A Doppler omnidirectional beacon device for civil aviation equipment

Abstract

The present invention relates to a Doppler omnidirectional beacon device for civil aviation equipment, which includes a signal excitation unit, an amplitude modulation unit, a sideband oscillation unit, a sideband signal power amplifier circuit, and a reference signal power amplifier circuit. The input end of the signal excitation unit is connected to a monitoring antenna, and the output end of the signal excitation unit is connected to the input end of the amplitude modulation module. The sideband signal power amplifier circuit and the reference signal power amplifier circuit are arranged in parallel. The input end of the sideband signal power amplifier circuit is connected to the output end of the amplitude modulation unit through the sideband oscillation unit, and the input end of the reference signal power amplifier circuit is respectively connected to the output end of the amplitude modulation unit. The output end of the sideband signal power amplifier circuit is connected to a sideband antenna, and the output end of the reference signal power amplifier circuit is connected to a reference antenna. The present invention can generate accurate sideband signals and reference signals, improving the safety of civil aviation equipment.

Description

Technical Field

[0001] The present invention relates to the field of electric power technology, and particularly to a Doppler omnidirectional beacon device for civil aviation equipment. Background Art

[0002] As a radio navigation device recommended by the International Civil Aviation Organization, the omnidirectional beacon device is currently mainly applied to the short-range and medium-range guidance work of aircraft. The stable and orderly operation of this radio navigation device can provide effective safety guarantees for the medium and short-range navigation of aircraft. In addition, it can also ensure the normal and stable progress of scientific research flight tests. However, the existing omnidirectional beacon device generates the reference signal and sideband signal by first generating the reference signal through a reference generator and then generating the sideband signal according to the reference signal. In this signal generation method, if an error occurs when generating the reference signal, it will cause errors in the subsequent generated sideband signals, resulting in large signal errors and low accuracy of the omnidirectional beacon device, and unable to guarantee the safety performance of civil aviation equipment. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a Doppler omnidirectional beacon device for civil aviation equipment that can generate accurate sideband signals and reference signals and improve the safety of civil aviation equipment.

[0004] A Doppler omnidirectional beacon device for civil aviation equipment of the present invention includes a signal excitation unit, an amplitude modulation unit, a sideband oscillation unit, a sideband signal power amplifier circuit, and a reference signal power amplifier circuit. The input end of the signal excitation unit is connected to a monitoring antenna, the output end of the signal excitation unit is connected to the input end of the amplitude modulation module, the sideband signal power amplifier circuit and the reference signal power amplifier circuit are arranged in parallel, the input end of the sideband signal power amplifier circuit is connected to the output end of the amplitude modulation unit through the sideband oscillation unit, the input end of the reference signal power amplifier circuit is respectively connected to the output end of the amplitude modulation unit, the output end of the sideband signal power amplifier circuit is connected to a sideband antenna, and the output end of the reference signal power amplifier circuit is connected to a reference antenna;

[0005] The signal excitation unit includes a signal processing circuit, a digital-to-analog conversion circuit, a band-pass filter circuit, a frequency synthesizer circuit, and a clock circuit. The input end of the signal processing circuit is connected to a monitoring antenna, the output end of the signal processing circuit, the digital-to-analog conversion circuit, the band-pass filter circuit, and the frequency synthesizer circuit are connected in sequence, and the clock circuit is respectively connected to the output ends of the signal processing circuit and the digital-to-analog conversion circuit;

[0006] The amplitude modulation unit includes a first amplitude modulation circuit and a second amplitude modulation circuit which are connected in parallel. The input ends of the first amplitude modulation circuit and the second amplitude modulation circuit are respectively connected to the output end of the frequency synthesis circuit. The output end of the first amplitude modulation circuit is respectively connected to the sideband oscillation unit, and the output end of the second amplitude modulation circuit is connected to the reference signal power amplifier circuit;

[0007] The sideband oscillation unit includes an upper sideband oscillator and a lower sideband oscillator which are connected in parallel. The sideband signal power amplifier circuit includes an upper sideband signal power amplifier circuit and a lower sideband signal power amplifier circuit. The upper sideband signal power amplifier circuit is connected to the upper sideband oscillator, and the lower sideband signal power amplifier circuit is connected to the lower sideband oscillator.

