Radio frequency feedback circuit for unmanned aerial vehicle communication

Abstract

The utility model relates to the technical field of radio frequency feedback, and discloses a radio frequency feedback circuit for unmanned aerial vehicle communication, which is characterized in that a low-noise amplification module preliminarily amplifies signals received by an antenna to reduce introduction of noise; the automatic gain control module automatically adjusts the gain of the amplifier according to the strength of the received signal so as to maintain the stability of the output signal and further optimize the signal quality; the frequency mixing module mixes the received radio frequency signal with a signal generated by the local oscillator and converts the signal frequency into an intermediate frequency or a baseband, the intermediate frequency amplification module amplifies the mixed intermediate frequency signal so as to facilitate subsequent signal processing, and the detection module extracts an original information signal from the modulated radio frequency signal and sends the original information signal to the local oscillator. Original data or audio frequency and the like are recovered, and the signal demodulation process is completed; and the phase-locked loop module compares the phase difference between the input signal and the output signal and adjusts the parameters of the voltage-controlled oscillator, so that the phase synchronization of the input signal and the output signal is realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to radio frequency feedback technical field, concretely is a kind of radio frequency feedback circuit of unmanned plane communication. BACKGROUND

[0002] Radio frequency feedback circuit refers to the radio frequency signal at output end is fed back to input end by certain mode in radio frequency communication system, to realize the adjustment or control of input signal to a kind of circuit.Feedback mechanism helps to improve the stability of communication system, improve signal quality and enhance the anti-interference ability of system.

[0003] Current radio frequency feedback based on unmanned plane communication is not convenient for amplifying, noise reduction processing to the signal received, reduces the stability of signal output, lead to low signal quality, and current unmanned plane communication signal, there is phase difference between input signal and output signal, reduce the accuracy and stability of communication, therefore we need to propose a kind of radio frequency feedback circuit of unmanned plane communication. UTILITY MODEL CONTENT

[0004] The utility model aims at providing a kind of radio frequency feedback circuit of unmanned plane communication, low noise amplifier module carries out the primary amplification to the signal received by antenna, while minimizing the introduction of noise, to improve the sensitivity of signal reception;Automatic gain control module adjusts the gain of amplifier according to the strength of received signal, to maintain the stability of output signal, further optimize signal quality;Mixing module mixes the received radio frequency signal with the signal generated by local oscillator, changes signal frequency to intermediate frequency or baseband, intermediate frequency amplification module amplifies the intermediate frequency signal after mixing, to carry out subsequent signal processing, detection module extracts original information signal from modulated radio frequency signal, restores into original data or audio etc., completes the demodulation process of signal;Phase-locked loop module compares the phase difference between input signal and output signal, and adjusts the parameter of voltage-controlled oscillator, realizes the phase synchronization of input signal and output signal, to solve the problem raised in the above background technique.

[0005] To achieve the above object, the utility model provides the following technical scheme: a kind of radio frequency feedback circuit of unmanned plane communication, comprising: for receiving signal radio frequency receiving unit, for processing signal radio frequency signal processing unit, for feedback signal feedback control unit;

[0006] The radio frequency receiving unit includes:

[0007] As receiving device and capturing aerial radio frequency signal antenna;

[0008] Low noise amplifier module amplifies the signal received by antenna;

[0009] Filtering module for filtering out useless frequency band in amplified signal;

[0010] The radio frequency signal processing unit comprises:

[0011] a mixing module for mixing the filtered signal with a local oscillator signal and generating an intermediate frequency signal;

[0012] an intermediate frequency amplification module for amplifying the intermediate frequency signal;

[0013] a detection module for demodulating the signal output by the intermediate frequency amplification module;

[0014] The feedback control unit comprises:

[0015] an automatic gain control module for monitoring the received signal strength;

[0016] a phase-locked loop module connected with the local oscillator and correcting and locking the frequency of the local oscillator;

[0017] The antenna, the low-noise amplification module, the filtering module, the mixing module, the intermediate frequency amplification module, and the detection module are connected in sequence, and the automatic gain control module is electrically connected with the low-noise amplification module and the intermediate frequency amplification module respectively.

