Satellite-borne ultra-low phase noise broadband frequency hopping frequency source circuit and control method

Abstract

The invention discloses a spaceborne ultra-low phase noise broadband frequency hopping frequency source circuit and a control method, which are used for realizing ultra-low phase noise output and broadband frequency hopping output of the frequency source circuit, the spaceborne ultra-low phase noise broadband frequency hopping frequency source circuit comprises a constant temperature crystal oscillator, and two ends of the constant temperature crystal oscillator are respectively connected with a main ring and an auxiliary ring; the main ring comprises a first digital phase discriminator, a first loop filter, a multi-path integrated coaxial dielectric oscillator, a driving amplifier, a balanced mixer, an intermediate frequency amplifier and a low-pass filter; the main ring and the auxiliary ring both use coaxial dielectric oscillators, the dielectric oscillator of the main ring is integrated in a multi-path mode, meanwhile, switching among different channels can be conducted through control signals, oscillation starting circuits of the dielectric oscillators of the different channels are switched for power supply during switching, and the requirement for output ultra-low phase noise is met; by arranging the frequency control circuit, frequency hopping output frequency control within a certain frequency bandwidth is achieved, and the technical problem that in the prior art, an ultra-low phase noise index and broadband frequency hopping output of a frequency source circuit cannot be met at the same time is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of microwave circuits, and in particular is a satellite-borne ultra-low phase noise broadband frequency hopping frequency source circuit and a control method. Background Art

[0002] With the continuous development of communication satellite technology, the requirements for onboard frequency sources are mainly reflected in two points: first, the phase noise characteristics of the frequency source circuit output frequency are increasingly required, and second, the frequency source circuit signal is required to be able to achieve flexible frequency hopping switching through control instructions on orbit. However, the low phase noise requirements of the frequency source circuit signal and broadband frequency hopping are relatively contradictory in the frequency source implementation technology. At present, the implementation of the onboard ultra-low phase noise frequency source is basically implemented by a digital phase-locked / sampling phase-locked medium oscillator circuit, which cannot achieve broadband frequency hopping output; and the broadband frequency hopping frequency source circuit is basically implemented based on a dual digital phase-locked loop phase-locked voltage-controlled oscillator, and the frequency switching is generally controlled by serial port instructions. This circuit cannot achieve the ultra-low phase noise requirements of the output frequency point.

[0003] In addition, the above two solutions cannot meet the application scenarios of using discrete instruction control while taking into account frequency hopping output and ultra-low phase noise. Summary of the invention

[0004] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a satellite-borne ultra-low phase noise broadband frequency hopping frequency source circuit and a control method to solve the technical problem in the prior art that the ultra-low phase noise index and broadband frequency hopping output of the frequency source circuit cannot be met simultaneously.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:

[0006] A satellite-borne ultra-low phase noise broadband frequency hopping frequency source circuit is used to achieve ultra-low phase noise output and broadband frequency hopping output of the frequency source circuit, comprising a constant temperature crystal oscillator, wherein two ends of the constant temperature crystal oscillator are respectively connected to a main ring and an auxiliary ring;

[0007] The main loop includes a first digital phase detector, a first loop filter, a multi-channel integrated coaxial dielectric oscillator, a driving amplifier, a balanced mixer, an intermediate frequency amplifier and a low-pass filter; the first digital phase detector is connected to the loop filter and the third input end of the multi-channel integrated coaxial dielectric oscillator in sequence; the first output end of the multi-channel integrated coaxial dielectric oscillator is connected to the driving amplifier, the balanced mixer, the intermediate frequency amplifier and the low-pass filter in sequence; the output end of the low-pass filter is connected to the first digital phase detector; the second output end of the multi-channel integrated coaxial dielectric oscillator serves as a signal output port;

[0008] The auxiliary loop includes a second digital phase detector, a second loop filter and a coaxial dielectric oscillator which are connected in sequence; the first output end of the coaxial dielectric oscillator is connected to the balanced mixer, and the second output end of the coaxial dielectric oscillator is connected to the second digital phase detector;

