CN112713868A

CN112713868A - Network supervisory system

Info

Publication number: CN112713868A
Application number: CN202110016060.2A
Authority: CN
Inventors: 李伟超; 齐云飞; 李琴; 张柳琪; 赵海霞
Original assignee: Zhengzhou University of Aeronautics
Current assignee: Hubei Central China Technology Development Of Electric Power Co ltd
Priority date: 2021-01-07
Filing date: 2021-01-07
Publication date: 2021-04-27
Anticipated expiration: 2041-01-07
Also published as: CN112713868B

Abstract

The invention relates to a network monitoring system, wherein a carrier receiving circuit adopts a tunable receiver to receive a network signal, the network signal is output after frequency-selecting amplification or frequency-selecting and controllable notch amplification, a secondary mixing circuit adopts a first-stage mixing circuit to carry out difference frequency operation on a carrier receiving circuit output signal and a reference carrier signal to generate a difference frequency signal, the difference frequency signal is subjected to feedback frequency modulation to enhance stability, then the difference frequency signal enters a second-stage mixing circuit and the reference carrier signal to carry out sum frequency operation to generate a correct and stable carrier signal to a monitoring host, a small frequency offset compensation circuit acquires a secondary mixing circuit output signal, the small frequency offset compensation circuit acquires the secondary mixing circuit output signal and feeds back the secondary mixing circuit output signal and the first-stage mixing circuit step by step when frequency offset is small, a large frequency offset correction circuit acquires the first-stage mixing circuit output signal, the first-stage mixing circuit output signal, the automatic adaptation to different carrier frequency bands is achieved. The problem that the frequency deviation of network signals influences the accuracy of received signals is effectively solved.

Description

Network supervisory system

Technical Field

The invention relates to the technical field of network supervision, in particular to a network supervision system.

Background

With the frequent occurrence of network security accidents, the national emphasis on network security is continuously deepened. In the prior art, a network analysis platform is mainly used for supervision, and specifically, a network signal (a network signal transmitted through a connection medium such as a cable, a twisted pair, an optical fiber, a microblog, a carrier wave or satellite communication) is collected in real time and transmitted to a monitoring host, and the monitoring host analyzes the received signal, however, the signal transmission is affected by interference of noise and other signals, doppler effect and the like, and network signals transmitted by different connection media have different carrier frequency bands, and if a receiving frequency band adjusted by a receiver does not adapt to the carrier frequency bands of different connection media, the network signal can generate a frequency offset phenomenon to affect the accuracy of the received signal, so that the carrier frequency offset of the received network signal needs to be corrected.

Disclosure of Invention

In view of the above situation, an object of the present invention is to provide a network monitoring system, which effectively solves the problem that the frequency offset of a network signal affects the accuracy of a received signal.

The technical scheme includes that the device comprises a carrier receiving circuit, a secondary mixing circuit, a small frequency offset compensation circuit and a large frequency offset correction circuit, and is characterized in that the carrier receiving circuit receives a network signal by a tunable receiver and outputs the network signal after frequency selection amplification or frequency selection and controllable notch amplification, the secondary mixing circuit performs difference frequency operation on a carrier receiving circuit output signal and a reference carrier signal by a first-stage mixing circuit to generate a difference frequency signal, the difference frequency signal is subjected to feedback frequency modulation to enhance stability and then enters a second-stage mixing circuit and the reference carrier signal to perform sum frequency operation to generate a correct and stable carrier signal to a monitoring host, the small frequency offset compensation circuit acquires a secondary mixing circuit output signal, the small frequency offset compensation circuit feeds back the secondary mixing circuit output signal and the first-stage mixing circuit step by step when frequency offset is small, and the large frequency offset correction circuit acquires a first-stage mixing circuit output signal, after being converted into voltage, the voltage is fed back to the tunable receiver, and the resonant frequency of the tunable receiver is corrected, so that the tunable receiver can automatically adapt to different carrier frequency bands.

