbine nacelle forward wind field measurement. Compared with traditional meteorological operations, wind field resource measurement and wind turbine nacelle forward wind field measurement target small-scale meteorological measurements within a few hundred meters. Currently, wind profiler radars are mostly used to detect atmospheric scattering in the boundary layer and stratosphere, targeting larger-scale meteorological phenomena. However, for small-scale meteorological detection, wind profiler radars are too large and too expensive. Small-scale turbulence measurement usually uses lidar, but lidar is easily affected by severe weather and may become inoperable. In recent years, 24GHz microwave radar has also been used for near-field turbulence measurement, but traditional microwave oscillator frequency sources struggle to simultaneously achieve the characteristics of high oscillation frequency and high Q value of the resonant cavity. This results in poor noise performance of the directly generated high-frequency microwave signal, making the measurement accuracy highly susceptible to the phase noise of the frequency source. Summary of the Invention

[0005] The main objective of this invention is to provide a microwave photonic wind radar device that uses a photoelectric oscillator to generate microwave signals to achieve accurate measurement of small-scale near-field atmospheric turbulence in all weather conditions.

[0006] The technical solution adopted in this invention is:

[0007] A microwave photonic wind measurement radar device is provided, including...

[0008] An optoelectronic oscillator is used to generate a low-phase-noise continuous radio frequency signal and output it to a three-terminal circulator.

[0009] The four-beam antenna, under the control of the integrated processing module, enables the transmission of radio frequency signals and the reception of reflected signals in the four directions of east, west, south, and north.

[0010] The three-terminal circulator includes three ports. It receives continuous radio frequency signals through port a, sends them to a four-beam antenna through port b, receives signals from the four-beam antenna through port b, and then outputs the received signals through port c.

[0011] The high-isolation switching module uses two single-pole single-throw switches connected in series, which operate synchronously under the control of the integrated processing module, achieving pulsed continuous signals with high isolation.

[0012] The receiving control switch adopts a single-pole single-throw switch, which realizes time-division controlled reception of four-beam antenna signals under the control of the integrated processing module;

[0013] The integrated processing module enables controlled transmission of radio frequency signals, controlled reception of antenna signals, and data processing.

[0014] According to the above technical solution, the optoelectronic oscillator includes a laser, a Mach-Zehnder modulator, a photodetector, an amplifier, a bandpass filter, and a microwave coupler connected in sequence; and one output terminal of the microwave coupler is also connected to one input terminal of the Mach-Zehnder modulator.

[0015] The continuous laser emitted by the laser enters the Mach-Zehnder modulator for modulation, and then enters the photodetector through a long optical fiber to convert the optical signal into an electrical signal. The electrical signal passes through an amplifier and a bandpass filter and then enters the microwave coupler to generate a low-phase-noise continuous radio frequency signal. At the same time, the microwave coupler generates a feedback signal to the Mach-Zehnder modulator to modulate the continuous laser emitted by the laser.

[0016] According to the above technical solution, the four-beam antenna includes a single-pole four-throw switch, four sets of feed sources and a parabolic reflector. The four sets of feed sources are connected to the output of the single-pole four-throw switch respectively, and the center of the four sets of feed sources generates beam deflection at the intersection of the parabolic reflector, so that the four beams are deflected by θ in the four directions of east, south, west and north relative to the normal direction, and 10°≤θ≤45°.

[0017] Following the above technical solution, the isolation of the three-terminal circulator is ≥20dB, and the insertion loss is ≤1dB.

[0018] Following the above technical solution, the power divider is a power divider that adopts a microstrip current structure.

[0019] According to the above technical solution, the mixer is composed of a single-ended to differential amplifier circuit and a low-pass filter circuit connected in series. The single-ended to differential amplifier circuit converts the single-ended input signal into a differential signal and amplifies it. The differential signal enters the low-pass filter circuit to filter out noise from the differential signal.

[0020] Following the above technical solution, the output of the optoelectronic oscillator is 77.000 GHz ± 1 kHz, with phase noise ≤ 144 dBc / Hz @ 10 kHz and frequency stability ≤ 10. -10 @1s radio frequency signal.

