Broadband small-step low-stray frequency agility frequency source

Abstract

The invention relates to a broadband small-step low-stray frequency agility frequency source. The frequency source comprises a high-performance clock and local oscillation signal generation module, a phase-locked loop module, a switch frequency multiplication filtering module, a voltage presetting module and a high-speed control module, wherein the high-performance clock and local oscillation signal generation module is sequentially connected with the phase-locked loop module and the switching frequency multiplication filtering module, and the voltage presetting module is connected with the phase-locked loop module; the high-speed control module is respectively connected with the voltage presetting module, the phase-locked loop module and the switch frequency multiplication filtering module; a corresponding analog-to-digital converter is introduced into the voltage presetting module, voltage sampling, updating and correction can be carried out in time, a frequency mixer is added into the phase-locked loop module, the loop frequency dividing ratio is reduced in an in-loop frequency mixing mode, and therefore phase noise is optimized. According to the invention, no extra phase-locked loop is needed to generate the local oscillator signal, the complexity and design cost of the circuit are reduced, and miniaturization design is facilitated.

Description

Technical Field

[0001] The invention belongs to the technical field of microwave frequency sources, and in particular relates to a broadband small-step low-spurious agile frequency source. Background Art

[0002] As the basic signal source of modern wireless communication equipment, frequency source plays a vital role in the fields of electronic countermeasures, radar detection and precision measurement. Its performance directly affects the functional realization of many electronic equipment and wireless communication systems. With the development of the times, the application scenarios of frequency sources have become more complex and diverse, and people's requirements for their performance indicators have continued to increase. The main performance indicators of traditional frequency sources include output bandwidth, phase noise, spurious suppression, and agile frequency change time. However, in the actual design process, the optimization design of various indicators is often contradictory and difficult to take into account. Therefore, the mainstream single integrated frequency source chip on the market cannot adapt to certain application scenarios with high performance requirements.

[0003] For example, a broadband fast agile frequency synthesizer disclosed in publication number CN116232320A adopts a voltage preset module and an FPGA control module as core modules, and realizes fast locking of the frequency synthesizer under the control of FPGA parallel data and with the assistance of voltage preset. However, this invention does not take corresponding voltage correction measures in the voltage preset module. When the ambient temperature changes, the voltage-controlled voltage of the VCO in the frequency source will change with the temperature. If the voltage preset correction is not performed in time at this time, the frequency source will not work normally or its performance will degrade. The frequency source scheme uses a digital-to-analog converter and multiple operational amplifiers, which will introduce too much noise to interfere with the output signal phase noise of the frequency source, and the output phase noise is too high. Summary of the invention

[0004] The purpose of the present invention is to provide a broadband small-step low-spurious agile frequency source to address the above problems in the current technology. The present invention introduces a corresponding analog-to-digital converter in the voltage preset module, which can timely perform voltage sampling and update correction, and adds a mixer in the phase-locked loop module to reduce the loop division ratio by mixing in the loop, thereby optimizing the phase noise. The present invention does not need to use an additional phase-locked loop to generate a local oscillator signal, reduces the complexity of the circuit and the design cost, and is conducive to miniaturization design.

[0005] The technical solution of the present invention is: A broadband small-step low-spurious agile frequency source comprises a high-performance clock and local oscillator signal generating module, a phase-locked loop module, a switch frequency multiplication filter module, a voltage preset module, and a high-speed control module; wherein the high-performance clock and local oscillator signal generating module is sequentially connected to the phase-locked loop module and the switch frequency multiplication filter module, and the voltage preset module is connected to the phase-locked loop module; and the high-speed control module is respectively connected to the voltage preset module, the phase-locked loop module, and the switch frequency multiplication filter module; The high-performance clock and local oscillator signal generating module includes a 100MHz constant temperature crystal oscillator, a first doubler, a first amplifier, a quintuple frequency multiplier, a first filter, and a power divider, wherein the 100MHz constant temperature crystal oscillator is connected to the first doubler, the first amplifier, the quintuple frequency multiplier, and the first filter in sequence to output a 1GHz signal, and the power divider divides the 1GHz signal into two paths as input signals of the phase-locked loop module, one path is a clock signal, and the other path is a local oscillator input signal, the clock signal is used as the input signal of the second amplifier in the phase-locked loop module, and the local oscillator signal is used as the input signal of the first tripler in the phase-locked loop module; The phase-locked loop module includes a second amplifier, a DDS, a second filter, a frequency detector, a loop filter, a first operational amplifier, a VCO, a third amplifier, a third filter, a first tripler, a fourth amplifier, a fourth filter, a mixer, a fifth filter, and an attenuator; Among them, the second amplifier, DDS, the second filter, the frequency detector, the loop filter, the first operational amplifier, the VCO, the attenuator, the fifth filter, and the mixer are connected in sequence; the first tripler, the fourth amplifier, the fourth filter, and the mixer are connected in sequence; the mixer is also connected through the third filter, the third amplifier, and the frequency detector.