The invention has the beneficial effects that: a tunable receiver is adopted to receive a network signal, the network signal is output after frequency-selective amplification or frequency-selective and controllable notch amplification, the phenomenon that the frequency deviation can cause the attenuation of the tuned received signal is utilized, the amplified output signal is output as a direct current signal through a diode average detector, when the amplitude of the direct current signal is normal, a triode Q7 is conducted, a secondary mixing circuit is powered by +5V, when the amplitude of the direct current signal is low, the controllable notch filter notches the signal after the notch frequency selection, namely, the triode Q1 does not amplify the signal, the secondary mixing circuit adopts a first-stage mixing circuit to carry out difference frequency operation on the output signal of a carrier receiving circuit and a reference carrier signal to generate a difference frequency signal, the frequency-selective network is set to carry out frequency selection and then feedback to a grid of a field effect tube Q2 to enhance the stability of the output signal of the first-stage mixing circuit, and then the second-stage mixing circuit and the, generating a correct and stable carrier signal to a monitoring host;

the output signal of the secondary mixing circuit is collected through a frequency selecting circuit, when the frequency deviation is small, the output signal is fed back to the base electrode of a triode Q4 in the secondary mixing circuit through a high-pass filter consisting of a capacitor C12 and an inductor L8 to perform frequency deviation compensation, when the frequency deviation is large, the output signal is fed back to the grid electrode of a field effect tube Q2 in the primary mixing circuit through the high-pass filter consisting of a capacitor C13 and an inductor L9 to perform frequency deviation compensation, so that the secondary mixing circuit generates a stable carrier signal to a monitoring host, the output signal of the primary mixing circuit is collected, the difference frequency signal is converted into voltage and then fed back to a tunable receiver, the resonant frequency of the tunable receiver is corrected, the resonant frequency of the tunable receiver is adapted to the frequency of a network signal transmitted by a connecting medium, and.

Drawings

Fig. 1 is a schematic diagram of the circuit connection of the present invention.

Detailed Description

The foregoing and other technical and scientific aspects, features and utilities of the present invention will be apparent from the following detailed description of the embodiments, which is to be read in connection with the accompanying drawings of fig. 1. The structural contents mentioned in the following embodiments are all referred to the attached drawings of the specification.

Exemplary embodiments of the present invention will be described below with reference to the accompanying drawings.

A network monitoring system comprises a carrier receiving circuit, a secondary mixing circuit, a small frequency offset compensation circuit and a large frequency offset correction circuit, wherein the carrier receiving circuit adopts a tunable receiver to receive network signals, a variable capacitor CP1 and a variable capacitance diode BD1 which are connected in series adjust the frequency to resonate with the frequency band of the received network signals, the frequency is selected through a frequency selection network, a controllable trap filter traps the frequency, then the frequency is amplified in a frequency selection mode or in the frequency selection mode and is output after the controllable trap amplification mode enters a triode Q1 and a resistor R4-a resistor R6, the frequency selection amplification mode and the frequency selection mode are carried out, the secondary mixing circuit adopts a first-stage mixing circuit which consists of a field effect tube Q2, a variable capacitor CP 3-a variable capacitor CP7, a capacitor C5 and an inductor L5 to carry out difference frequency operation on output signals of the carrier receiving circuit and reference carrier signals, a difference frequency signal is generated, wherein the frequency selection network frequency composed of the triode Q3, the capacitors C6 and C18, the inductor L6 and the resistor R7 is, so as to enhance the stability of the output signal of the first-stage mixing circuit, then the output signal enters a second-stage mixing circuit consisting of a triode Q4, a capacitor C8, a C9, a C18, a variable capacitor CP8 and an inductor L7 and a reference carrier signal to perform sum frequency operation, the setting of difference frequency and sum frequency is performed, the anti-interference performance is improved, and a correct and stable carrier signal is generated to a monitoring host, the output signal of the second-stage mixing circuit is collected by a frequency selection circuit through a small frequency offset compensation circuit, when the frequency offset is small (when the national standard connection medium allows the plus or minus 5% of the frequency band offset), the output signal is fed back to the base of a triode Q4 in the second-stage mixing circuit through a high-pass filter consisting of a capacitor C12 and an inductor L8 to perform frequency offset compensation, when the frequency offset is large (when the frequency offset is allowed to be plus or minus 10%), the high-pass filter consisting of a capacitor C13 and an, the large frequency deviation correction circuit collects output signals of the first-stage mixing circuit, the difference frequency signals are converted into voltage through triodes Q6 and Q7, a resistor R10, an electrolytic capacitor E5 and a diode D2 and then fed back to the tunable receiver, the resonant frequency of the tunable receiver is corrected to be adaptive to the frequency of network signals transmitted by a connecting medium, so that the second-stage mixing circuit can generate correct carrier signals, the output signals of the first-stage mixing circuit are collected and converted into voltage and then fed back to the tunable receiver, and the resonant frequency of the tunable receiver is corrected to be adaptive to different carrier frequencies automatically, so that the second-stage mixing circuit can generate correct carrier signals.