[0009] It also includes a frequency control circuit, wherein a first output terminal of the frequency control circuit is connected to the first digital phase detector, and a second output terminal and a third output terminal of the frequency control circuit are respectively connected to a first input terminal and a second input terminal of the multi-channel integrated coaxial dielectric oscillator;

[0010] The constant temperature crystal oscillator generates two crystal oscillation signals with the same frequency and equal amplitude through oscillation, and sends the two crystal oscillation signals to the first digital phase detector and the second digital phase detector respectively;

[0011] The first digital phase detector receives a control signal from the frequency control circuit, performs phase detection on a crystal oscillation signal sent by a constant temperature crystal oscillator and an intermediate frequency signal amplified by an intermediate frequency amplifier and filtered by a low-pass filter, and sends an output locking voltage to a first loop filter;

[0012] The first loop filter performs integral filtering on the locking voltage to generate an integral filtered locking voltage, and sends the integral filtered locking voltage to the voltage control end of the multi-channel integrated coaxial dielectric oscillator;

[0013] The multi-channel integrated coaxial dielectric oscillator oscillates and generates two channels of locking signals with the same frequency and amplitude under the control of the locking voltage. One channel of locking signal is used as the output of the satellite-borne ultra-low phase noise broadband frequency hopping frequency source circuit, and the other channel of locking signal is sent to the driving amplifier. The driving amplifier amplifies the locking signal power to the excitation level required by the balanced mixer and then sends it to the local oscillator port of the balanced mixer as the local oscillator signal required by the balanced mixer, and selects the channel through the control signal.

[0014] The second digital phase detector is used to perform phase detection on the crystal oscillation signal sent by the constant temperature crystal oscillator and the radio frequency signal sent by the coaxial dielectric oscillator, and send the output locking voltage to the second loop filter;

[0015] The second loop filter performs integral filtering on the locking voltage to generate an integral filtered locking voltage, and sends the integral filtered locking voltage to the voltage control end of the coaxial dielectric oscillator;

[0016] The coaxial dielectric oscillator oscillates and generates a locking signal under the control of a locking voltage, and feeds the locking signal as a radio frequency signal into a balanced mixer and a second digital phase detector;

[0017] The balanced mixer is used to mix the local oscillator signal output by the main loop and the radio frequency signal output by the auxiliary loop to obtain a difference frequency signal, and obtain an intermediate frequency signal after the difference frequency signal is amplified by an intermediate frequency amplifier and filtered by a low-pass filter, and the intermediate frequency signal is sent to the first digital phase detector;

[0018] The frequency control circuit is used to convert the discrete instructions input from the outside into the channel selection control signal of the multi-channel integrated coaxial dielectric oscillator of the main loop and the setting control level signal of the first digital phase detector, and send the channel selection control signal and the setting control level signal as control signals to the multi-channel integrated coaxial dielectric oscillator and the first digital phase detector respectively.

[0019] The present invention also includes the following technical features:

[0020] The first digital phase detector includes an M frequency divider and a phase detector, the M frequency divider is connected to the frequency control circuit and the low-pass filter respectively, and the phase detector is connected to the constant temperature crystal oscillator and the first loop filter respectively.

[0021] The frequency control circuit includes an optical coupler, a decoder and a data selector connected in sequence;

[0022] The optical coupler is used to perform photoelectric conversion on discrete instructions input from the outside;

[0023] The decoder is used to convert the discrete instructions after photoelectric conversion into parallel control signals, and the parallel control signals are divided into two paths, one of which is used as the channel selection control signal of the multi-channel integrated coaxial dielectric oscillator of the main loop, and the other is used as the input signal of the data selector;

[0024] The data selector is used to convert the parallel control signal output by the decoder into a setting control level signal of the M divider of the phase detector corresponding to the required frequency point. The setting control level signal is connected to the setting end of the M divider of the first phase detector of the main loop as a control signal.

[0025] The phase detection frequency of the second digital phase detector is an integer frequency point above 50 MHz.