[0006] The first operational amplifier is in the form of a voltage adder.

[0007] The voltage preset module includes an analog-to-digital converter, a second operational amplifier, a voltage-dividing resistor network, a digital-to-analog converter, and a third operational amplifier; wherein the analog-to-digital converter is connected to the second operational amplifier and the voltage-dividing resistor network; and the digital-to-analog converter is connected to the third operational amplifier; The switch frequency multiplication filter module includes a radio frequency switch, a sixth filter, a fifth amplifier, a second doubler, a seventh filter, a sixth amplifier, a second tripler, an eighth filter, and a seventh amplifier; The input end of the RF switch is connected to the first output end of the VCO in the phase-locked loop module, the first output end of the RF switch is connected to the sixth filter and the fifth amplifier in sequence; the second output end of the RF switch is connected to the second doubler, the seventh filter, and the sixth amplifier in sequence; the third output end of the RF switch is connected to the second tripler, the eighth filter, and the seventh amplifier in sequence.

[0008] The high-speed control module includes a high-speed single-chip microcomputer.

[0009] The high-speed single-chip microcomputer is respectively connected with the DDS, the frequency and phase detector, the analog-to-digital converter, the digital-to-analog converter and the radio frequency switch.

[0010] The essential features of the present invention are: In the high-performance clock and local oscillator signal generating module of the present invention, a 100MHz constant temperature crystal oscillator can simultaneously obtain a high-quality local oscillator signal and a clock signal after passing through a frequency multiplier, an amplifier, a filter, and a power divider, without the need to add a circuit module specifically for generating a local oscillator signal, which is conducive to miniaturization design and cost reduction; in the voltage preset module, there is not only a digital-to-analog converter, which realizes the frequency source's agile frequency conversion function by means of voltage preset, but also an analog-to-digital converter is introduced, which can timely update the voltage preset to ensure that the frequency source can work normally when the working environment changes, and a voltage follower is added after the analog-to-digital converter, which helps to isolate the digital noise and analog noise generated by the analog-to-digital converter; in the phase-locked loop module, not only a direct frequency synthesizer is introduced to drive the phase-locked loop, optimize the output frequency step and fractional spurious, but also a technical method of mixing in the loop is adopted to optimize the phase noise of the output signal; finally, an ultra-wideband, low phase noise, and low spurious output signal is obtained by switching the frequency multiplication filter module. The high-speed control module includes a high-speed single-chip microcomputer, which can realize high-speed data transmission.

[0011] The beneficial effects of the present invention are: (1) Use the output frequency of the DDS as the variable reference input of the phase-locked loop to reduce the frequency output step of the frequency source and avoid fractional spurious.

[0012] (2) The local oscillator signal of the mixer is obtained after the crystal oscillator signal passes through a frequency multiplier, amplifier, filter, and power divider. There is no need to use an additional phase-locked loop to generate the local oscillator signal, which reduces the complexity and design cost of the circuit and is conducive to miniaturization design.

[0013] (3) When the frequency point is changed, the preset voltage generated by the voltage preset module directly causes the frequency source to enter the locking fast capture band, greatly shortening the locking time of the frequency source. The locking time can reach 4 microseconds. When the working environment changes, the preset voltage is corrected in time through the analog-to-digital converter to ensure that the frequency source can work normally.

[0014] (3) The phase-locked loop module adopts the technical solution of in-loop mixing, and the feedback frequency of the VCO is down-converted as the RF input signal of the frequency detector and phase detector, which can greatly reduce the integer division value of the phase-locked loop and optimize the phase noise of the frequency source output signal.

[0015] (4) The switch frequency multiplication and filtering module adopts the technical solution of switch selection output and frequency multiplication, filtering and power amplification to achieve an ultra-wideband frequency output range. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The invention discloses a circuit schematic diagram of a broadband small-step low-spurious agile frequency source.