[0008] Preferably, the signal excitation unit further includes a power conversion circuit for supplying power to the band-pass filter circuit. The power conversion circuit includes a DC / DC conversion circuit and an LDO filter circuit. The input end of the DC / DC conversion circuit is connected to an external power supply, the output end of the DC / DC conversion circuit is connected to the LDO filter circuit, and the LDO filter circuit is further connected to the band-pass filter circuit.

[0009] In any of the above preferred solutions, the digital-to-analog conversion circuit includes a DAC0830LCM interface circuit and a first operational amplifier. The input end of the DAC0830LCM interface circuit is connected to the signal processing circuit. The first current output end of the DAC0830LCM interface circuit is connected to the inverting end of the first operational amplifier, and the second current output end of the DAC0830LCM interface circuit is connected to the non-inverting end of the first operational amplifier. The output end of the first operational amplifier is connected to the input end of the band-pass filter circuit.

[0010] In any of the above preferred solutions, the band-pass filter circuit includes a second resistor, a third resistor, a feedback resistor, a second operational amplifier, a third capacitor, and a fourth capacitor. One end of the second resistor, the non-inverting end of the second operational amplifier, and one end of the third resistor are respectively connected to the output end of the digital-to-analog conversion circuit. The other end of the second resistor is respectively connected to the other end of the third resistor, one end of the third capacitor, and one end of the fourth capacitor. The other end of the third capacitor is respectively connected to the inverting end of the second operational amplifier and one end of the feedback resistor. The output end of the second operational amplifier and the other end of the feedback resistor are respectively connected to the amplitude modulation circuit.

[0011] Preferably, in any of the above solutions, the first amplitude modulation circuit and the second amplitude modulation circuit both include a first inductor. One end of the first inductor is connected to the output end of the band-pass filter circuit and one end of a first capacitor. The other end of the first capacitor is grounded. The other end of the first inductor is connected to one end of a second capacitor and the negative electrode of a Schottky diode. The other end of the second capacitor is grounded. The positive electrode of the Schottky diode is connected to one end of a first resistor, and the other end of the first resistor is grounded.

[0012] Preferably, in any of the above solutions, the upper sideband signal power amplifier circuit, the lower sideband signal power amplifier circuit, and the reference signal power amplifier circuit all include a first emitter transistor, a second emitter transistor, a fourth resistor, and a fifth resistor. The base of the first emitter transistor is connected to the base of the second emitter transistor. A fourth resistor is connected between the collector and the emitter of the first emitter transistor. The collector of the first emitter transistor is also connected to the first input end of the impedance transformation circuit. The emitter of the first emitter transistor and the collector of the second emitter transistor are both grounded. A fifth resistor is connected between the collector and the emitter of the second emitter transistor.

[0013] Preferably, in any of the above solutions, the signal processing circuit uses an FPGA chip of model EPC1441.

[0014] Preferably, in any of the above solutions, the frequency synthesizer circuit includes a DDS chip, and the DDS chip is connected to the output end of the FPGA chip.

[0015] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0016] 1. The reference signal and the sideband signal are generated in parallel and are independent of each other to prevent relative influence between each signal, reduce signal error, improve signal transmission accuracy, and thus ensure the stable and orderly operation of civil aviation equipment and guarantee safety performance. By providing a band-pass filter circuit, the clutter in the transmitted signal can be filtered out. By providing an amplitude modulation unit, amplitude modulation of the transmitted signal is realized, and the signal is optimized, thereby improving the efficiency and accuracy of the sideband signal and the reference signal transmission.

[0017] 2. The band-pass filter circuit uses a double RC circuit in series to filter out the clutter of the signal and enhance the filtering effect. The second operational amplifier is connected in parallel with a feedback resistor, which can avoid the limitation of the fixed gain bandwidth. By reducing the resistance value of the feedback resistor, it is possible to increase the gain while maintaining a high gain in the loop, reduce the influence of the input bias signal on the output, and reduce the error.

[0018] 3. The power amplifier circuit can amplify the received 5 signals. Two-stage amplification is performed through the first transmitting tube and the second transmitting tube to meet the power requirements for subsequent transmission by the antenna distribution unit. Additionally, when one of the transmitting tubes in the first transmitting tube and the second transmitting tube fails, the other transmitting tube can still amplify the signal, without affecting the subsequent impedance transformation circuit to perform impedance matching transformation on the signal, greatly improving the stability of the entire circuit. Furthermore, by providing an impedance transformation circuit, impedance matching is performed on the amplified signal, enabling the impedance of the signal to match the impedance of the antenna to be transmitted, and the signal has a greater intensity.