[0018] Preferably, the low-noise amplification module comprises an amplifier U2, the 2-pin of the amplifier U2 is connected with a resistor R301, a resistor R201, and a capacitor C201 in sequence, and the capacitor C201 is connected to the output end of the antenna, the capacitor C101 is connected between the 1-pin and the 2-pin of the amplifier U2, the resistor R101 is connected between the 1-pin of the amplifier U2 and the wiring ends of the resistor R301 and the resistor R201, and the capacitor C401 is connected to the 1-pin of the amplifier U2.

[0019] Preferably, the mixing module comprises a chip U1, a wiring seat P3, a wiring seat P4, and a wiring seat P5, the 1-pin of the chip U1 is connected with a capacitor C1, a capacitor C2, and a capacitor C3 respectively, the 6-pin of the chip U1 is connected with a capacitor C4 and a capacitor C5, and the wiring ends of the capacitor C4 and the capacitor C5 are connected with a grounded inductor L1, the 10-pin and the 11-pin of the chip U1 are connected with a capacitor C8, a capacitor C9, and a resistor R1, the wiring ends of the capacitor C9 and the resistor R1 are connected to the wiring seat P4, and the 16-pin of the chip U1 is connected with a resistor R6 and a capacitor C11 and the wiring seat P5.

[0020] Preferably, the intermediate frequency amplification module comprises an amplifier IC1, a terminal block J10, a terminal block J20, a resistor R21 and a resistor R61 are connected between the 1st pin and the 2nd pin of the amplifier IC1, the resistor R21 is connected in parallel on the terminal block J10, a resistor R31 and a resistor R71 are connected between the 6th pin and the 7th pin of the amplifier IC1, the resistor R31 is connected in parallel with a resistor R41 and a resistor R51 connected in series, and the resistor R15 is connected in parallel on the terminal block J20.

[0021] Preferably, the detection module comprises a terminal block PM, a terminal block POW, a triode Q2 and a diode D1, the 2nd pin of the terminal block PM is connected with the 1st pin and the 2nd pin of the terminal block POW, an inductor L20 is connected between the collector of the triode Q2 and the 1st pin of the terminal block PM, a capacitor C112 is connected between the collector of the triode Q2 and the 2nd pin of the diode D1, a resistor R22 is connected between the base of the triode Q2 and the 3rd pin of the diode D1, a resistor R12 is connected between the base of the triode Q2 and the 1st pin of the diode D1, and a capacitor C12, a resistor R32, an inductor L10 and a capacitor C102 connected in parallel are sequentially connected on the base of the triode Q2.

[0022] Preferably, the automatic gain control module comprises a chip U8 and an amplifier U18, the 3rd pin of the amplifier U18 is connected to the 13th pin of the chip U8, the 4th pin of the amplifier U18 is connected to the 3rd pin of the chip U8, the 1st pin of the chip U8 is connected with a resistor R360, the 5th pin of the chip U8 is connected with a resistor R380, the 2nd pin of the chip U8 is connected with a resistor R390, the 4th pin of the chip U8 is connected with a resistor R410, and the resistor R360, the resistor R380, the resistor R390 and the resistor R410 are all connected to the 1st pin of the amplifier U18.

[0023] Preferably, the phase-locked loop module comprises an amplifier IC6, an amplifier IC7 and an amplifier IC8, a resistor R207 and a resistor R217 are connected to the 7th pin of the amplifier IC6, the 3rd pin of the amplifier IC8 is connected between the resistor R207 and the resistor R217, and a resistor R247 is connected between the 1st pin of the amplifier IC7 and the 2nd pin of the amplifier IC8.

[0024] Compared with the prior art, the utility model has the advantages of:

[0025] 1、 the utility model discloses a low noise amplification module to the signal received by antenna is amplified primarily, and the introduction of noise is reduced as far as possible to improve the sensitivity of signal reception, the automatic gain control module is adjusted according to the strength of received signal automatically the gain of amplifier, to keep the stability of output signal, further optimize signal quality;

[0026] 2, The utility model discloses a mixing frequency module mixes the signal frequency of received radio frequency signal and the signal of local oscillator, and the signal frequency is transformed to intermediate frequency or baseband, and the intermediate frequency amplification module amplifies the intermediate frequency signal after mixing, so that subsequent signal processing is carried out, and the detection module extracts the original information signal from the modulated radio frequency signal, restores into original data or audio etc., and completes the demodulation process of signal.

[0027] 3, The utility model discloses a phase-locked loop module compares the phase difference between input signal and output signal, and adjusts the parameter of voltage-controlled local oscillator, realizes the phase synchronization of input signal and output signal.