[0017] Figure 2 It is the circuit schematic diagram of a high-performance clock and local oscillator signal generation module.

[0018] Figure 3 It is the circuit schematic diagram of the phase-locked loop module.

[0019] Figure 4 This is the circuit schematic diagram of the voltage preset module.

[0020] Figure 5 This is the circuit schematic of the switch frequency doubling filter module.

[0021] Figure 6 This is the spurious suppression diagram when the frequency source outputs 6.4GHz.

[0022] Figure 7 It is a time diagram of the frequency hopping from 5.6 GHz to 6.4 GHz. DETAILED DESCRIPTION

[0023] The following is described in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention. It should be noted that in the following description, when the detailed description of known functions and designs may dilute the main content of the present invention, these descriptions will be omitted here.

[0024] like Figure 1 As shown, the present invention is a broadband small-step low-spurious agile frequency source, comprising a high-performance clock and local oscillator signal generating module, a phase-locked loop module, a switch frequency multiplication filter module, a voltage preset module, and a high-speed control module; wherein the high-performance clock and local oscillator signal generating module is sequentially connected to the phase-locked loop module and the switch frequency multiplication filter module, and the voltage preset module is connected to the phase-locked loop module; the high-speed control module is respectively connected to the voltage preset module, the phase-locked loop module, and the switch frequency multiplication filter module; like Figure 2 As shown, the high-performance clock and local oscillator signal generating module includes a 100MHz constant temperature crystal oscillator, a first doubler, a first amplifier, a quintupler, a first filter, and a power divider, wherein the 100MHz constant temperature crystal oscillator is connected to the first doubler, the first amplifier, the quintupler, and the first filter in sequence to output a 1GHz signal, and the power divider divides the 1GHz signal into two paths as input signals of the phase-locked loop module, one path is a clock signal, and the other path is a local oscillator input signal, the clock signal is used as the input signal of the second amplifier in the phase-locked loop module, and the local oscillator signal is used as the input signal of the first tripler in the phase-locked loop module. like Figure 3 As shown, the phase-locked loop module includes a second amplifier, a DDS, a second filter, a frequency detector, a loop filter, a first operational amplifier, a VCO, a third amplifier, a third filter, a first tripler, a fourth amplifier, a fourth filter, a mixer, a fifth filter, and an attenuator; Among them, the second amplifier, DDS, the second filter, the frequency detector, the loop filter, the first operational amplifier, the VCO, the attenuator, the fifth filter, and the mixer are connected in sequence; the first tripler, the fourth amplifier, the fourth filter, and the mixer are connected in sequence; the mixer is also connected through the third filter, the third amplifier, and the frequency detector.

[0025] Furthermore, the first operational amplifier is designed in the form of an adder.

[0026] Furthermore, the input end of the second amplifier is connected to the first output end of the power divider in the high-performance clock and local oscillator signal generating module, and the function of the second amplifier is to amplify the clock signal to a suitable power to drive the DDS to work normally; the input end of the second filter is connected to the output end of the DDS, and the function of the second filter is to filter out the spurious and harmonic signals of the DDS output signal; the reference input end of the frequency detector is connected to the output end of the second filter, and the DDS output signal after filtering out the spurious and harmonic signals is used as the reference input signal of the frequency detector; the input end of the loop filter is connected to the output end of the frequency detector, and the function of the loop filter is to filter out the interference with the main signal. high frequency spurious and noise; the second input end of the first operational amplifier is connected to the output end of the loop filter, and the loop filter outputs a loop voltage signal as the input signal of the second input end of the first operational amplifier; the input end of the VCO is connected to the output end of the first operational amplifier, and the first operational amplifier outputs a total voltage-controlled voltage as the input signal of the VCO. Under the control of the voltage-controlled voltage, the VCO outputs any frequency signal from 5.6 GHz to 6.4 GHz; the input end of the attenuator is connected to the second output end of the VCO, and the function of the attenuator is to perform power attenuation processing on the second output signal of the VCO; the input end of the fifth filter is connected to the output end of the attenuator, and the fifth filter The function of the filter is to filter out the high-frequency harmonics of the second output signal of the VCO; the RF input end of the mixer is connected to the output end of the fifth filter, and the second output signal of the VCO after attenuation filtering is used as the RF input signal of the mixer; the input end of the first triple frequency multiplier is connected to the second output end of the power divider in the high-performance clock and local oscillator signal generating module, and the function of the first triple frequency multiplier is to multiply the 1GHz local oscillator input signal to 3GHz; the input end of the fourth amplifier is connected to the output end of the first triple frequency multiplier, and the function of the fourth amplifier is to power amplify the 3GHz signal; the input end of the fourth filter is connected to the output end of the fourth amplifier, and the function of the fourth filter is In order to filter out the harmonic components caused by the triple frequency; the local oscillator input end of the mixer is connected to the output end of the fourth filter, and the 3GHz signal after filtering is used as the local oscillator input signal of the mixer; the input end of the third filter is connected to the intermediate frequency output end of the mixer, and the function of the third filter is to filter out the stray components of the intermediate frequency output signal of the mixer; the input end of the third amplifier is connected to the output end of the third filter, and the function of the third amplifier is to power amplify the intermediate frequency output signal of the mixer; the radio frequency input end of the frequency detector and the phase detector is connected to the output end of the third amplifier, and the intermediate frequency output signal of the mixer after filtering and amplification is used as the radio frequency input signal of the frequency detector and the phase detector.