[0021] Following the above technical solution, the gain of the four-beam antenna is ≥28dB, and the sidelobe attenuation is ≤-20dB.

[0022] Following the above technical solution, the saturation power of the power amplifier is not less than 40dBm, and the gain is not less than 25dB.

[0023] According to the above technical solution, the pre-amplifier has a noise figure of no more than 2.5, and the post-amplifier has a gain of no less than 40dB, and is composed of multiple stages of low noise amplifiers.

[0024] The present invention also provides a measurement method for microwave photonic wind measuring radar, which is based on the microwave photonic wind measuring radar device described above, and specifically includes the following steps:

[0025] The continuous radio frequency signal generated by the opto-oscillator is divided into a measurement signal and a reference signal by a power divider, and the reference signal is input into a mixer.

[0026] The measurement signal enters the high-isolation switching module, and is converted into an RF pulse signal under the control of the integrated processing module;

[0027] The radio frequency pulse signal is input from port a of the three-terminal circulator after passing through the power amplifier, and then output to the four-beam antenna through port b. The reflected signal received by the four-beam antenna is input from port b and then output from port c to the receive control switch to form a reflected receive signal.

[0028] The reflected received signal passes through a pre-amplifier, an RF bandpass filter, a digitally controlled attenuator, and a post-amplifier before entering the mixer, where it is mixed with the reference signal to form an intermediate frequency signal.

[0029] After passing through the intermediate frequency processing circuit, the intermediate frequency signal is converted into an analog-to-digital converter, digitized, and then processed by the integrated processing module to finally calculate the wind speed and wind direction information.

[0030] The beneficial effects of this invention are as follows: This invention provides a microwave photonic wind radar device that combines microwave photonic technology with wind radar technology. It uses an optoelectronic oscillator to generate a low-phase-noise continuous radio frequency signal and uses a circulator and a four-beam antenna to achieve shared transmitting and receiving antennas, thereby enabling accurate measurement of near-field small-scale atmospheric turbulence in all weather conditions.

[0031] Furthermore, the device of the present invention has a smaller antenna size and stronger penetration in the 77.000GHz band under adverse weather conditions, effectively compensating for the problem that lidar cannot work in adverse weather conditions. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a block diagram of the microwave photonic wind measuring radar device according to an embodiment of the present invention;

[0034] Figure 2 This is a timing control diagram of the high isolation switching module and the receiving control switch according to an embodiment of the present invention;

[0035] Figure 3 This is a block diagram of the photoelectric oscillator according to an embodiment of the present invention;

[0036] Figure 4 This is a schematic diagram of the four-beam antenna configuration according to an embodiment of the present invention;

[0037] Figure 5 This is a pointing diagram of a four-beam antenna according to an embodiment of the present invention. Detailed Implementation

[0038] 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.

[0039] This invention utilizes an optoelectronic oscillator to generate a 77.000 GHz radio frequency signal and uses a circulator and a four-beam antenna to achieve shared transmitting and receiving antennas, enabling accurate measurement of near-field small-scale atmospheric turbulence in all weather conditions and significantly reducing the overall size of the device.

[0040] This invention provides a microwave photonic wind measurement radar device, comprising:

[0041] The optoelectronic oscillator 1 generates a low-phase-noise continuous radio frequency signal with an output frequency of 77.000 GHz, which is shorter than the wavelength of traditional microwave wind measuring radar, resulting in a smaller antenna size. This band has stronger penetration in adverse weather conditions, effectively compensating for the problem that lidar cannot work in adverse weather conditions. At the same time, the radio frequency output signal of the optoelectronic oscillator 1 has low phase noise and small time jitter, resulting in higher measurement accuracy compared to traditional microwave wind measuring radar.

[0042] The four-beam antenna 6, under the control of the integrated processing module, enables the transmission of radio frequency signals and the reception of reflected signals in the four directions (north, south, east, and west), thereby achieving the measurement of radial wind speed in the four directions.