[0026] The multi-channel integrated coaxial dielectric oscillator includes four ports, wherein the first port and the second port are both control ports, which are used to receive control instructions from the frequency control circuit, and then select different channels; the third port is a voltage-controlled voltage input port, which is used to adjust the output frequency of the fourth port according to the voltage-controlled voltage output by the first loop filter; the fourth port is a radio frequency output port, which is used to output the final output frequency, and at the same time couple a part of the output radio frequency signal through a coupler, and the output radio frequency signal is amplified by a driving amplifier as a local oscillator signal of a balanced mixer.

[0027] A method for using a spaceborne ultra-low phase noise broadband frequency hopping frequency source circuit, specifically including the following steps:

[0028] Step 1, when the loop of the main loop reaches the lock of the digital phase-locked loop, the locking voltage output by the first digital phase detector is sent to the first loop filter. The first loop filter integrates and filters the locking voltage to generate an integrated and filtered locking voltage, and sends this integrated and filtered locking voltage to the voltage-controlled terminal of the multi-channel integrated coaxial dielectric oscillator. Under the control of the locking voltage, the multi-channel integrated coaxial dielectric oscillator oscillates to generate two locking signals with the same frequency and equal amplitude. One locking signal is used as the output of this spaceborne ultra-low phase noise broadband frequency hopping frequency source circuit, and the other locking signal is sent to the drive amplifier. The drive amplifier amplifies the power of the locking signal to the excitation level required by the balanced mixer and then serves as the local oscillator signal required by the balanced mixer and is sent to the local oscillator port of the balanced mixer;

[0029] Step 2, when the loop of the auxiliary loop reaches the lock of the digital phase-locked loop, the locking voltage output by the second digital phase detector is sent to the second loop filter. The second loop filter integrates and filters the locking voltage to generate an integrated and filtered locking voltage and sends it to the voltage-controlled terminal of the coaxial dielectric oscillator. The locking signal generated by the coaxial dielectric oscillator under the control of the locking voltage is fed into the balanced mixer and the second digital phase detector as the radio frequency signal;

[0030] Step 3, the balanced mixer mixes the received local oscillator signal and radio frequency signal to obtain a difference frequency signal. The difference frequency signal is amplified by the intermediate frequency amplifier and filtered by the low-pass filter to obtain an intermediate frequency signal, and this intermediate frequency signal is sent to the first digital phase detector.

[0031] Compared with the prior art, the beneficial technical effects of the present invention are:

[0032] (Ⅰ) In the present invention, both the main loop and the auxiliary loop use coaxial dielectric oscillators. The dielectric oscillator of the main loop is multi-channel integrated, and at the same time, it can be switched between different channels through a control signal. When switching, the power supply of the starting circuit of the dielectric oscillator in different channels is switched, so as to meet the requirements of ultra-low phase noise of the output. At the same time, by setting a frequency control circuit, the frequency hopping output frequency control within a certain frequency bandwidth is realized, and the technical problem that the ultra-low phase noise index and broadband frequency hopping output of the frequency source circuit in the prior art cannot be satisfied at the same time is solved.

[0033] (Ⅱ) In the present invention, through the flexible configuration of the decoder and the data selector, the frequency hopping output frequency control within a certain frequency bandwidth is realized. This control method does not require software configuration and only needs discrete control execution to realize frequency switching.

[0034] (III) The control circuit of the present invention uses an optocoupler as an anti-interference functional device, which can effectively prevent the control circuit from malfunctioning due to interference in the complex EMC environment inside the satellite. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a block diagram of the frequency source circuit proposed by the present invention;

[0036] Figure 2 It is a structural diagram of a frequency source circuit adopting the design concept of the present invention.

[0037] The specific contents of the present invention are further explained in detail below in conjunction with embodiments. DETAILED DESCRIPTION

[0038] It should be noted that, unless otherwise specified, all components in the present invention are components known in the art.