[0027] like Figure 4As shown, the voltage preset module includes an analog-to-digital converter, a second operational amplifier, a voltage-dividing resistor network, a digital-to-analog converter, and a third operational amplifier; wherein the analog-to-digital converter is connected to the second operational amplifier and the voltage-dividing resistor network; and the digital-to-analog converter is connected to the third operational amplifier.

[0028] Furthermore, the digital-to-analog converter is of current output type, which has the advantage of shorter voltage establishment time, which helps to reduce the locking time of the frequency source; the second operational amplifier is designed as a voltage follower, and the function of the second operational amplifier is to separate the phase-locked loop module from the analog-to-digital converter to reduce the interference of digital-to-analog noise on the phase-locked loop module; the third operational amplifier is designed as a current-to-voltage conversion circuit, and the function of the third operational amplifier is to convert the output current of the digital-to-analog converter into an output voltage; the voltage-divider resistor network includes two voltage-divider resistors, namely R1 and R2, and the function of the voltage-divider resistor network is to divide the voltage-controlled voltage of the VCO in the phase-locked loop module to facilitate the acquisition of the analog-to-digital converter.

[0029] Furthermore, the analog-to-digital converter is connected to the second operational amplifier and the voltage-divider resistor network in sequence, the voltage-divider resistor network is connected to the input end of the VCO, the voltage-controlled voltage of the VCO is converted into a digital signal after voltage division and used as the input signal of the single-chip microcomputer in the high-speed control module; the output end of the digital-to-analog converter is connected to the input end of the third operational amplifier, the output end of the third operational amplifier outputs a preset voltage and serves as the input signal of the first input end of the first operational amplifier in the phase-locked loop module, and is added to the loop voltage signal output by the loop filter to form a total voltage-controlled voltage to control the output frequency of the VCO, and the preset voltage can allow the frequency source to directly enter the fast capture band, thereby reducing the locking time of the frequency source.

[0030] like Figure 5 As shown, the switch frequency multiplication filter module includes a radio frequency switch, a sixth filter, a fifth amplifier, a second doubler, a seventh filter, a sixth amplifier, a second tripler, an eighth filter, and a seventh amplifier; Furthermore, the input end of the RF switch is connected to the first output end of the VCO in the phase-locked loop module, and the first output end of the RF switch is connected to the sixth filter and the fifth amplifier in sequence; the second output end of the RF switch is connected to the second doubler, the seventh filter, and the sixth amplifier in sequence; the third output end of the RF switch is connected to the second tripler, the eighth filter, and the seventh amplifier in sequence.

[0031] Furthermore, the input end of the RF switch is connected to the first output end of the VCO, and the function of the RF switch is to select different frequency output channels according to actual needs; the input end of the sixth filter is connected to the first output end of the RF switch, and the function of the sixth filter is to filter out the harmonic frequency of the VCO itself; the input end of the fifth amplifier is connected to the output end of the sixth filter, and the function of the fifth amplifier is to amplify the power of the filtered first output signal of the RF switch and output it; the input end of the second doubler is connected to the second output end of the RF switch, and the function of the second doubler is to double the frequency of the second output signal of the RF switch; the input end of the seventh filter is connected to the output end of the second doubler, and the seventh filter The function is to filter out the spurious and harmonic components generated by the double frequency; the input end of the sixth amplifier is connected to the output end of the seventh filter, and the function of the sixth amplifier is to amplify the power of the second output signal of the RF switch after the frequency doubling filter and output it; the input end of the second tripler is connected to the third output end of the RF switch, and the function of the second tripler is to perform triple frequency processing on the third output signal of the RF switch; the input end of the eighth filter is connected to the output end of the second tripler, and the function of the eighth filter is to filter out the spurious and harmonic components generated by the triple frequency; the input end of the seventh amplifier is connected to the output end of the eighth filter, and the function of the seventh amplifier is to amplify the power of the third output signal of the RF switch after the frequency doubling filter and output it.