[0043] The three-terminal circulator 5 sends the RF signal from port a to the four-beam antenna via port b, receives the signal from the four-beam antenna via port b, and then outputs the received signal via port c. In this embodiment of the invention, the circulator 5 achieves a shared antenna for the transmit and receive links. The circulator 5 has three ports, with the signal flow direction being input from port a and output from port b; the signal input from port b exits from port c. The circulator isolation is not less than 20 dB, and the insertion loss is not greater than 1 dB.

[0044] The high-isolation switch module 3 uses two single-pole single-throw switches connected in series with high-level conduction. Under the control of the integrated processing module, they operate synchronously to realize the pulsed generation of continuous signals with high isolation.

[0045] The receiver control switch 7 is a single-pole single-throw switch that turns off at a high level, and under the control of the integrated processing module, it realizes time-division controlled reception of four-beam antenna signals.

[0046] The integrated processing module 15 realizes controlled transmission of radio frequency signals, controlled reception of antenna signals, and data processing. The integrated processing module 15 strictly controls the conduction timing of the high isolation switch module 3 and the receiving control switch 7 to realize the transmission and reception of signals in four directions of the four-beam antenna 6, with the transmitting antenna being shared.

[0047] like Figure 1 As shown, the working principle of the microwave photonic wind radar device is as follows:

[0048] The continuous radio frequency signal generated by the opto-oscillator 1 is divided into a measurement signal and a reference signal by the power divider 2. The reference signal is input to the mixer 12. The measurement signal enters the high isolation switch module 3 and is formed into a radio frequency pulse signal under the control of the integrated processing module 15. The radio frequency pulse signal is input from port a of the three-terminal circulator 5 after passing through the power amplifier 4, and then output to the four-beam antenna 6 through port b. The reflected signal received by the four-beam antenna 6 is input from port b and then output from port c to the receiving control switch 7 to form a reflected reception signal. The integrated processing module 15 controls the four-beam antenna 6 to perform sequential beam switching every 0.25s, so that the radio frequency pulse is transmitted sequentially in four orthogonal directions. The transmitted radio frequency pulse is scattered by atmospheric turbulence, and the scattered signal is received by the four-beam antenna 6 to form a turbulent scattered radio frequency pulse, i.e., a reflected reception signal.

[0049] The reflected received signal passes through a pre-amplifier 8, an RF bandpass filter 9, and a digitally controlled attenuator 10. Under the control of the integrated processing module 15, the turbulent scattered echoes at different distances after spurious filtering are attenuated in a programmed manner to reduce the dynamic range of the turbulent scattered echo signal. The signal undergoing programmed attenuation enters a post-amplifier 11 for amplification and then enters a mixer 12 to be mixed with a reference signal to form an intermediate frequency signal (two orthogonal IQ signals). The intermediate frequency signal is then processed by an intermediate frequency processing circuit 13 for low-frequency filtering and amplification to match the input range of the analog-to-digital converter 14. After being digitized by the analog-to-digital converter 14, it enters the integrated processing module 15 for processing and storage. The radial wind speed pointing downwards from the current beam is calculated, and then the wind speed and wind direction information are calculated based on the radial wind speeds in the four directions.

[0050] In this embodiment of the invention, the intermediate frequency processing circuit 13 consists of two stages. The first stage is a single-ended to differential amplifier circuit, which converts the signal input from the mixer 12 into a differential signal and amplifies it. The second stage is a low-pass filter circuit, which filters out noise from the differential signal.

[0051] This invention uses a comprehensive processing module 15 to strictly control the conduction timing of the high-isolation switch module 3 and the receive control switch 7, enabling the transmission and reception of signals from the four-beam antenna 6 in all four directions, with the transmitting antenna sharing the same signal. The receive control switch 7 is turned off when the high-isolation switch module 3 is on, to prevent radio frequency signals in the transmit link from being coupled into the receive link by the circulator, which could lead to saturation or damage to the receive link devices.