[0019] The following further describes a Doppler omnidirectional beacon device for civil aviation equipment according to the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a structural block diagram of a Doppler omnidirectional beacon device for civil aviation equipment according to the present invention;

[0021] Figure 2 is a circuit schematic diagram of the digital-to-analog conversion circuit in a Doppler omnidirectional beacon device for civil aviation equipment according to the present invention;

[0022] Figure 3 is a circuit schematic diagram of the band-pass filter circuit in a Doppler omnidirectional beacon device for civil aviation equipment according to the present invention;

[0023] Figure 4 is a circuit schematic diagram of the first and second amplitude modulation circuits in a Doppler omnidirectional beacon device for civil aviation equipment according to the present invention;

[0024] Figure 5 is a circuit schematic diagram of the power amplifier circuit in a Doppler omnidirectional beacon device for civil aviation equipment according to the present invention;

[0025] Figure 6 is a circuit schematic diagram of the DDS chip in a Doppler omnidirectional beacon device for civil aviation equipment according to the present invention;

[0026] Wherein: 1. Signal processing circuit; 2. Digital-to-analog conversion circuit; 3. Band-pass filter circuit; 4. Frequency synthesizer circuit; 5. First amplitude modulation circuit; 6. Second amplitude modulation circuit; 7. Upper sideband oscillator; 8. Upper sideband signal power amplifier circuit; 9. Lower sideband oscillator; 10. Upper sideband signal power amplifier circuit; 11. Reference signal power amplifier circuit; 12. Clock circuit. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] As Figure 1As shown in the figure, the present invention provides a Doppler omnidirectional beacon device for civil aviation equipment, including a signal excitation unit, an amplitude modulation unit, a sideband oscillation unit, a sideband signal power amplifier circuit, and a reference signal power amplifier circuit 11. The input end of the signal excitation unit is connected to the monitoring antenna, the output end of the signal excitation unit is connected to the input end of the amplitude modulation module, the sideband signal power amplifier circuit and the reference signal power amplifier circuit 11 are arranged in parallel. The input end of the sideband signal power amplifier circuit is connected to the output end of the amplitude modulation unit through the sideband oscillation unit, the input end of the reference signal power amplifier circuit 11 is respectively connected to the output end of the amplitude modulation unit, the output end of the sideband signal power amplifier circuit is connected to the sideband antenna, and the output end of the reference signal power amplifier circuit 11 is connected to the reference antenna.

[0028] In this embodiment, the signal excitation unit receives the signal of the monitoring antenna, performs conversion processing on the antenna signal, and generates 1 reference signal and 4 sideband signals. The amplitude modulation unit adjusts the amplitudes of the received original 5 signals to 5 signals with the required amplitudes. The 4 sideband signals after amplitude modulation are modulated by the sideband oscillation unit to generate corresponding modulation signals, which are amplified by the sideband signal power amplifier circuit. The 1 reference signal after amplitude modulation is amplified by the reference signal power amplifier circuit 11. The 4 sideband signals and the 1 reference signal are amplified to the transmitted power. The 4 sideband signals are fed for transmission through the sideband antenna, and the 1 reference signal is fed for transmission through the reference antenna.

[0029] Specifically, the signal excitation unit includes a signal processing circuit 1, a digital-to-analog conversion circuit 2, a band-pass filter circuit 3, a frequency synthesizer circuit 4, and a clock circuit 12. The input end of the signal processing circuit 1 is connected to the monitoring antenna, and the output end of the signal processing circuit 1, the digital-to-analog conversion circuit 2, the band-pass filter circuit 3, and the frequency synthesizer circuit 4 are connected in sequence. The clock circuit 12 is respectively connected to the output ends of the signal processing circuit 1 and the digital-to-analog conversion circuit 2. The amplitude modulation unit includes a first amplitude modulation circuit 5 and a second amplitude modulation circuit 6 arranged in parallel. The input ends of the first amplitude modulation circuit 5 and the second amplitude modulation circuit 6 are respectively connected to the output end of the frequency synthesizer circuit 4. The output end of the first amplitude modulation circuit 5 is respectively connected to the sideband oscillation unit, and the output end of the second amplitude modulation circuit 6 is connected to the reference signal power amplifier circuit 11. The sideband oscillation unit includes an upper sideband oscillator 7 and a lower sideband oscillator 9 arranged in parallel. The sideband signal power amplifier circuit includes an upper sideband signal power amplifier circuit 108 and a lower sideband signal power amplifier circuit. The upper sideband signal power amplifier circuit 108 is connected to the upper sideband oscillator 7, and the lower sideband signal power amplifier circuit is connected to the lower sideband oscillator 9.