On the basis of the scheme, the carrier receiving circuit receives a network signal by using a tunable receiver composed of a transformer T1, a variable capacitor CP1 and a variable-capacitance diode BD1 which are connected in series, the frequency of the tunable receiver is adjusted to be resonant with a receiving network signal frequency band (the network signal is transmitted by a connecting medium such as a cable, a twisted pair, an optical fiber, a microblog, a carrier wave or satellite communication), the frequency of the tunable receiver is selected by a frequency selection network composed of a variable capacitor CP2 and an inductor L1 which are connected in series, a capacitor C1 and an inductor L2 which are connected in parallel, a controllable trap composed of a resistor R1, a resistor R2, capacitors C2 and C3, an inductor L3 and a thyristor VTL1 is then fed into a triode Q1, a resistor R4-a resistor R84 for frequency selection amplification or frequency selection and controllable trap amplification, and then the frequency is output, specifically, the frequency offset can cause the attenuation phenomenon of the tuning receiving signal, and the collector of the Q1 output signal is output through a capacitor C15-C3745-C46 6, The output of a diode average detector consisting of diodes D1 and D3 is a direct current signal, when the amplitude of the direct current signal is normal, a triode Q7 is conducted, +5V supplies power for a secondary mixer circuit, when the amplitude of the direct current signal is low, a photoelectric coupler OP1 is conducted, a thyristor VTL1 is conducted, a controllable trap filter traps the signal after frequency selection of the trapped wave, namely the triode Q1 does not amplify the signal, the detector comprises a transformer T1, one end of a primary coil of the transformer T1 is connected with a communication terminal network signal, the other end of the primary coil of the transformer T1 is connected with ground, one end of a secondary coil of the transformer T1 is connected with one end of a variable capacitor CP1, the other end of the variable capacitor CP1 is connected with the cathode of a variable diode BD1, the anode of the variable diode BD1 is connected with ground, the other end of a secondary coil of the transformer T1 is connected with ground, the middle end of a secondary coil of the transformer T1 is connected with one end of a, the other end of the inductor L1 is connected to one end of a ground capacitor C1, one end of a ground inductor L1 and one end of a resistor R1, the other end of the resistor R1 is connected to one end of a capacitor C2 and one end of a resistor R2, the other end of the resistor R2 is connected to one end of a capacitor C3 and a base of a transistor Q1, the other end of the capacitor C2 is connected to the other end of a capacitor C3 and one end of an inductor L3, the other end of the inductor L3 is connected to an anode of a thyristor VTL1, a cathode of the thyristor VTL1 is connected to ground, an emitter of the transistor Q1 is connected to one end of a resistor R4 and one end of a ground resistor R5, the other end of the resistor R5 is connected to a power supply +15V, a collector of the transistor Q5 is connected to one end of a ground resistor R5, one end of a ground capacitor C5, a collector of the transistor Q5 is connected to a carrier receiving circuit output signal, and the, The negative electrode of the diode D3, the negative electrode of the diode D1 are respectively connected with one end of a grounding capacitor C16 and one end of a resistor R6, the other end of the resistor R6 is connected with the base electrode of a triode Q7, the collector electrode of a triode Q7 is connected with a power supply +5V, the positive electrode of the diode D3 is respectively connected with one end of the grounding capacitor C17 and a pin 2 of a photoelectric coupler OP1, a pin 1 of the photoelectric coupler OP1 is connected with the power supply +0.7V, a pin 4 of the photoelectric coupler OP1 is connected with the power supply +5V, and a pin 3 of the photoelectric coupler OP1 is connected with the control electrode of the thyristor VTL 1.