[0039] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0040] The present invention provides a satellite-borne ultra-low phase noise broadband frequency hopping frequency source circuit, which is used to achieve ultra-low phase noise output and broadband frequency hopping output of the frequency source circuit, and comprises a constant temperature crystal oscillator, wherein two ends of the constant temperature crystal oscillator are respectively connected to a main ring and an auxiliary ring;

[0041] The main loop includes a first digital phase detector, a first loop filter, a multi-channel integrated coaxial dielectric oscillator, a driving amplifier, a balanced mixer, an intermediate frequency amplifier and a low-pass filter; the first digital phase detector is connected to the loop filter and the third input end of the multi-channel integrated coaxial dielectric oscillator in sequence; the first output end of the multi-channel integrated coaxial dielectric oscillator is connected to the driving amplifier, the balanced mixer, the intermediate frequency amplifier and the low-pass filter in sequence; the output end of the low-pass filter is connected to the first digital phase detector; the second output end of the multi-channel integrated coaxial dielectric oscillator serves as a signal output port;

[0042] The auxiliary loop includes a second digital phase detector, a second loop filter and a coaxial dielectric oscillator which are connected in sequence; the first output end of the coaxial dielectric oscillator is connected to the balanced mixer, and the second output end of the coaxial dielectric oscillator is connected to the second digital phase detector;

[0043] It also includes a frequency control circuit, wherein a first output terminal of the frequency control circuit is connected to a first digital phase detector, and a second output terminal and a third output terminal of the frequency control circuit are respectively connected to a first input terminal and a second input terminal of a multi-channel integrated coaxial dielectric oscillator;

[0044] The constant temperature crystal oscillator generates two crystal oscillation signals with the same frequency and equal amplitude through oscillation, and sends the two crystal oscillation signals to the first digital phase detector and the second digital phase detector respectively;

[0045] The first digital phase detector receives a control signal from the frequency control circuit, performs phase detection on a crystal oscillation signal sent by a constant temperature crystal oscillator and an intermediate frequency signal amplified by an intermediate frequency amplifier and filtered by a low-pass filter, and sends an output locking voltage to the first loop filter;

[0046] The first loop filter performs integral filtering on the locking voltage to generate an integral filtered locking voltage, and sends the integral filtered locking voltage to the voltage control end of the multi-channel integrated coaxial dielectric oscillator;

[0047] Under the control of the locking voltage, the multi-channel integrated coaxial dielectric oscillator oscillates to generate two locking signals with the same frequency and amplitude. One locking signal is used as the output of the satellite-borne ultra-low phase noise broadband frequency hopping frequency source circuit, and the other locking signal is sent to the driving amplifier. The driving amplifier amplifies the locking signal power to the excitation level required by the balanced mixer and then sends it to the local oscillator port of the balanced mixer as the local oscillator signal required by the balanced mixer, and selects the channel through the control signal.

[0048] The second digital phase detector is used to perform phase detection on the crystal oscillation signal sent by the constant temperature crystal oscillator and the radio frequency signal sent by the coaxial dielectric oscillator, and send the output locking voltage to the second loop filter;

[0049] The second loop filter performs integral filtering on the locking voltage to generate an integral filtered locking voltage, and sends the integral filtered locking voltage to the voltage control end of the coaxial dielectric oscillator;

[0050] The coaxial dielectric oscillator oscillates the generated locking signal under the control of the locking voltage and feeds it into the balanced mixer and the second digital phase detector as a radio frequency signal;

[0051] The balanced mixer is used to mix the local oscillator signal output by the main loop and the radio frequency signal output by the auxiliary loop to obtain a difference frequency signal, and the difference frequency signal is amplified by an intermediate frequency amplifier and filtered by a low-pass filter to obtain an intermediate frequency signal, and the intermediate frequency signal is sent to the first digital phase detector;

[0052] The frequency control circuit is used to convert the discrete instructions input from the outside into the channel selection control signal of the multi-channel integrated coaxial dielectric oscillator of the main loop and the setting control level signal of the first digital phase detector, and send the channel selection control signal and the setting control level signal as control signals to the multi-channel integrated coaxial dielectric oscillator and the first digital phase detector respectively.