[0028] 4, The utility model discloses the performance and cooperative work mode of each module are optimized, and the overall performance of unmanned plane communication system can be improved, including improving communication rate, reducing error rate, enhancing anti-interference ability. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is system block diagram of the utility model;

[0030] Figure 2 It is circuit diagram of low noise amplifier module of the utility model;

[0031] Figure 3 It is circuit diagram of mixing frequency module of the utility model;

[0032] Figure 4 It is circuit diagram of intermediate frequency amplifier module of the utility model;

[0033] Figure 5 It is circuit diagram of detection module of the utility model;

[0034] Figure 6 It is circuit diagram of automatic gain control module of the utility model;

[0035] Figure 7 It is circuit diagram of phase-locked loop module of the utility model. DETAILED DESCRIPTION

[0036] The technical scheme in the embodiments of the utility model will be described clearly and completely below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the utility model.

[0037] Please refer to Figures 1-7The utility model provides a technical scheme: a radio frequency feedback circuit of unmanned plane communication, include: radio frequency receiving unit for receiving signal, radio frequency signal processing unit for processing signal, feedback control unit for feeding back signal,

[0038] The radio frequency receiving unit includes:

[0039] The antenna is received by the receiving device and captures the radio frequency signal in the air;

[0040] The low noise amplification module is amplified to the signal received by the antenna;

[0041] The low noise amplification module includes amplifier U2, resistance R301, resistance R201, capacitor C201 are connected in sequence on the 2 feet of the amplifier U2, and the capacitor C201 is connected on the output end of the antenna, the capacitor C101 is connected between the 1 foot and the 2 feet of the amplifier U2, the resistance R101 is connected between the 1 foot of the amplifier U2 and the wiring end of resistance R301, resistance R201, and the capacitor C401 is connected on the 1 foot of the amplifier U2.

[0042] Resistance R201, capacitor C201 constitute input filter circuit, are used for smoothing input voltage, resistance R301 and capacitor C301 are voltage step-down circuit, and input voltage is reduced to 12V, capacitor C101, capacitor C401 are filter capacitance, are used for filtering output voltage, resistance R501 and capacitor C601 are voltage dividing circuit of output voltage, are used for feeding back to the input end of operational amplifier, and capacitor C501 is bypass capacitor, is used for inhibiting high frequency interference.

[0043] The filter module is used to filter out the useless frequency band in the amplified signal;

[0044] The radio frequency signal processing unit includes:

[0045] The mixing module is used for mixing the filtered signal with the local oscillator signal and generating the intermediate frequency signal;

[0046] The mixing module includes chip U1, wiring seat P3, wiring seat P4, wiring seat P5, the 1 foot of the chip U1 is connected with capacitor C1, capacitor C2, capacitor C3 respectively, the 6 foot of the chip U1 is connected with capacitor C4, capacitor C5 between wiring seat P3, and the wiring end of capacitor C4, capacitor C5 is connected with the inductance L1 of ground, the 10 foot and 11 foot of the chip U1 are connected with capacitor C8, capacitor C9, resistance R1, and the wiring end of capacitor C9, resistance R1 is connected on wiring seat P4;The 16 foot of the chip U1 is connected with resistance R6, capacitor C11 between wiring seat P5.

[0047] The terminal J1 is connected to the antenna, the capacitors C1, C2, C3, C4 are filter capacitors, the inductor L12 is a filter inductor, the chip U1 is a radio frequency transceiver chip for signal transmission and reception, the capacitors C5, C6, C7, C8 and C9 are capacitors for matching and filtering, the resistors R1, R2, R3, R4 and R5 constitute a bias circuit, the terminal P3 is a terminal for power input, and the terminal P5 is a terminal for antenna output.

[0048] An intermediate frequency amplification module for amplifying and processing the intermediate frequency signal;

[0049] The intermediate frequency amplification module comprises an amplifier IC1, a terminal J10 and a terminal J20, a resistor R21 and a resistor R61 are connected between the 1st pin and the 2nd pin of the amplifier IC1, the resistor R21 is connected in parallel to the terminal J10, a resistor R31 and a resistor R71 are connected between the 6th pin and the 7th pin of the amplifier IC1, the resistor R31 has a resistor R41 and a resistor R51 connected in series in parallel across the two ends of the resistor R31, and the resistor R15 is connected in parallel to the terminal J20.