On the basis of the scheme, the secondary mixing circuit adopts a first-stage mixing circuit consisting of a field effect tube Q2, a variable capacitor CP 3-a variable capacitor CP7, a capacitor C5 and an inductor L5 to carry out difference frequency operation on a carrier receiving circuit output signal and a reference carrier signal to generate a difference frequency signal, wherein a frequency selection network consisting of a triode Q3, capacitors C6 and C18, an inductor L6 and a resistor R7 is arranged to carry out frequency selection and then feed back to a grid electrode of a field effect tube Q2 to enhance the stability of the first-stage mixing circuit output signal, then the first-stage mixing circuit enters a triode Q4, a capacitor C8, a capacitor C9, a capacitor C18, a second-stage mixing circuit consisting of a variable capacitor CP8 and an inductor L7 to carry out sum frequency operation on a reference carrier signal to generate a correct and stable carrier signal to a monitoring host, the field effect tube Q2 is included, and the grid electrode of the field effect tube Q2 is respectively connected with the carrier receiving circuit output signal through a variable capacitor CP3 and, Referring to a carrier signal, a gate of the fet Q2 is connected to one end of the grounded variable capacitor CP5, a source of the fet Q1 is connected to ground, a drain of the fet Q2 is connected to one end of the inductor L4, one end of the inductor L5, one end of the grounded variable capacitor CP6, and one end of the variable capacitor CP7, the other end of the inductor L4 and one end of the grounded capacitor C5 are connected to an emitter of the transistor Q7, the other end of the inductor L5 is connected to the other end of the variable capacitor CP7, one end of the capacitor C7, the other end of the capacitor C7 is connected to one end of the resistor R7 and a base of the transistor Q7, an emitter of the transistor Q7 is connected to ground, a collector of the transistor Q7 is connected to one end of the inductor L7, the other end of the resistor R7 and one end of the capacitor C7, the other end of the inductor L7 is connected to a gate of the capacitor C7, and the other end of the capacitor C, One end of a grounding capacitor C9, one end of a grounding inductor L7 and the base electrode of a triode Q4, the other end of a capacitor C18 is connected with a reference carrier signal, the emitter electrode of the triode Q4 is connected with a power supply of-10V through a resistor R8, and the collector electrode of the triode Q4 is connected to a monitoring host through a grounding variable capacitor CP 1.

On the basis of the above scheme, the small frequency offset compensation circuit collects the output signal of the secondary mixing circuit through a frequency selection circuit composed of a triode Q5, a resistor R9, a capacitor C10 and a capacitor C11 (here, the bandwidth of the frequency selection circuit and the bandwidth of the output signal of the secondary mixing circuit are explained, so that the frequency band of the output signal of the secondary mixing circuit is analyzed by a post-stage circuit), when the frequency offset is small (when the national standard connection medium allows the frequency band deviation to be plus or minus 5%), the output signal is fed back to the base of a triode Q4 in the secondary mixing circuit through a high-pass filter composed of a capacitor C12 and an inductor L8 to perform frequency deviation compensation, when the frequency offset is large (when the frequency band deviation is allowed to be plus or minus 10%), the output signal is fed back to the gate of a field effect tube Q2 in the primary mixing circuit through a high-pass filter composed of a capacitor C13 and an inductor L9 to perform frequency deviation compensation, so that the secondary mixing, the circuit comprises a capacitor C10, wherein one end of the capacitor C10 is connected with a collector of a triode Q4, the other end of the capacitor C10 is respectively connected with a base of a triode Q5, one end of a resistor R9 and one end of a capacitor C11, an emitter of the triode Q5 is connected with the ground, a collector of a triode Q5 is respectively connected with the other end of a resistor R9, the other end of a capacitor C11 and one end of a capacitor C12, the other end of the capacitor C12 is respectively connected with a base of a triode Q4, one end of a grounding inductor L8 and one end of a capacitor C13, the other end of the capacitor C13 is respectively connected with one end of a grounding inductor L9 and one end of a capacitor C14, and the other end of the capacitor C;

the large frequency deviation correction circuit collects output signals of a first-stage mixing circuit, difference frequency signals are converted into voltages through triodes Q6 and Q7, a resistor R10, an electrolytic capacitor E5 and a diode D2 and then fed back to a tunable receiver, the resonant frequency of the tunable receiver is corrected, the voltages are adaptive to network signal frequency bands transmitted by a connecting medium (cables, twisted pairs, optical fibers, microblogs, carrier or satellite communication and the like), and the signals are automatically adaptive to different carrier frequency bands, so that the second-stage mixing circuit generates correct carrier signals, the large frequency deviation correction circuit comprises a triode Q6, a triode Q6, a base electrode of which is connected with the other end of an inductor L5, a collector electrode of a triode Q6 is respectively connected with a negative electrode of the electrolytic capacitor E5 and one end of a resistor R10, the other end of the resistor R10 is connected with a power supply +5V, an anode electrode of an electrolytic capacitor E5 is respectively connected with an anode electrode of a diode D2 and an emitter electrode, The emitter of the transistor Q6 is connected to ground, and the collector of the transistor Q7 is connected to the cathode of the varactor BD 1.