[0053] In the above technical solution, the constant temperature crystal oscillator generates two crystal oscillation signals with the same frequency and equal amplitude through oscillation, and sends the two crystal oscillation signals to the first digital phase detector and the second digital phase detector respectively; the first digital phase detector receives the control signal 1 from the frequency control circuit, and performs phase detection on the crystal oscillation signal sent by the constant temperature crystal oscillator and the intermediate frequency signal after amplification and filtering; the second digital phase detector is in a fixed setting mode, and is used to perform phase detection on the crystal oscillation signal sent by the constant temperature crystal oscillator and the radio frequency signal sent by the coaxial dielectric oscillator; the balanced mixer is used to mix the local oscillator signal output by the main loop and the radio frequency signal output by the auxiliary loop to obtain a difference frequency signal, and the difference frequency signal is amplified by the intermediate frequency amplifier and filtered by the low-pass filter to obtain an intermediate frequency signal, and the intermediate frequency signal is sent to the first digital phase detector;

[0054] Both the main ring and the auxiliary ring use coaxial dielectric oscillators, among which the dielectric oscillator of the main ring is multi-channel integrated and can switch between different channels through control signals. When switching, the power supply of the starting circuit of the dielectric oscillator of different channels is switched to meet the ultra-low phase noise requirement of the output. At the same time, by setting the frequency control circuit, the frequency hopping output frequency control within a certain frequency bandwidth is realized, which solves the technical problem in the prior art that the ultra-low phase noise index of the frequency source circuit and the broadband frequency hopping output cannot be met at the same time.

[0055] The first digital phase detector comprises an M frequency divider and a phase detector. The M frequency divider is connected to the frequency control circuit and the low-pass filter respectively, and the phase detector is connected to the constant temperature crystal oscillator and the first loop filter respectively.

[0056] The frequency control circuit includes an optical coupler, a decoder and a data selector connected in sequence;

[0057] Optocouplers are used to convert external input discrete instructions into photoelectric conversion;

[0058] The decoder is used to convert the discrete instructions after photoelectric conversion into parallel control signals. The parallel control signals are divided into two paths, one of which is used as the channel selection control signal (i.e., control signal 2) of the multi-channel integrated coaxial dielectric oscillator of the main loop, and the other is used as the input signal of the data selector;

[0059] The data selector is used to convert the parallel control signal output by the decoder into a setting control level signal of the M divider of the phase detector corresponding to the required frequency point. The setting control level signal is connected to the setting end of the M divider of the first phase detector of the main loop as a control signal.

[0060] In the above technical solution, by setting the flexible configuration of the decoder and the data selector, the frequency hopping output frequency control within a certain frequency bandwidth is realized. This control method does not require software configuration, and only discrete control execution is required to achieve frequency switching. By setting the optocoupler as an anti-interference functional device, the optocoupler can effectively prevent the control circuit malfunction caused by interference in the complex EMC environment inside the satellite.

[0061] The phase detection frequency of the second digital phase detector is an integer frequency point above 50 MHz.

[0062] In the above technical solution, the excellent in-band phase noise brought by the high phase detection frequency and the excellent far-end phase noise of the CRO are combined to obtain an excellent phase noise index in the entire band.

[0063] The multi-channel integrated coaxial dielectric oscillator includes four ports, wherein the first port and the second port are both control ports for receiving control instructions from a frequency control circuit, and then selecting different channels; the third port is a voltage-controlled voltage input port, for adjusting the output frequency of the fourth port according to the voltage-controlled voltage output by the first loop filter; the fourth port is a radio frequency output port, for outputting the final output frequency, and at the same time coupling a part of the output radio frequency signal through a coupler, and the output radio frequency signal is amplified by a driving amplifier as a local oscillator signal of a balanced mixer.

[0064] A method for using a satellite-borne ultra-low phase noise broadband frequency hopping frequency source circuit specifically comprises the following steps:

[0065] Step 1: When the loop of the main loop reaches the digital phase-locked loop lock, the locking voltage output by the first digital phase detector is sent to the first loop filter, the first loop filter performs integral filtering on the locking voltage to generate an integral filtered locking voltage, and the integral filtered locking voltage is sent to the voltage control end of the multi-channel integrated coaxial dielectric oscillator. Under the control of the locking voltage, the multi-channel integrated coaxial dielectric oscillator oscillates to generate two locking signals with the same frequency and equal amplitude. One locking signal is used as the output of the satellite-borne ultra-low phase noise broadband frequency hopping frequency source circuit, and the other locking signal is sent to the driving amplifier. After the driving amplifier amplifies the locking signal power to the excitation level required by the balanced mixer, it is sent to the local oscillator port of the balanced mixer as the local oscillator signal required by the balanced mixer;