[0050] The resistor R21 and the resistor R61 are input end voltage dividing resistors for adjusting the input signal level, the crystal oscillator X1 is a frequency source of the intermediate frequency amplification module, the capacitor C11 is a filter capacitor, the resistor R11 is a resistor for limiting current, the resistor R71 and the capacitor C21 constitute an RC network of the intermediate frequency amplification module, and the resistor R31 and the resistor R51 constitute output end voltage dividing resistors.

[0051] A detection module for adjusting the signal output by the intermediate frequency amplification module;

[0052] The detection module comprises a terminal PM, a terminal POW, a triode Q2 and a diode D1, the triode Q2 is a Darlington triode, the 2nd pin of the terminal PM is connected to the 1st pin and the 2nd pin of the terminal POW, an inductor L20 is connected between the collector of the triode Q2 and the 1st pin of the terminal PM, a capacitor C112 is connected between the collector of the triode Q2 and the 2nd pin of the diode D1, a resistor R22 is connected between the base of the triode Q2 and the 3rd pin of the diode D1, a resistor R12 is connected between the base of the triode Q2 and the 1st pin of the diode D1, and a capacitor C12, a resistor R32, an inductor L10 and a capacitor C102 connected in parallel are sequentially connected to the base of the triode Q2.

[0053] The inductor L10 and the capacitor C102 are input filter circuits for smoothing the input voltage, the resistor R32 and the capacitor C12 constitute a voltage step-down circuit for reducing the input voltage to a suitable level, the transistor Q2 serves as a voltage regulator, and the capacitor C100 is a large-capacity filter capacitor for stabilizing the output voltage.

[0054] The feedback control unit comprises:

[0055] The automatic gain control module for monitoring the received signal strength comprises:

[0056] The automatic gain control module comprises a chip U8, an amplifier U18, the pin 3 of the amplifier U18 is connected to the pin 13 of the chip U8, the pin 4 of the amplifier U18 is connected to the pin 3 of the chip U8, the pin 1 of the chip U8 is connected to a resistor R360, the pin 5 of the chip U8 is connected to a resistor R380, the pin 2 of the chip U8 is connected to a resistor R390, the pin 4 of the chip U8 is connected to a resistor R410, and the resistors R360, R380, R390 and R410 are all connected to the pin 1 of the amplifier U18.

[0057] The resistors R260, R280 and R310 constitute a voltage dividing circuit for the input signal, the amplifier U18 performs voltage amplification, the capacitors C230 and C104 are filter capacitors for filtering the output signal, the resistors R50 and R52 are bias resistors for the input signal, and the capacitors C280 and C300 constitute a coupling circuit for the output signal.

[0058] The phase-locked loop module is connected to the local oscillator and corrects and locks the frequency of the local oscillator;

[0059] The phase-locked loop module comprises an amplifier IC6, an amplifier IC7 and an amplifier IC8, the pin 7 of the amplifier IC6 is connected to a resistor R207 and a resistor R217, the pin 3 of the amplifier IC8 is connected between the resistors R207 and R217, and the pin 1 of the amplifier IC7 is connected to the pin 2 of the amplifier IC8 via a resistor R247.

[0060] The capacitors C177 and C187 are filter capacitors for filtering the input signal, the resistors R227 and R257 are 1M resistors serving as bias resistors, the resistors R217 and R247 are 2K resistors serving as voltage dividing resistors, the resistors R207 and R267 are 10K resistors serving as voltage dividing resistors, the amplifiers IC6 and IC7 are TL084 operational amplifiers for amplifying and processing the input signal, and the amplifier IC8 is a TL084 operational amplifier for output voltage adjustment.

[0061] The antenna, low-noise amplification module, filtering module, mixing module, intermediate frequency amplification module and detection module are connected in sequence, and the automatic gain control module is electrically connected with the low-noise amplification module and the intermediate frequency amplification module respectively.