When the invention is used in detail, the carrier receiving circuit receives a network signal by adopting a tunable receiver which is composed of a transformer T1, a variable capacitor CP1 and a variable capacitance diode BD1 which are connected in series, the frequency of the tunable receiver is adjusted to be resonant with the frequency band of the received network signal by the variable capacitor CP1 and the variable capacitance diode BD1 which are connected in series, the frequency of the tunable receiver is selected by a frequency selection network which is composed of the variable capacitor CP2 and the inductance L1 which are connected in series and a capacitor C1 and an inductance L2 which are connected in parallel, a controllable trap which is composed of a resistor R1, a resistor R2, capacitors C2 and C3, an inductance L3 and a thyristor VTL1 is trapped, then the carrier receiving circuit enters a triode Q1 and a resistor R4-resistor R6 for frequency selection amplification or frequency selection and controllable trap amplification and then is output, the carrier receiving circuit enters a secondary mixing circuit and a first-stage mixing circuit which is composed of a field effect tube Q2, a variable capacitor CP 3-a variable, generating a difference frequency signal, wherein a frequency selection network consisting of a triode Q3, capacitors C6 and C18, an inductor L6 and a resistor R7 is arranged to select frequency and feed back to the grid of a field effect tube Q2, so as to enhance the stability of the output signal of a first-stage mixing circuit, then the output signal enters a second-stage mixing circuit consisting of a triode Q4, a capacitor C8, a C9, a C18, a variable capacitor CP8 and an inductor L7 and a reference carrier signal to perform sum frequency operation, so as to generate a correct and stable carrier signal to a monitoring host, a small frequency offset compensation circuit is arranged, the output signal of the second-stage mixing circuit is acquired through the frequency selection circuit consisting of the triode Q5, the resistor R9, the capacitor C10 and the capacitor C11, when the frequency offset is small, the output signal is fed back to the base of the triode Q4 in the second-stage mixing circuit through a high-pass filter consisting of the capacitor C12 and the inductor L8, so as to perform high-pass frequency offset compensation, and when the frequency offset is large, the output signal is fed back to the grid, the frequency deviation compensation is carried out, so that a secondary mixing circuit generates a stable carrier signal to a monitoring host, a large frequency deviation correction circuit is arranged, an output signal of a primary mixing circuit is collected, a difference frequency signal is converted into voltage through a triode Q6 and a Q7, a resistor R10, an electrolytic capacitor E5 and a diode D2 and then fed back to a tunable receiver, the resonant frequency of the tunable receiver is corrected, the voltage is adapted to a network signal frequency transmitted by a connecting medium (such as a cable, a twisted pair, an optical fiber, a microblog, a carrier or satellite communication and the like), the purpose of automatically adapting to different carrier frequencies is achieved, and the problem that the frequency deviation of the network signal and the accuracy of a received signal are influenced is solved by the secondary mixing circuit generating the correct carrier signal.

Claims

1. A network monitoring system comprises a carrier receiving circuit, a secondary mixing circuit, a small frequency offset compensation circuit and a large frequency offset correction circuit, and is characterized in that the carrier receiving circuit adopts a tunable receiver to receive a network signal, the network signal is output after frequency selection amplification or frequency selection and controllable notch amplification, the secondary mixing circuit adopts a first-stage mixing circuit to carry out difference frequency operation on a carrier receiving circuit output signal and a reference carrier signal to generate a difference frequency signal, the difference frequency signal is subjected to feedback frequency modulation to enhance stability, then the difference frequency signal enters a second-stage mixing circuit and the reference carrier signal to carry out sum frequency operation to generate a correct and stable carrier signal to a monitoring host, the small frequency offset compensation circuit acquires a secondary mixing circuit output signal, the second-stage mixing circuit and the first-stage mixing circuit are fed back step by step when frequency offset is small, the large frequency offset correction circuit acquires a first-stage mixing circuit output signal, after being converted into voltage, the voltage is fed back to the tunable receiver, and the resonant frequency of the tunable receiver is corrected, so that the tunable receiver can automatically adapt to different carrier frequency bands.