[0066] Step 2: When the loop of the auxiliary loop reaches the digital phase-locked loop lock, the locking voltage output by the second digital phase detector is sent to the second loop filter, and the second loop filter performs integral filtering on the locking voltage to generate an integral filtered locking voltage and send it to the voltage control end of the coaxial dielectric oscillator. The coaxial dielectric oscillator oscillates under the control of the locking voltage to generate a locking signal, and feeds it into the balanced mixer and the second digital phase detector as a radio frequency signal;

[0067] Step three, the balanced mixer mixes the received local oscillator signal and the radio frequency signal to obtain a difference frequency signal, the difference frequency signal is amplified by the intermediate frequency amplifier and filtered by the low-pass filter to obtain an intermediate frequency signal, and the intermediate frequency signal is sent to the first digital phase detector.

[0068] The present invention provides a design example of a satellite-borne ultra-low phase noise broadband frequency hopping frequency source circuit, see Figure 2 , among which, Figure 1 The intermediate frequency amplifier and driver amplifier are used in Instead, crystal oscillators and dielectric oscillators are used Instead, the mixer uses replace.

[0069] The indicators achieved by the specific circuit are as follows:

[0070] Output frequency: 4.1GHz-4.2GHz

[0071] Frequency step: 5MHz

[0072] Reference frequency: 100MHz

[0073] Output power: 6dBm

[0074] Clutter suppression: ≥75dBc

[0075] Phase noise requirements:

[0076] ≤-70dBc / Hz@10Hz

[0077] ≤-85dBc / Hz@100Hz

[0078] ≤-95dBc / Hz@1kHz

[0079] ≤-105dBc / Hz@10kHz

[0080] ≤-115dBc / Hz@100kHz

[0081] ≤-135dBc / Hz@1MHz

[0082] The crystal oscillator generates a 100MHz reference signal through oscillation and divides it into two paths, one path is used as the reference signal of the first digital phase detector of the main loop, and the other path is used as the reference signal of the second digital phase detector of the auxiliary loop. According to the task requirements, a four-channel coaxial dielectric oscillator is selected as the outer loop output oscillator. The working frequency bands of the four channels are: channel 1: 4100-4125MHz, channel 2: 4125-4150MHz, channel 3: 4150-4175MHz, channel 4: 4175-4200MHz. The tuning sensitivity of each channel oscillator meets 4-5MHz / V, and the voltage control voltage range is 0-12V. The center frequency of the coaxial dielectric oscillator of the auxiliary loop is selected as 4GHz. In this way, the intermediate frequency entering the first digital phase detector is 100-200MHz. The task book requires a frequency step of 5MHz, so the reference divider R of the first digital phase detector in the circuit is fixed to "19". The modulus value of the decoder in the frequency control circuit is set to 4, so that the decoder output "00" selects channel 1 of the four-channel coaxial dielectric oscillator; "01" selects channel 2; "10" selects channel 3; "11" selects channel 4. The decoder output is also connected to the input of the data selector. According to the requirements of the above task book, the data selector is configured to meet the following logical correspondence. The specific correspondence is shown in Table 1. The control signal is further connected to the M frequency division setting of the first digital phase detector. The setting relationship determines the intermediate frequency, which determines the final output frequency. Taking the output of 4105MHz as an example, first the decoder in the frequency control circuit outputs "00" to select channel 1 of the main ring four-channel coaxial medium oscillator, ensuring that the main ring output frequency range is within 4100-4120MHz. Then, in the design, the output of the data selector is configured to be "010100", which is configured to the M frequency division setting of the ring phase detector. According to the calculation relationship between the output frequency of the first digital phase detector and the M frequency division setting, the required output frequency point can be obtained. The specific calculation method is as follows:

[0083] Fout=[(M+1)*Fref / (R+1)]+Fs;

[0084] Wherein, Fs represents the fixed frequency point of the output of the sub-loop; Fout represents the final output frequency; Fref represents the output frequency of the constant temperature crystal oscillator; R represents the R frequency division inside the first digital phase detector; M represents the M frequency division inside the first digital phase detector.