[0052] The control timing of the high isolation switch module 3 and the receiving control switch 7 is as follows: Figure 2 As shown, the two single-pole single-throw switches in the high-isolation switch module 3 operate synchronously when the high-level conduction is active, with an on-cycle of 250kHz and an on-time of 200ns. The receive control switch 7 has an off-cycle of 250kHz and an off-time of 250ns, which is 50ns longer than the on-time of the high-isolation switch module 3 to avoid power coupling introduced by the switching delay.

[0053] As a preferred embodiment, such as Figure 3 As shown, the internal structure and principle of the photoelectric oscillator 1 are as follows:

[0054] The continuous laser emitted by laser 101 is modulated by Mach-Zehnder modulator 102, then passes through long optical fiber 103 and enters photodetector 104 to convert the optical signal into an electrical signal. This electrical signal passes through amplifier 105 and bandpass filter 106 before entering microwave coupler 107 to generate a low-phase-noise 77GHz continuous radio frequency signal. Simultaneously, microwave coupler 107 generates a feedback signal to Mach-Zehnder modulator 102 to modulate the continuous laser emitted by laser 101. The signal undergoes continuous photoelectric conversion, amplification, and feedback in the loop, ultimately achieving stable self-oscillation before being output from microwave coupler 107.

[0055] By using electro-optical to photoelectric conversion, a kilometer-long optical fiber 103 is used as part of the resonant cavity. Relying on the advantages of low loss and large bandwidth of optical fiber, the constructed photoelectric resonant cavity has an ultra-high Q value and can generate high-frequency microwave signals with ultra-low phase noise.

[0056] As a preferred embodiment, such as Figure 4 As shown, the four-beam antenna 6 includes a single-pole four-throw switch 601, four sets of feed sources 602, and a parabolic reflector 603. The four sets of feed sources 602 are connected to the outputs of the single-pole four-throw switch 601, and the centers of the four sets of feed sources 602 generate beam deflection at the intersection of the parabolic reflector 603, causing the four beams to be deflected by θ in the four directions of east, south, west, and north relative to the normal direction, with 10°≤θ≤45°. As a preferred embodiment, such as... Figure 5 As shown, the four beams are deflected by 15° in the four directions of southeast, northwest, and northeast relative to the normal direction.

[0057] In a preferred embodiment, the isolation of the three-terminal circulator 5 is ≥20dB, and the insertion loss is ≤1dB.

[0058] As a preferred embodiment, the power divider 2 is a power divider with a microstrip current structure, which has the characteristics of simple and compact structure, low cost, stable performance and wide bandwidth.

[0059] In a preferred embodiment, the mixer 12 is composed of a single-ended to differential amplifier circuit and a low-pass filter circuit connected in series. The single-ended to differential amplifier circuit converts the single-ended input signal into a differential signal and amplifies it. The differential signal enters the low-pass filter circuit to filter out noise from the differential signal.

[0060] In a preferred embodiment, the output of the photoelectric oscillator 1 is 77.000 GHz ± 1 kHz, with phase noise ≤ 144 dBc / Hz @ 10 kHz and frequency stability ≤ 10. -10 The radio frequency signal is 1 second. Using a 77 GHz radio frequency, the size is smaller than that of VHF (Very High Frequency) radar, UHF (Ultra High Frequency) radar, L-band radar, and 24 GHz radar while producing the same antenna gain, which is beneficial for miniaturization design.

[0061] In a preferred embodiment, the four-beam antenna 6 has a gain ≥28dB and a sidelobe attenuation ≤-20dB.

[0062] In a preferred embodiment, the saturation power of the power amplifier 4 is not less than 40dBm and the gain is not less than 25dB.

[0063] In a preferred embodiment, the preamplifier 8 has a noise figure of no more than 2.5, and the postamplifier 11 has a gain of no less than 40dB, and is composed of multiple stages of low noise amplifiers.

[0064] The device in this embodiment of the invention employs a shared transmit and receive antenna design, which significantly reduces the overall system size. However, to ensure transmit and receive isolation, additional switching devices are required. The introduction of these switching devices increases the insertion loss of the link, leading to a decrease in the system's receiving sensitivity. To compensate for the decrease in receiving sensitivity, the transmit power needs to be increased. However, increasing the transmit power places higher demands on transmit and receive isolation. Therefore, the magnitude of the increase in transmit power and the transmit and receive isolation need to be considered comprehensively.