[0030] The signal processing circuit 1 receives the signals from the monitoring antenna, converts and processes the antenna signals to generate digital signals. The digital-to-analog conversion circuit 2 converts the received digital signals into analog signals, and the band-pass filter circuit 3 filters out the clutter in the analog signals. The analog signal after filtering out the clutter is processed by the frequency synthesizer circuit 4 to generate an upper sideband signal, a lower sideband signal, and a reference signal. Among them, the upper sideband signal and the lower sideband signal are respectively provided with a first amplitude modulation circuit 5. After the upper sideband signal and the lower sideband signal are respectively amplitude-clamped by the first amplitude modulation circuit 5, the upper sideband signal and the lower sideband signal are respectively screened by the sideband oscillation unit, so that the upper sideband signal is transmitted to the upper sideband signal power amplifier circuit 108 through the upper sideband oscillator 7 for power amplification, and the lower sideband signal is transmitted to the lower sideband signal power amplifier circuit through the lower sideband oscillator 9 for power amplification. The amplified upper and lower sideband signals are transmitted by the sideband antenna. The reference signal should be provided with a second amplitude modulation circuit 6. After the reference signal is amplitude-clamped by the second amplitude modulation circuit 6, it is power-amplified by the reference signal power amplifier circuit 11, and the amplified reference signal is transmitted by the reference antenna. In addition, the clock circuit 12 can provide a reference clock.

[0031] In the present invention, the reference signal and the sideband signal are generated in parallel and are independent of each other to prevent relative influence between the signals of each path, reduce signal errors, improve the accuracy of signal transmission, and thus ensure the stable and orderly operation of civil aviation equipment and guarantee the safety performance. By providing the band-pass filter circuit 3, the clutter in the transmitted signal can be filtered out. By providing the amplitude modulation unit, the amplitude modulation of the transmitted signal is realized, and the signal is optimized, thereby improving the efficiency and accuracy of the transmission of the sideband signal and the reference signal.

[0032] Furthermore, the signal excitation unit further includes a power conversion circuit for supplying power to the band-pass filter circuit 3. The power conversion circuit includes a DC / DC conversion circuit and an LDO filter circuit. The input end of the DC / DC conversion circuit is connected to an external power supply, the output end of the DC / DC conversion circuit is connected to the LDO filter circuit, and the LDO filter circuit is further connected to the band-pass filter circuit 3. The voltage provided by the external power supply is converted by the DC / DC conversion circuit and the required voltage is output to supply power to the band-pass filter circuit 3.

[0033] Furthermore, as Figure 2 shown, the digital-to-analog conversion circuit 2 includes a DAC0830LCM interface circuit and a first operational amplifier AR1. The input end of the DAC0830LCM interface circuit is connected to the signal processing circuit 1. The first current output end of the DAC0830LCM interface circuit is connected to the inverting end of the first operational amplifier AR1. The second current output end of the DAC0830LCM interface circuit is connected to the non-inverting end of the first operational amplifier AR1. The output end of the first operational amplifier AR1 is connected to the input end of the band-pass filter circuit 3.

[0034] Further, as Figure 3 shown, the band-pass filter circuit 3 includes a second resistor R2, a third resistor R3, a feedback resistor RF, a second operational amplifier AR2, a third capacitor C3, and a fourth capacitor C4. One end of the second resistor R2, the non-inverting terminal of the second operational amplifier, and one end of the third resistor R3 are respectively connected to the output terminal of the digital-to-analog conversion circuit 2. The other end of the second resistor R2 is respectively connected to the other end of the third resistor R3, one end of the third capacitor C3, and one end of the fourth capacitor C4. The other end of the third capacitor C3 is respectively connected to the inverting terminal of the second operational amplifier AR2 and one end of the feedback resistor RF. The output terminal of the second operational amplifier AR2 and the other end of the feedback resistor RF are respectively connected to the amplitude modulation circuit. By using a double RC circuit in series to filter out the clutter of the signal, the filtering effect is enhanced. The second operational amplifier AR2 is shunted with a feedback resistor RF, which can avoid the limitation of the fixed gain bandwidth. By reducing the resistance value of the feedback resistor RF, it is possible to achieve high loop gain while increasing the gain, reduce the influence of the input offset signal on the output, and reduce the error.

