Gain matching control method and device for radio frequency signal

Abstract

The invention provides a gain matching control method and device for a radio frequency signal, and relates to the technical field of radio direction finding, and the method comprises the steps: carrying out the radio frequency amplification of a weak radio frequency microwave signal, and obtaining a radio frequency amplification signal; performing weak signal amplification and noise reduction processing on the radio frequency amplification signal to obtain a noise reduction signal; performing wavelength division multiplexing on the multi-channel noise reduction signal to obtain a wavelength division multiplexing signal; performing shunt conversion on the wavelength division multiplexing signal to obtain a shunt signal; and performing gain matching control on the shunt signals to obtain corresponding radio frequency signals, and completing gain matching control on the radio frequency signals. The problems of low accuracy, reliability and effectiveness of aerial direction finding are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of radio direction finding, and in particular to a method and device for controlling gain matching of radio frequency signals. Background Art

[0002] In the field of target situation system, the hardware system tethered floating wing platform is used as the carrier platform. Its main task is to carry the monitoring and direction finding antenna array and stay in the air for a long time to perform monitoring and direction finding work. For aerial monitoring and direction finding operations, multiple target requirements need to be achieved: in terms of direction finding sensitivity, the typical value of ≤10uV / m (corresponding to 25kHz bandwidth) must be achieved; the maximum direction finding intermediate frequency bandwidth should reach 80MHz; the maximum lift-off altitude shall not be less than 100 meters; the maximum lift-off duration shall be ≥10 hours.

[0003] At present, most existing direction-finding equipment is built in the form of fixed stations. However, the height of fixed stations and antenna heights are subject to many restrictions, which directly leads to relatively small monitoring distances and monitoring areas. In addition, whether it is mobile or fixed radio monitoring and direction-finding equipment installed on the ground, it is difficult to avoid the adverse effects of terrain. Landforms such as tall buildings and hills will significantly interfere with the final results of monitoring and direction-finding, especially the signal shielding effect is extremely prominent. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, a gain matching control method and device for radio frequency signals provided by the present invention solve the problems of low accuracy, reliability and effectiveness of aerial direction finding.

[0005] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is: a gain matching control method of a radio frequency signal, comprising: Performing radio frequency amplification on the weak radio frequency microwave signal to obtain a radio frequency amplified signal; Performing weak signal amplification and noise reduction processing on the radio frequency amplified signal to obtain a noise reduction signal; Performing wavelength division multiplexing on the multi-channel noise reduction signals to obtain wavelength division multiplexed signals; Performing branch conversion on the wavelength division multiplexing signal to obtain a branch signal; Gain matching control is performed on the branch signal to obtain a corresponding radio frequency signal, thereby completing gain matching control of the radio frequency signal.

[0006] A gain matching control device for radio frequency signals, comprising: an antenna radio frequency input port, an antenna end optical splitter, a tethered cable, an optical splitter and a radio frequency output port connected in series in sequence; wherein the antenna radio frequency input port and the radio frequency output port both comprise a radio frequency amplification compensation network and a feeding network connected in series in sequence, and the radio frequency amplification compensation network comprises a low noise amplifier.

[0007] Furthermore, the RF amplification compensation network includes: a resistor R1, a capacitor C3, a capacitor C2, a capacitor C1 and a low-noise amplifier U1; wherein one end of the capacitor C3 serves as an input end of the RF amplification compensation network, the other end of the capacitor C3 is respectively connected to a first pin of the low-noise amplifier U1 and one end of the capacitor C1, the other end of the capacitor C1 is connected to one end of the resistor R1, the second pin and the fourth pin of the low-noise amplifier U1 are grounded, the third pin of the low-noise amplifier U1, the other end of the resistor R1 and one end of the capacitor C2 are all connected to the feeding network, and the other end of the capacitor C2 serves as an output end of the RF amplification compensation network.