2. The network supervision system according to claim 1, wherein the carrier receiving circuit comprises a transformer T1, one end of a primary coil of a transformer T1 is connected to the communication terminal network signal, the other end of a primary coil of a transformer T1 is connected to ground, one end of a secondary coil of a transformer T1 is connected to one end of a variable capacitor CP1, the other end of the variable capacitor CP1 is connected to a negative electrode of a varactor BD1, an anode of the varactor BD1 is connected to ground, the other end of a secondary coil of a transformer T1 is connected to ground, a middle end of a secondary coil of a transformer T1 is connected to one end of a variable capacitor CP2, the other end of the variable capacitor CP2 is connected to one end of an inductor L1, the other end of the inductor L1 is connected to one end of a ground capacitor C1, one end of a ground inductor L1 and one end of a resistor R1, the other end of a resistor R1 is connected to one end of a capacitor C2 and one end of a resistor R2, and the, The other end of the transistor Q1 is connected to the other end of the capacitor C2 and the other end of the inductor L3, the other end of the inductor L3 is connected to the anode of the thyristor VTL1, the cathode of the thyristor VTL1 is connected to ground, the emitter of the transistor Q1 is connected to one end of the resistor R4 and one end of the ground resistor R5, the other end of the resistor R4 is connected to +15V, the collector of the transistor Q1 is connected to one end of the ground resistor R6, one end of the ground capacitor C4 and one end of the capacitor C15, the collector of the transistor Q1 is used as a carrier receiving circuit output signal, the other end of the capacitor C15 is connected to the anode of the diode D1 and the cathode of the diode D3, the cathode of the diode D3 is connected to one end of the ground capacitor C3 and one end of the resistor R3, the other end of the resistor R3 is connected to the base of the transistor Q3, the collector of the transistor Q3 is connected to the power supply +5V, and, Pin 2 of the photoelectric coupler OP1, pin 1 of the photoelectric coupler OP1 is connected with +0.7V of a power supply, pin 4 of the photoelectric coupler OP1 is connected with +5V of the power supply, and pin 3 of the photoelectric coupler OP1 is connected with the control electrode of the thyristor VTL 1.

3. The network supervision system according to claim 1, wherein the second-stage mixer circuit comprises a fet Q2, the gate of the fet Q2 is connected to the carrier receiving circuit output signal and the reference carrier signal through a variable capacitor CP3 and a variable capacitor CP4, respectively, the gate of the fet Q2 is connected to one end of a grounded variable capacitor CP5, the source of the fet Q1 is connected to ground, the drain of the fet Q2 is connected to one end of an inductor L4, one end of an inductor L5, one end of a grounded variable capacitor CP6, and one end of a variable capacitor CP7, the other end of the inductor L4 and one end of a grounded capacitor C5 are connected to the emitter of a transistor Q7, the other end of the inductor L5 is connected to the other end of a variable capacitor CP7, one end of a capacitor C7, and one end of a capacitor C8, the other end of a capacitor C7 is connected to one end of a resistor R7, the base of a transistor Q3, and the emitter of the transistor Q3 is, the collector of the triode Q3 is connected to one end of an inductor L6, the other end of a resistor R7 and one end of a capacitor C18, respectively, the other end of an inductor L6, the other end of a capacitor C18 and one end of a grounded capacitor C6 are connected to the gate of a field effect transistor Q2, the other end of a capacitor C8 is connected to one end of a capacitor C18, one end of a grounded capacitor C9, one end of a grounded inductor L7 and the base of a triode Q4, the other end of a capacitor C18 is connected to a reference carrier signal, the emitter of the triode Q4 is connected to a power supply of-10V through a resistor R8, and the collector of the triode Q4 is connected to a monitoring host through a.

4. The network supervision system according to claim 1, wherein the small frequency offset compensation circuit includes a capacitor C10, one end of the capacitor C10 is connected to a collector of a transistor Q4, the other end of the capacitor C10 is connected to a base of a transistor Q5, one end of a resistor R9, and one end of a capacitor C11, an emitter of the transistor Q5 is connected to ground, a collector of a transistor Q5 is connected to the other end of a resistor R9, the other end of a capacitor C11, and one end of a capacitor C12, the other end of a capacitor C12 is connected to a base of a transistor Q4, one end of a grounding inductor L8, and one end of a capacitor C13, the other end of a capacitor C13 is connected to one end of a grounding inductor L9 and one end of a capacitor C14, and the other end of a capacitor C14 is connected to a gate of a fet;

the large frequency deviation correction circuit comprises a triode Q6, the base of a triode Q6 is connected with the other end of an inductor L5, the collector of the triode Q6 is respectively connected with the negative electrode of an electrolytic capacitor E5 and one end of a resistor R10, the other end of the resistor R10 is connected with a power supply +5V, the positive electrode of the electrolytic capacitor E5 is respectively connected with the positive electrode of a diode D2 and the emitter of a triode Q7, the base of the triode Q7, the negative electrode of a diode D2 and the emitter of the triode Q6 are connected with the ground, and the collector of the triode Q7 is connected with the negative electrode of a varactor BD 1.