[0065] As a preferred embodiment, the transmit power is 38dBm. When increasing the transmit power, it is necessary to ensure that the three-terminal circulator 5 and the high isolation switch module 3 at the back end of the power amplifier 4 can work normally. The three-terminal circulator 5 is designed with a maximum input power of 40dBm, and the single-pole four-throw switch 601 in the four-beam antenna 6 has a maximum input power of 39dBm, which can withstand the increase in transmit power.

[0066] During transmission, the power amplifier 4 outputs 38dBm, and the three-terminal circulator 5 has an isolation of approximately 20dB, resulting in an isolated output power of approximately 18dBm. The receiver control switch 7 uses a single-pole single-throw switch with an isolation of 40dB. After passing through the receiver control switch 7, the power is approximately -22dBm, which is completely lower than the input saturation power of the preamplifier low-noise amplifier 8, ensuring the isolation requirements during transmission.

[0067] When not transmitting, it is necessary to prevent power leakage from causing excessive receiver signal strength, which would affect the extraction of weak turbulent echo signals. During non-transmitting periods, the main influence is from the frequency source. The power output from power divider 2 to the pre-stage single-pole single-throw switch of high-isolation switching module 3 is +15dBm. After two stages of single-pole single-throw switches, the signal power attenuates to -65dBm. After being amplified by power amplifier 4 by 25dB, it reaches approximately -40dBm. Further attenuation by three-terminal circulator 5 (20dB) and receiver control switch 7 (40dB) results in a signal power of approximately -100dBm, close to the minimum receive power value of the receiving channel. Therefore, its impact on the actual echo signal is negligible.

[0068] In a preferred embodiment of the present invention, a 77 GHz radio frequency is used. Under the condition of producing the same antenna gain, the size is smaller than that of VHF (Very High Frequency) radar, UHF (Ultra High Frequency) radar, L-band radar, and 24 GHz radar, which is beneficial for miniaturization design.

[0069] It should be noted that, depending on the implementation needs, the various steps / components described in this application can be broken down into more steps / components, or two or more steps / components or parts of the operation of steps / components can be combined into new steps / components to achieve the purpose of this invention.

[0070] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A microwave photonic wind measurement radar device, characterized in that, include: An optoelectronic oscillator is used to generate a low-phase-noise continuous radio frequency signal and output it to a three-terminal circulator. The four-beam antenna, under the control of the integrated processing module, enables the transmission of radio frequency signals and the reception of reflected signals in the four directions of east, west, south, and north. The three-terminal circulator includes three ports. It receives a continuous radio frequency signal through port a, sends it to a four-beam antenna through port b, receives the signal from the four-beam antenna through port b, and then outputs the received signal through port c. The high-isolation switching module uses two single-pole single-throw switches connected in series, which operate synchronously under the control of the integrated processing module, achieving pulsed continuous signals with high isolation. The receiving control switch uses a single-pole single-throw switch to achieve time-division controlled reception of four-beam antenna signals under the control of the integrated processing module. The reflected received signal passes through a pre-amplifier, an RF bandpass filter, a digitally controlled attenuator, and a post-amplifier before entering the mixer. Specifically, the pre-amplifier and RF bandpass filter remove spurious signals from the reflected received signal. Then, under the control of the integrated processing module, the digitally controlled attenuator attenuates the turbulent scattered echoes at different distances after spurious filtering to reduce the dynamic range of the turbulent scattered echo signal. The attenuated signal enters the post-amplifier for amplification, and then enters the mixer to mix with the reference signal to form an intermediate frequency (IF) signal. The IF signal undergoes low-frequency filtering and amplification in the IF processing circuit to match the input range of the analog-to-digital converter (ADC). Finally, it is digitized by the ADC and enters the integrated processing module. The integrated processing module enables controlled transmission of radio frequency signals, controlled reception of antenna signals, and data processing, and calculates wind speed and wind direction information.