[0085] In the above calculation, Fs = 4000MHz, R = 19, Fout = 4105MHz, Fref = 100MHz, so after calculation, M = 20, and the corresponding binary configuration word is "010100". All the above control instructions are ultimately in the form of high and low levels.

[0086] In this embodiment, a constant temperature crystal oscillator is first used to generate a 100MHz crystal oscillation signal with high frequency stability, temperature stability and excellent phase noise, which solves the final output frequency stability and excellent phase noise characteristics in the 1Hz~100Hz frequency band; secondly, a four-channel coaxial dielectric oscillator is used as the final output oscillator. The module uses a micro-assembly integrated design and has excellent far-end phase noise characteristics. The remaining phase detectors, amplifiers, mixers, etc. have good radiation resistance characteristics. All circuits are reasonably laid out and designed. At the same time, the control circuit configuration can be adjusted according to the output frequency and the output frequency multiplication link can be added. It can provide ultra-low phase noise broadband frequency hopping local oscillator signals for satellite-borne broadband receivers and frequency converters. The circuit of the present invention does not require debugging and has high reliability. It can be well used in satellite-borne communications and radar systems.

[0087] Table 1

[0088]

Claims

1. A satellite-borne ultra-low phase noise broadband frequency hopping frequency source circuit, characterized in that: Used to realize ultra-low phase noise output and broadband frequency hopping output of a frequency source circuit, comprising a constant temperature crystal oscillator, wherein two ends of the constant temperature crystal oscillator are respectively connected to a main ring and an auxiliary ring; The main loop includes a first digital phase detector, a first loop filter, a multi-channel integrated coaxial dielectric oscillator, a driving amplifier, a balanced mixer, an intermediate frequency amplifier and a low-pass filter; the first digital phase detector is connected to the loop filter and the third input end of the multi-channel integrated coaxial dielectric oscillator in sequence; the first output end of the multi-channel integrated coaxial dielectric oscillator is connected to the driving amplifier, the balanced mixer, the intermediate frequency amplifier and the low-pass filter in sequence; the output end of the low-pass filter is connected to the first digital phase detector; the second output end of the multi-channel integrated coaxial dielectric oscillator serves as a signal output port; The auxiliary loop includes a second digital phase detector, a second loop filter and a coaxial dielectric oscillator which are connected in sequence; the first output end of the coaxial dielectric oscillator is connected to the balanced mixer, and the second output end of the coaxial dielectric oscillator is connected to the second digital phase detector; It also includes a frequency control circuit, wherein a first output terminal of the frequency control circuit is connected to the first digital phase detector, and a second output terminal and a third output terminal of the frequency control circuit are respectively connected to a first input terminal and a second input terminal of the multi-channel integrated coaxial dielectric oscillator; The constant temperature crystal oscillator generates two crystal oscillation signals with the same frequency and equal amplitude through oscillation, and sends the two crystal oscillation signals to the first digital phase detector and the second digital phase detector respectively; The first digital phase detector receives a control signal from the frequency control circuit, performs phase detection on a crystal oscillation signal sent by a constant temperature crystal oscillator and an intermediate frequency signal amplified by an intermediate frequency amplifier and filtered by a low-pass filter, and sends an output locking voltage to a first loop filter; The first loop filter performs integral filtering on the locking voltage to generate an integral filtered locking voltage, and sends the integral filtered locking voltage to the voltage control end of the multi-channel integrated coaxial dielectric oscillator; The multi-channel integrated coaxial dielectric oscillator oscillates and generates two channels of locking signals with the same frequency and amplitude under the control of the locking voltage. One channel of locking signal is used as the output of the satellite-borne ultra-low phase noise broadband frequency hopping frequency source circuit, and the other channel of locking signal is sent to the driving amplifier. The driving amplifier amplifies the locking signal power to the excitation level required by the balanced mixer and then sends it to the local oscillator port of the balanced mixer as the local oscillator signal required by the balanced mixer, and selects the channel through the control signal. The second digital phase detector is used to perform phase detection on the crystal oscillation signal sent by the constant temperature crystal oscillator and the radio frequency signal sent by the coaxial dielectric oscillator, and send the output locking voltage to the second loop filter; The second loop filter performs integral filtering on the locking voltage to generate an integral filtered locking voltage, and sends the integral filtered locking voltage to the voltage control end of the coaxial dielectric oscillator; The coaxial dielectric oscillator oscillates and generates a locking signal under the control of a locking voltage, and feeds the locking signal as a radio frequency signal into a balanced mixer and a second digital phase detector; The balanced mixer is used to mix the local oscillator signal output by the main loop and the radio frequency signal output by the auxiliary loop to obtain a difference frequency signal, and obtain an intermediate frequency signal after the difference frequency signal is amplified by an intermediate frequency amplifier and filtered by a low-pass filter, and the intermediate frequency signal is sent to the first digital phase detector; The frequency control circuit is used to convert the discrete instructions input from the outside into the channel selection control signal of the multi-channel integrated coaxial dielectric oscillator of the main loop and the setting control level signal of the first digital phase detector, and send the channel selection control signal and the setting control level signal as control signals to the multi-channel integrated coaxial dielectric oscillator and the first digital phase detector respectively.