[0035] Further, both the first amplitude modulation circuit 5 and the second amplitude modulation circuit 6 adopt the circuit as Figure 4 shown. Among them, the first amplitude modulation circuit 5 is taken as an example for illustration. The first amplitude modulation circuit 5 includes a first inductor L1. One end of the first inductor L1 is connected to the output terminal of the band-pass filter circuit 3 and one end of the first capacitor C1. The other end of the first capacitor C1 is grounded. The other end of the first inductor L1 is connected to one end of the second capacitor C2 and the negative electrode of the Schottky diode D1. The other end of the second capacitor C2 is grounded. The positive electrode of the Schottky diode D1 is connected to one end of the first resistor R1. The other end of the first resistor R1 is grounded. Through the above inductor and capacitor combination LC network, the 4-channel sideband signals transmitted by the band-pass filter are filtered and adjusted. Then, the amplitude of the sideband signal is further clamped by using a Schottky diode. According to the required amplitude, the parameter values of the diode and the resistor R1 are selected, and then the amplitude modulation of the above sideband signal is realized, so that the sideband signal is adjusted to the required value, which is convenient for subsequent signal amplification processing, thereby improving the efficiency and accuracy of sideband signal transmission.

[0036] Similarly, through the above inductor and capacitor combination LC network, the 1-channel reference signal transmitted by the band-pass filter is filtered and adjusted. Then, the amplitude of the reference signal is further clamped by using a Schottky diode. According to the required amplitude, the parameter values of the diode and the resistor R1 are selected, and then the amplitude modulation of the above reference signal is realized, so that the reference signal is adjusted to the required value, which is convenient for subsequent signal amplification processing, thereby improving the efficiency and accuracy of reference signal transmission.

[0037] Further, the upper sideband signal power amplifier circuit 108, the lower sideband signal power amplifier circuit, and the reference signal power amplifier circuit 11 all adopt the same asFigure 5 As shown in the figure. Taking the upper sideband signal power amplifier circuit 108 as an example, it includes a first transmitting tube Q1, a second transmitting tube Q2, a fourth resistor R4, and a fifth resistor R5. The base of the first transmitting tube Q1 is connected to the base of the second transmitting tube Q2. A fourth resistor R4 is connected between the collector and the emitter of the first transmitting tube Q1. The collector of the first transmitting tube Q1 is also connected to the first input end of the impedance transformation circuit. The emitter of the first transmitting tube Q1 and the collector of the second transmitting tube Q2 are both grounded. A fifth resistor R5 is connected between the collector and the emitter of the second transmitting tube Q2.

[0038] The power amplifier circuit in this structure can amplify the received 5 - way signals. Two - stage amplification is carried out through the first transmitting tube Q1 and the second transmitting tube Q2 to meet the power requirements for the subsequent antenna distribution unit to transmit. In addition, when one of the transmitting tubes in the first transmitting tube Q1 and the second transmitting tube Q2 fails, the other transmitting tube can still amplify the signal, without affecting the output of the subsequent signal, greatly improving the stability of the entire circuit.

[0039] Further, the signal processing circuit 1 uses an FPGA chip of model EPC1441.

[0040] Further, the frequency synthesizer circuit 4 includes a DDS chip. As Figure 6 shown in the circuit schematic diagram of the DDS chip. The DDS chip is connected to the output end of the FPGA chip. The DDS chip consists of a reference crystal oscillator, a frequency discriminator and phase comparator, a loop filter, a voltage - controlled oscillator, and a frequency divider, etc. The reference frequency of the phase discriminator in the phase - locked loop is obtained by dividing the crystal oscillator frequency by M. The feedback signal of the voltage - controlled oscillator is sent to the phase discriminator through a variable frequency divider for phase comparison. The error signal output by the phase discriminator is sent to the control end of the voltage - controlled oscillator through a loop low - pass filter.