[0008] Furthermore, the feeding network includes: a grounding capacitor C4, a polarized grounding capacitor C5, a chip U2, a polarized grounding capacitor C6, a grounding capacitor C7, an inductor L1 and an inductor L2; wherein, one end of the inductor L1 is connected to the third pin of the low-noise amplifier U1, the other end of the resistor R1 and one end of the capacitor C2, the other end of the inductor L1 is respectively connected to the grounding capacitor C4, the positive electrode of the polarized grounding capacitor C5 and the third pin of the chip U2, the second pin of the chip U2 is grounded, the first pin of the chip U2 is respectively connected to the grounding capacitor C7, the positive electrode of the polarized grounding capacitor C6 and one end of the inductor L2, and the other end of the inductor L2 is a voltage input terminal.

[0009] The beneficial effects of the present invention are as follows: (1) It can effectively compensate for the gain loss of the signal during the long-distance transmission process at high altitude, greatly improve the stability and accuracy of the entire direction-finding information transmission system, and provide more reliable and efficient technical support for applications in related fields. (2) By setting low-noise amplifiers at the antenna end and the ground terminal for gain compensation, the gain loss of the signal in different conversion and transmission links can be compensated. The weak RF signal received by the antenna port is gain compensated after the gain conversion loss, and then gain compensation is performed again after conversion. This cycle is repeated, and finally the ground terminal can restore the original RF microwave signal received by the receiving antenna end, ensuring the effectiveness and accuracy of the entire signal transmission system. (3) The low-noise amplifier is connected to the antenna end front end and the ground terminal optical-to-RF output port, which effectively amplifies the weak signal and improves the signal strength, so that it can remain relatively stable in a complex transmission environment. At the same time, the low-noise amplifier reduces noise interference and improves the signal-to-noise ratio of the signal, thereby improving the signal quality, so that the receiving end can restore the original signal more accurately. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] This specification will be further described in the form of exemplary embodiments, which will be described in detail by the accompanying drawings. These embodiments are not restrictive, and in these embodiments, the same number represents the same structure, wherein: Figure 1 is an exemplary flow chart of a gain matching control method for a radio frequency signal according to some embodiments of this specification; Figure 2 is an exemplary schematic diagram of a gain matching control device for a radio frequency signal according to some embodiments of this specification; Figure 3 is an exemplary schematic diagram of a radio frequency amplification compensation network and a feeding network according to some embodiments of this specification. DETAILED DESCRIPTION

[0011] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0012] Embodiment 1 Figure 1 FIG. 1 is an exemplary flow chart of a gain matching control method for a radio frequency signal according to some embodiments of this specification. Figure 1 As shown, the process includes the following steps.

[0013] S1: Perform radio frequency amplification on the weak radio frequency microwave signal to obtain a radio frequency amplified signal.

[0014] The weak radio frequency microwave signal is a microwave signal obtained by the radio frequency input port of the antenna.

[0015] The RF amplified signal is a microwave signal after compensating for the gain loss introduced by the RF optical conversion module at the antenna end.

[0016] In some embodiments, the processor may perform radio frequency amplification on the weak radio frequency microwave signal introduced by the antenna end, compensate for the gain loss introduced by the radio frequency optical conversion module at the antenna end, and obtain a radio frequency amplified signal.

[0017] S2: Perform weak signal amplification and noise reduction processing on the radio frequency amplified signal to obtain a noise reduction signal.

[0018] The noise reduction signal is a signal that compensates for the loss of RF-to-optical gain.

[0019] In some embodiments, the processor may utilize a low noise amplifier to amplify a weak signal, reduce noise based on a total noise factor, compensate for the gain loss of RF-to-light conversion, and obtain a noise-reduced signal.

[0020] In some embodiments, the total noise coefficient of the RF amplified signal is expressed as: ; in, represents the total noise figure, represents the noise figure of the first-stage amplifier, represents the noise figure of the second-stage amplifier, represents the noise figure of the third-stage amplifier, represents the noise figure of the fourth-stage amplifier, represents the noise figure of the nth stage amplifier, represents the first stage amplifier gain, represents the second stage amplifier gain, represents the third stage amplifier gain, Represents the gain of the n-1th stage amplifier.

[0021] S3: performing wavelength division multiplexing on the multi-channel noise reduction signals to obtain wavelength division multiplexed signals.