[0032] Furthermore, the high-speed control module includes a high-speed single-chip microcomputer.

[0033] Furthermore, the high-speed single-chip microcomputer is respectively connected with the DDS, the frequency and phase detector, the analog-to-digital converter, the digital-to-analog converter, and the radio frequency switch.

[0034] Taking the frequency source outputting 6.4GHz signal as an example, the feasibility of this solution is analyzed. Figure 6 This is the spurious suppression diagram when the frequency source outputs 6.4GHz. The maximum spurious value is 79.68dB. The specific data of spurious suppression is obtained by testing with N9030APXA spectrum signal analyzer at room temperature. Figure 7 It is the time required for the frequency source to hop from 5.6GHz to 6.4GHz, which is 4 microseconds. The specific data of the frequency hopping time is obtained by testing using a TBS1102 digital storage oscilloscope at room temperature.

[0035] The software and protocols involved in the present invention are all known technologies.

[0036] In the high-performance clock and local oscillator signal generation module, the 100MHz constant temperature crystal oscillator is connected to the first doubler, the first amplifier, the quintuple frequency, and the first filter in sequence to output a 1GHz signal. The power divider divides the 1GHz signal into two paths as the input signal of the phase-locked loop module. One path is the clock signal, and the other path is the local oscillator input signal. The clock signal is used as the input signal of the second amplifier in the phase-locked loop module, and the local oscillator signal is used as the input signal of the first tripler in the phase-locked loop module.

[0037] In the phase-locked loop module, the second amplifier amplifies the 1GHz clock signal to 0dBm; the DDS outputs a 113.333MHz sine wave signal driven by the 1GHz clock signal; the input end of the second filter is connected to the output end of the DDS, and the function of the second filter is to filter out the spurious and harmonic signals of the DDS output signal; the reference input end of the frequency detector is connected to the output end of the second filter, and the DDS signal after filtering out the spurious and harmonic signals is used as the reference input signal of the frequency detector; the input end of the loop filter is connected to the output end of the frequency detector, and the function of the loop filter is to filter out the high-frequency spurious and noise that interfere with the main signal; the first operation The second input end of the amplifier is connected to the output end of the loop filter; the input end of the VCO is connected to the output end of the first operational amplifier, and the first operational amplifier outputs a total voltage-controlled voltage as the input signal of the VCO. Under the control of the voltage-controlled voltage, the VCO outputs a 6.4 GHz frequency signal; the input end of the attenuator is connected to the second output end of the VCO, and the function of the attenuator is to attenuate the second output signal of the VCO to -10 dBm; the input end of the fifth filter is connected to the output end of the attenuator, and the function of the fifth filter is to filter out the high-frequency harmonics of the second output signal of the VCO; the RF input end of the mixer is connected to the output end of the fifth filter, and the RF input end of the mixer is connected to the output end of the fifth filter. The attenuated filtered VCO second output signal is used as the RF input signal of the mixer; the first tripler frequency multiplier multiplies the 1GHz local oscillator input signal to 3GHz; the input end of the fourth amplifier is connected to the output of the first tripler frequency multiplier, and the function of the fourth amplifier is to amplify the 3GHz signal power to 13dBm; the input end of the fourth filter is connected to the output end of the fourth amplifier, and the function of the fourth filter is to filter out the harmonic components caused by the triple frequency; the local oscillator input end of the mixer is connected to the output end of the fourth filter, and the 3GHz signal after filtering is used as the local oscillator input signal of the mixer; the input end of the third filter is connected to the intermediate frequency output end of the mixer. The third filter is used to filter out the spurious components of the intermediate frequency output signal of the mixer; the input end of the third amplifier is connected to the output end of the third filter, and the function of the third amplifier is to amplify the power of the filtered intermediate frequency output signal of the mixer to -5dBm; the RF input end of the frequency detector is connected to the output end of the third amplifier, and the intermediate frequency output signal of the mixer after filtering and amplification is used as the RF input signal of the frequency detector; at this time, the reference input signal of the frequency detector is 113.333MHz, and the RF input signal is 3.4GHz, so the loop division ratio is 30.