[0041] The embodiments described above are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A Doppler omnidirectional beacon device for civil aviation equipment, characterized in that: It includes a signal excitation unit, an amplitude modulation unit, a sideband oscillation unit, a sideband signal power amplifier circuit and a reference signal power amplifier circuit. The input end of the signal excitation unit is connected to the monitoring antenna, the output end of the signal excitation unit is connected to the input end of the amplitude modulation module, the sideband signal power amplifier circuit and the reference signal power amplifier circuit are arranged in parallel, the input end of the sideband signal power amplifier circuit is connected to the output end of the amplitude modulation unit through the sideband oscillation unit, the input end of the reference signal power amplifier circuit is respectively connected to the output end of the amplitude modulation unit, the output end of the sideband signal power amplifier circuit is connected to the sideband antenna, and the output end of the reference signal power amplifier circuit is connected to the reference antenna; The signal excitation unit includes a signal processing circuit, a digital-to-analog conversion circuit, a band-pass filter circuit, a frequency synthesizer circuit and a clock circuit. The input end of the signal processing circuit is connected to the monitoring antenna, the output end of the signal processing circuit, the digital-to-analog conversion circuit, the band-pass filter circuit and the frequency synthesizer circuit are connected in sequence, and the clock circuit is respectively connected to the output ends of the signal processing circuit and the digital-to-analog conversion circuit; The amplitude modulation unit includes a first amplitude modulation circuit and a second amplitude modulation circuit arranged in parallel. The input ends of the first amplitude modulation circuit and the second amplitude modulation circuit are respectively connected to the output end of the frequency synthesizer circuit. The output end of the first amplitude modulation circuit is respectively connected to the sideband oscillation unit, and the output end of the second amplitude modulation circuit is connected to the reference signal power amplifier circuit; The sideband oscillation unit includes an upper sideband oscillator and a lower sideband oscillator arranged in parallel. The sideband signal power amplifier circuit includes an upper sideband signal power amplifier circuit and a lower sideband signal power amplifier circuit. The upper sideband signal power amplifier circuit is connected to the upper sideband oscillator, and the lower sideband signal power amplifier circuit is connected to the lower sideband oscillator; The digital-to-analog conversion circuit includes a DAC0830LCM interface circuit and a first operational amplifier. The input end of the DAC0830LCM interface circuit is connected to the signal processing circuit. The first current output end of the DAC0830LCM interface circuit is connected to the inverting end of the first operational amplifier. The second current output end of the DAC0830LCM interface circuit is connected to the non-inverting end of the first operational amplifier. The output end of the first operational amplifier is connected to the input end of the band-pass filter circuit; The band-pass filter circuit includes a second resistor, a third resistor, a feedback resistor, a second operational amplifier, a third capacitor and a fourth capacitor. One end of the second resistor, the non-inverting end of the second operational amplifier and one end of the third resistor are respectively connected to the output end of the digital-to-analog conversion circuit. The other end of the second resistor is respectively connected to the other end of the third resistor, one end of the third capacitor and one end of the fourth capacitor. The other end of the third capacitor is respectively connected to the inverting end of the second operational amplifier and one end of the feedback resistor. The output end of the second operational amplifier and the other end of the feedback resistor are respectively connected to the amplitude modulation circuit; Both the first amplitude modulation circuit and the second amplitude modulation circuit include a first inductor. One end of the first inductor is connected to the output end of the band-pass filter circuit and one end of a first capacitor. The other end of the first capacitor is grounded. The other end of the first inductor is connected to one end of a second capacitor and the cathode of a Schottky diode. The other end of the second capacitor is grounded. The anode of the Schottky diode is connected to one end of a first resistor, and the other end of the first resistor is grounded; Both the upper sideband signal power amplifier circuit, the lower sideband signal power amplifier circuit, and the reference signal power amplifier circuit include a first emitter transistor, a second emitter transistor, a fourth resistor, and a fifth resistor. The base of the first emitter transistor is connected to the base of the second emitter transistor. A fourth resistor is connected between the collector and the emitter of the first emitter transistor. The collector of the first emitter transistor is further connected to the first input end of the impedance transformation circuit. The emitter of the first emitter transistor and the collector of the second emitter transistor are both grounded. A fifth resistor is connected between the collector and the emitter of the second emitter transistor; The signal processing circuit uses an FPGA chip of model EPC1441; The frequency synthesizer circuit includes a DDS chip, and the DDS chip is connected to the output end of the FPGA chip.

2. A Doppler omnidirectional beacon device for civil aviation equipment according to claim 1, characterized in that: The signal excitation unit further includes a power conversion circuit for supplying power to the band-pass filter circuit. The power conversion circuit includes a DC / DC conversion circuit and an LDO filter circuit. The input end of the DC / DC conversion circuit is connected to an external power supply. The output end of the DC / DC conversion circuit is connected to the LDO filter circuit, and the LDO filter circuit is further connected to the band-pass filter circuit.

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