[0062] Although the embodiments of the present application have been shown and described, it should be understood by those ordinary skilled in the art that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A radio frequency feedback circuit for unmanned aerial vehicle (UAV) communication, characterized in that, include: Radio frequency receiving unit for receiving signals, radio frequency signal processing unit for processing signals, and feedback control unit for feeding back signals; The radio frequency receiving unit includes: As a receiving device, it is an antenna that captures radio frequency signals in the air; A low-noise amplifier module that amplifies the signal received by the antenna; A filtering module used to remove unwanted frequency bands from amplified signals; The radio frequency signal processing unit includes: A mixing module used to mix the filtered signal with the local oscillator signal to generate an intermediate frequency signal; An intermediate frequency (IF) amplifier module for amplifying IF signals; A detector module that modulates the signal output from the intermediate frequency amplifier module; The feedback control unit includes: Automatic gain control module used to monitor the strength of received signals; A phase-locked loop module that connects to a local oscillator and corrects and locks the frequency of the local oscillator; The antenna, low-noise amplifier module, filter module, mixer module, intermediate frequency amplifier module, and detector module are connected in sequence, and the automatic gain control module is electrically connected to the low-noise amplifier module and the intermediate frequency amplifier module respectively.

2. The radio frequency feedback circuit for UAV communication according to claim 1, characterized in that: The low-noise amplification module includes an amplifier U2. Resistors R301, R201, and C201 are connected sequentially to pin 2 of the amplifier U2. The capacitor C201 is connected to the output terminal of the antenna. A capacitor C101 is connected between pin 1 and pin 2 of the amplifier U2. A resistor R101 is connected between pin 1 of the amplifier U2 and the terminals of resistors R301 and R201. A capacitor C401 is connected to pin 1 of the amplifier U2.

3. The radio frequency feedback circuit for UAV communication according to claim 1, characterized in that: The mixing module includes a chip U1, a terminal block P3, a terminal block P4, and a terminal block P5. Capacitors C1, C2, and C3 are connected to pin 1 of the chip U1. Capacitors C4 and C5 are connected between pin 6 of the chip U1 and terminal block P3, and the terminals of capacitors C4 and C5 are connected to a grounded inductor L1. Capacitors C8 and C9, and a resistor R1 are connected between pins 10 and 11 of the chip U1, and the terminals of capacitors C9 and R1 are connected to terminal block P4. A resistor R6 and a capacitor C11 are connected between pin 16 of the chip U1 and terminal block P5.

4. The radio frequency feedback circuit for UAV communication according to claim 1, characterized in that: The intermediate frequency amplification module includes amplifier IC1, terminal block J10, and terminal block J20. Resistors R21 and R61 are connected between pins 1 and 2 of amplifier IC1. Resistor R21 is connected in parallel to terminal block J10. Resistors R31 and R71 are connected between pins 6 and 7 of amplifier IC1. Resistors R41 and R51 are connected in series in parallel across the two ends of resistor R31. Resistor R15 is connected in parallel to terminal block J20.

5. The radio frequency feedback circuit for UAV communication according to claim 1, characterized in that: The detection module includes a connector PM, a connector POW, a transistor Q2, and a diode D1. Pin 2 of the connector PM is connected to pins 1 and 2 of the connector POW. An inductor L20 is connected between the collector of the transistor Q2 and pin 1 of the connector PM. A capacitor C112 is connected between the collector of the transistor Q2 and pin 2 of the diode D1. A resistor R22 is connected between the base of the transistor Q2 and pin 3 of the diode D1. A resistor R12 is connected between the base of the transistor Q2 and pin 1 of the diode D1. A capacitor C12, a resistor R32, an inductor L10, and a capacitor C102 connected in parallel are also connected sequentially to the base of the transistor Q2.

6. The radio frequency feedback circuit for UAV communication according to claim 1, characterized in that: The automatic gain control module includes a chip U8 and an amplifier U18. Pin 3 of the amplifier U18 is connected to pin 13 of the chip U8, pin 4 of the amplifier U18 is connected to pin 3 of the chip U8, pin 1 of the chip U8 is connected to a resistor R360, pin 5 of the chip U8 is connected to a resistor R380, pin 2 of the chip U8 is connected to a resistor R390, and pin 4 of the chip U8 is connected to a resistor R410. Resistors R360, R380, R390, and R410 are all connected to pin 1 of the amplifier U18.

7. The radio frequency feedback circuit for UAV communication according to claim 1, characterized in that: The phase-locked loop module includes amplifier IC6, amplifier IC7, and amplifier IC8. Resistors R207 and R217 are connected to pin 7 of amplifier IC6. Pin 3 of amplifier IC8 is connected between resistors R207 and R217. Resistor R247 is connected between pin 1 of amplifier IC7 and pin 2 of amplifier IC8.

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