[0038] In the voltage preset module, the output end of the digital-to-analog converter is connected to the input end of the third operational amplifier. The output end of the third operational amplifier outputs a preset voltage and serves as an input signal of the first input end of the first operational amplifier in the phase-locked loop module. After being added to the loop voltage signal output by the loop filter, the total voltage-controlled voltage controls the VCO to output a 6.4GHz frequency signal.

[0039] In the switch frequency multiplication filter module, the input end of the RF switch is connected to the first output end of the VCO; the input end of the sixth filter is connected to the first output end of the RF switch, and the function of the sixth filter is to filter out the harmonic components of the 6.4GHz signal; the input end of the fifth amplifier is connected to the output end of the sixth filter, and the function of the fifth amplifier is to amplify the power of the 6.4GHz frequency signal and output it.

[0040] Matters not covered by the present invention are known technologies.

Claims

1. A broadband small-step low-spurious agile frequency source, characterized by: It includes a high-performance clock and local oscillator signal generating module, a phase-locked loop module, a switch frequency multiplication filter module, a voltage preset module, and a high-speed control module; wherein the high-performance clock and local oscillator signal generating module is sequentially connected to the phase-locked loop module and the switch frequency multiplication filter module, and the voltage preset module is connected to the phase-locked loop module; the high-speed control module is respectively connected to the voltage preset module, the phase-locked loop module, and the switch frequency multiplication filter module; The high-performance clock and local oscillator signal generating module includes a 100MHz constant temperature crystal oscillator, a first doubler, a first amplifier, a quintuple frequency multiplier, a first filter, and a power divider, wherein the 100MHz constant temperature crystal oscillator is connected to the first doubler, the first amplifier, the quintuple frequency multiplier, and the first filter in sequence to output a 1GHz signal, and the power divider divides the 1GHz signal into two paths as input signals of the phase-locked loop module, one path is a clock signal, and the other path is a local oscillator input signal, the clock signal is used as the input signal of the second amplifier in the phase-locked loop module, and the local oscillator signal is used as the input signal of the first tripler in the phase-locked loop module; The phase-locked loop module includes a second amplifier, a DDS, a second filter, a frequency detector, a loop filter, a first operational amplifier, a VCO, a third amplifier, a third filter, a first tripler, a fourth amplifier, a fourth filter, a mixer, a fifth filter, and an attenuator; The second amplifier, DDS, second filter, frequency detector, loop filter, first operational amplifier, VCO, attenuator, fifth filter, and mixer are connected in sequence; the first tripler, fourth amplifier, fourth filter, and mixer are connected in sequence; and the mixer is also connected through the third filter, third amplifier, and frequency detector. The voltage preset module includes an analog-to-digital converter, a second operational amplifier, a voltage-dividing resistor network, a digital-to-analog converter, and a third operational amplifier; wherein the analog-to-digital converter is connected to the second operational amplifier and the voltage-dividing resistor network; and the digital-to-analog converter is connected to the third operational amplifier; The switch frequency multiplication filter module includes a radio frequency switch, a sixth filter, a fifth amplifier, a second doubler, a seventh filter, a sixth amplifier, a second tripler, an eighth filter, and a seventh amplifier; The input end of the RF switch is connected to the first output end of the VCO in the phase-locked loop module, the first output end of the RF switch is connected to the sixth filter and the fifth amplifier in sequence; the second output end of the RF switch is connected to the second doubler, the seventh filter, and the sixth amplifier in sequence; the third output end of the RF switch is connected to the second tripler, the eighth filter, and the seventh amplifier in sequence.

2. The broadband small-step low-spurious agile frequency source as claimed in claim 1, characterized in that: The first operational amplifier is in the form of a voltage adder.

3. The broadband small-step low-spurious agile frequency source according to claim 1, characterized in that: The high-speed control module includes a high-speed single-chip microcomputer.

4. The broadband small-step low-spurious agile frequency source as claimed in claim 3, characterized in that: The high-speed single-chip microcomputer is respectively connected with the DDS, the frequency and phase detector, the analog-to-digital converter, the digital-to-analog converter and the radio frequency switch.

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