[0022] The wavelength division multiplexing signal is a signal that integrates microwave signals of different frequencies and performs frequency division based on the different frequencies of the microwaves.

[0023] In some embodiments, the processor may transmit the multi-channel noise reduction signal to the antenna end optical splitter to obtain a wavelength division multiplexed signal.

[0024] S4: performing branch conversion on the wavelength division multiplexing signal to obtain a branch signal.

[0025] The branched signal is a signal obtained by branching the optical signal based on the microwave frequency.

[0026] In some embodiments, the processor may utilize an optical splitter to perform branch conversion on the wavelength division multiplexing signal to obtain a multi-branch signal.

[0027] S5: Perform gain matching control on the branch signal to obtain a corresponding radio frequency signal, thereby completing gain matching control on the radio frequency signal.

[0028] The RF signal is a RF output signal after gain matching.

[0029] In some embodiments, the processor can access the low noise amplifier matching control at the output port of the optical-to-RF converter, and after converting the branched signal into an RF signal, the signal strength is enhanced again to compensate for the gain loss accumulated during the conversion of the optical splitter at the ground terminal and the transmission of the high-voltage tethered cable, and obtain the RF signal. For example, if a loss of 10 dB is detected during the conversion of the optical splitter at the ground terminal and the transmission of the high-voltage tethered cable, the processor can perform gain matching through the gain matching control device at the output port of the optical-to-RF converter to compensate for the loss of 10 dB, achieve balance, and obtain the RF signal.

[0030] In this way, (1) the gain loss of the signal during long-distance transmission at high altitude can be effectively compensated, greatly improving the stability and accuracy of the entire direction-finding information transmission system, and providing more reliable and efficient technical support for applications in related fields. (2) By setting up low-noise amplifiers at the antenna end and the ground terminal for gain compensation, the gain loss of the signal in different conversion and transmission links can be compensated. The weak RF signal received by the antenna port is gain compensated after gain conversion loss, and then gain compensated again after conversion. This cycle allows the ground terminal to restore the original RF microwave signal received by the receiving antenna end, ensuring the effectiveness and accuracy of the entire signal transmission system. (3) The low-noise amplifier is connected to the antenna end front end and the ground terminal optical-to-RF output port, which effectively amplifies the weak signal and improves the signal strength, so that it can remain relatively stable in a complex transmission environment. At the same time, the low-noise amplifier reduces noise interference and improves the signal-to-noise ratio, thereby improving the signal quality, so that the receiving end can restore the original signal more accurately.

[0031] Embodiment 2 Figure 2 FIG. 1 is an exemplary schematic diagram of a gain matching control device for a radio frequency signal according to some embodiments of this specification. Figure 2 As shown, a gain matching control device for radio frequency signals includes an antenna radio frequency input port, an antenna end optical splitter, a tethered cable, an optical splitter and a radio frequency output port connected in series in sequence; wherein the antenna radio frequency input port and the radio frequency output port both include a radio frequency amplification compensation network and a feeding network connected in series in sequence, and the radio frequency amplification compensation network includes a low noise amplifier.

[0032] In some embodiments, Figure 3 As shown, the RF amplification compensation network includes: a resistor R1, a capacitor C3, a capacitor C2, a capacitor C1 and a low noise amplifier U1; wherein, one end of the capacitor C3 serves as the input end of the RF amplification compensation network, the other end of the capacitor C3 is respectively connected to the first pin of the low noise amplifier U1 and one end of the capacitor C1, the other end of the capacitor C1 is connected to one end of the resistor R1, the second pin and the fourth pin of the low noise amplifier U1 are grounded, the third pin of the low noise amplifier U1, the other end of the resistor R1 and one end of the capacitor C2 are all connected to the feeding network, and the other end of the capacitor C2 serves as the output end of the RF amplification compensation network.