2. The microwave photonics wind lidar device of claim 1, wherein, The optoelectronic oscillator includes a laser, a Mach-Zehnder modulator, a photodetector, an amplifier, a bandpass filter, and a microwave coupler connected in sequence; and one output terminal of the microwave coupler is also connected to one input terminal of the Mach-Zehnder modulator. The continuous laser emitted by the laser enters the Mach-Zehnder modulator for modulation, and then enters the photodetector through a long optical fiber to convert the optical signal into an electrical signal. The electrical signal passes through an amplifier and a bandpass filter and then enters the microwave coupler to generate a low-phase-noise continuous radio frequency signal. At the same time, the microwave coupler generates a feedback signal to the Mach-Zehnder modulator to modulate the continuous laser emitted by the laser.

3. The microwave photonics wind lidar device of claim 1, wherein, The four-beam antenna includes a single-pole four-throw switch, four sets of feed sources, and a parabolic reflector. The four sets of feed sources are connected to the outputs of the single-pole four-throw switch, and the centers of the four sets of feed sources generate beam deflection at the intersection of the parabolic reflector, causing the four beams to deflect relative to the normal direction in the four cardinal directions (north, south, east, and west). And 10° .

4. The microwave photonics wind lidar device of claim 1, wherein, The isolation of the tri- port circulator , insertion loss .

5. The microwave photonics wind lidar device of claim 1, wherein, The mixer is composed of a single-ended to differential amplifier circuit and a low-pass filter circuit connected in series. The single-ended to differential amplifier circuit converts the single-ended input signal into a differential signal and amplifies it. The differential signal enters the low-pass filter circuit to filter out noise from the differential signal.

6. The microwave photonics wind lidar device of claim 2, wherein, The output of the photoelectric oscillator is 77.000 GHz ± 1 kHz, with phase noise ≤ 144 dBc / Hz @ 10 kHz and frequency stability ≤ 10. -10 @1s radio frequency signal.

7. The microwave photonics wind lidar device of claim 3, wherein, The gain of the four-beam antenna Sidelobe attenuation The saturation power of the power amplifier is not less than The gain should be no less than 25dB.

8. The microwave photonic wind radar device according to claim 3, characterized in that, The preamplifier has a noise figure of no more than 2.5, and the postamplifier has a gain of no less than 40dB, and is composed of multiple stages of low-noise amplifiers.

9. A measurement method of a microwave photon wind-radar, characterized by, This measurement method, based on the microwave photonic wind radar device according to any one of claims 1-8, specifically includes the following steps: The continuous radio frequency signal generated by the opto-oscillator is divided into a measurement signal and a reference signal by a power divider, and the reference signal is input into a mixer. The measurement signal enters the high-isolation switching module, and is converted into an RF pulse signal under the control of the integrated processing module; The radio frequency pulse signal is input from port a of the three-terminal circulator after passing through the power amplifier, and then output to the four-beam antenna through port b. The reflected signal received by the four-beam antenna is input from port b and then output from port c to the receive control switch to form a reflected receive signal. The reflected received signal passes through a pre-amplifier, an RF bandpass filter, a digitally controlled attenuator, and a post-amplifier before entering the mixer. Specifically, the pre-amplifier and RF bandpass filter remove spurious signals from the reflected received signal. Then, under the control of the integrated processing module, the digitally controlled attenuator attenuates the turbulent scattered echoes at different distances after spurious filtering to reduce the dynamic range of the turbulent scattered echo signal. The attenuated signal then enters the post-amplifier for amplification, and then enters the mixer to mix with the reference signal to form an intermediate frequency (IF) signal. The IF signal undergoes low-frequency filtering and amplification in the IF processing circuit to match the input range of the analog-to-digital converter (ADC). Finally, it is digitized by the ADC and enters the integrated processing module. The integrated processing module processes the data and ultimately calculates the wind speed and direction information.

10. The measurement method of the microwave photonics wind radar according to claim 9, wherein, The power divider is a power divider that uses a microstrip current structure.

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