[0033] In some embodiments, the RF amplification compensation network in the RF output port includes: a resistor R21, a capacitor C21, a capacitor C22, a capacitor C24 and a low noise amplifier U21; wherein, one end of the capacitor C21 serves as the input end of the RF amplification compensation network in the RF output port, the other end of the capacitor C21 is respectively connected to the first pin of the low noise amplifier U21 and one end of the capacitor C24, the other end of the capacitor C24 is connected to one end of the resistor R21, the second pin and the fourth pin of the low noise amplifier U21 are grounded, the third pin of the low noise amplifier U21, the other end of the resistor R21 and one end of the capacitor C22 are all connected to the feeding network, and the other end of the capacitor C22 serves as the output end of the RF amplification compensation network in the RF output port.

[0034] In some embodiments, the input end of the RF amplification and compensation network in the antenna RF input port is connected to the antenna receiving port, and the output end of the RF amplification and compensation network in the antenna RF input port is connected to the antenna end optical splitter; the input end of the RF amplification and compensation network in the RF output port is connected to the optical splitter, and the output end of the RF amplification and compensation network in the RF output port serves as the output port of the gain matching control device of the RF signal. The specific connection relationship of the gain matching control device of the RF signal is shown in Table 1.

[0035] Table 1 Specific connection relationship of the gain matching control device of the radio frequency signal

[0036] In some embodiments, Figure 3 As shown, the feeding network includes: a grounding capacitor C4, a polarized grounding capacitor C5, a chip U2, a polarized grounding capacitor C6, a grounding capacitor C7, an inductor L1 and an inductor L2; wherein, one end of the inductor L1 is connected to the third pin of the low noise amplifier U1, the other end of the resistor R1 and one end of the capacitor C2, the other end of the inductor L1 is respectively connected to the grounding capacitor C4, the positive electrode of the polarized grounding capacitor C5 and the third pin of the chip U2, the second pin of the chip U2 is grounded, the first pin of the chip U2 is respectively connected to the grounding capacitor C7, the positive electrode of the polarized grounding capacitor C6 and one end of the inductor L2, and the other end of the inductor L2 is a voltage input terminal.

[0037] In some embodiments, the models of the low noise amplifier U1 and the low noise amplifier U21 may be BR9513, and the models of the chip U2 and the chip U22 may be 7805 chips.

[0038] In some embodiments, the feeding network in the RF output port includes: a grounded capacitor C23, a polarized grounded capacitor C25, a chip U22, a polarized grounded capacitor C26, a grounded capacitor C27, an inductor L21 and an inductor L22; wherein, one end of the inductor L21 is connected to the third pin of the low noise amplifier U21, the other end of the resistor R21 and one end of the capacitor C22, the other end of the inductor L21 is respectively connected to the grounded capacitor C23, the positive electrode of the polarized grounded capacitor C25 and the third pin of the chip U22, the second pin of the chip U22 is grounded, the first pin of the chip U22 is respectively connected to the grounded capacitor C27, the positive electrode of the polarized grounded capacitor C26 and one end of the inductor L22, and the other end of the inductor L22 is the voltage input terminal in the RF output port.

[0039] In some embodiments, by placing a low noise amplifier in front, weak signals can be amplified and noise can be reduced, compensating for the gain loss introduced by RF conversion, optical splitters and tethered cables.

[0040] In some embodiments, the RF amplification compensation network in the RF input port of the antenna is used to receive the signal of the antenna receiving port, the capacitor C3 is used to receive the weak signal, the low noise amplifier U1 is used to amplify and reduce the noise of the received weak signal, the inductor L2 of the feeding network is used to receive the input voltage, and the signal is impedance matched to obtain the noise reduction signal, which is output to the antenna end optical splitter through the capacitor C2; the multi-channel noise reduction signal is wavelength division multiplexed through the antenna end optical splitter to obtain a wavelength division multiplexed signal; the wavelength division multiplexed signal converted by the antenna end is transmitted to the optical splitter through a high-voltage tethered cable and then output to the RF output port, the RF amplification compensation network in the RF output port is used to receive the RF weak signal received by the antenna port, the capacitor C21 is used to receive the signal, the low noise amplifier U21 is used to amplify and reduce the noise of the received signal, and gain compensation is performed again after gain conversion loss, and the feeding network in the RF output port is used to perform impedance matching, and the obtained RF signal is output to the ground terminal through the capacitor C22, and the ground terminal restores the original RF microwave signal received by the receiving antenna end to obtain the final output RF signal.

[0041] In some embodiments, the RF microwave signal technical requirements may include: 1) Operating frequency: 20MHz~3GHz; 2) Gain: ≤-28dB; 3) Input power upper limit: ≤20dBm; 4) Input P-1dB: ≥17dBm; 5) Input and output standing wave: ≤2.0; 6) Frequency deviation: ≤0.1ppm; 7) Noise coefficient: ≤36dB; 8) Amplitude stability: ≤±0.5dB (comparison at the same frequency point); 9) Phase stability: ≤±3° (compared at the same frequency point, tested at intervals of 1 hour under the same temperature conditions); 10) Amplitude consistency between channels: ≤±1dB (comparison at the same frequency point); 11) Phase consistency between channels: ≤±20° (compared at the same frequency point, the specific phase difference of each channel is marked at the factory); 12) Inter-channel isolation: ≥40dB; 13) RF port: SMA; 14) Fiber optic interface: FC / APC; The optical terminal components are divided into antenna terminals and ground terminals, both of which have the same physical interface and definition. The bayonet position on the optical fiber connector corresponds to the connector when connecting the optical fiber, and the optical fiber is placed naturally when in use.

Claims

1. A gain matching control method for a radio frequency signal, characterized in that: include: Performing radio frequency amplification on the weak radio frequency microwave signal to obtain a radio frequency amplified signal; Performing weak signal amplification and noise reduction processing on the radio frequency amplified signal to obtain a noise reduction signal; Performing wavelength division multiplexing on the multiple noise reduction signals to obtain wavelength division multiplexed signals; Performing branch conversion on the wavelength division multiplexing signal to obtain a branch signal; The branch signal is subjected to gain matching control to obtain a corresponding radio frequency signal, thereby completing gain matching control of the radio frequency signal.

2. A gain matching control device for a radio frequency signal, used to execute the gain matching control method according to claim 1, characterized in that: include: An antenna RF input port, an antenna end optical splitter, a tethered cable, an optical splitter and an RF output port are sequentially connected in series; wherein the antenna RF input port and the RF output port both comprise an RF amplification compensation network and a feeding network which are sequentially connected in series, and the RF amplification compensation network comprises a low noise amplifier.

3. The gain matching control device for radio frequency signals according to claim 2, characterized in that: The radio frequency amplification compensation network includes: a resistor R1, a capacitor C3, a capacitor C2, a capacitor C1 and a low noise amplifier U1; wherein one end of the capacitor C3 serves as the input end of the radio frequency amplification compensation network, the other end of the capacitor C3 is respectively connected to the first pin of the low noise amplifier U1 and one end of the capacitor C1, the other end of the capacitor C1 is connected to one end of the resistor R1, the second pin and the fourth pin of the low noise amplifier U1 are grounded, the third pin of the low noise amplifier U1, the other end of the resistor R1 and one end of the capacitor C2 are all connected to the feeding network, and the other end of the capacitor C2 serves as the output end of the radio frequency amplification compensation network.

4. The gain matching control device for radio frequency signals according to claim 3, characterized in that: The feeding network includes: a grounding capacitor C4, a polarized grounding capacitor C5, a chip U2, a polarized grounding capacitor C6, a grounding capacitor C7, an inductor L1 and an inductor L2; wherein, one end of the inductor L1 is connected to the third pin of the low-noise amplifier U1, the other end of the resistor R1 and one end of the capacitor C2, the other end of the inductor L1 is respectively connected to the grounding capacitor C4, the positive electrode of the polarized grounding capacitor C5 and the third pin of the chip U2, the second pin of the chip U2 is grounded, the first pin of the chip U2 is respectively connected to the grounding capacitor C7, the positive electrode of the polarized grounding capacitor C6 and one end of the inductor L2, and the other end of the inductor L2 is a voltage input terminal.

Images