2. The satellite-borne ultra-low phase noise broadband frequency hopping frequency source circuit as claimed in claim 1, characterized in that: The first digital phase detector includes an M frequency divider and a phase detector, the M frequency divider is connected to the frequency control circuit and the low-pass filter respectively, and the phase detector is connected to the constant temperature crystal oscillator and the first loop filter respectively.

3. The satellite-borne ultra-low phase noise broadband frequency hopping frequency source circuit as claimed in claim 1, characterized in that: The frequency control circuit includes an optical coupler, a decoder and a data selector connected in sequence; The optical coupler is used to perform photoelectric conversion on discrete instructions input from the outside; The decoder is used to convert the discrete instructions after photoelectric conversion into parallel control signals, and the parallel control signals are divided into two paths, one of which is used as the channel selection control signal of the multi-channel integrated coaxial dielectric oscillator of the main loop, and the other is used as the input signal of the data selector; The data selector is used to convert the parallel control signal output by the decoder into a setting control level signal of the M divider of the phase detector corresponding to the required frequency point. The setting control level signal is connected to the setting end of the M divider of the first phase detector of the main loop as a control signal.

4. The satellite-borne ultra-low phase noise broadband frequency hopping frequency source circuit as claimed in claim 1, characterized in that: The phase detection frequency of the second digital phase detector is an integer frequency point above 50 MHz.

5. The satellite-borne ultra-low phase noise broadband frequency hopping frequency source circuit as claimed in claim 1, characterized in that: The multi-channel integrated coaxial dielectric oscillator includes four ports, wherein the first port and the second port are both control ports, which are used to receive control instructions from the frequency control circuit, and then select different channels; the third port is a voltage-controlled voltage input port, which is used to adjust the output frequency of the fourth port according to the voltage-controlled voltage output by the first loop filter; the fourth port is a radio frequency output port, which is used to output the final output frequency, and at the same time couple a part of the output radio frequency signal through a coupler, and the output radio frequency signal is amplified by a driving amplifier as a local oscillator signal of a balanced mixer.

6. A method for using a satellite-borne ultra-low phase noise broadband frequency hopping frequency source circuit, characterized in that: Based on the satellite-borne ultra-low phase noise broadband frequency hopping frequency source circuit, the following steps are specifically included: Step 1: When the loop of the main loop reaches the digital phase-locked loop lock, the locking voltage output by the first digital phase detector is sent to the first loop filter, the first loop filter performs integral filtering on the locking voltage to generate an integral filtered locking voltage, and the integral filtered locking voltage is sent to the voltage control end of the multi-channel integrated coaxial dielectric oscillator. Under the control of the locking voltage, the multi-channel integrated coaxial dielectric oscillator oscillates to generate two locking signals with the same frequency and equal amplitude. One locking signal is used as the output of the satellite-borne ultra-low phase noise broadband frequency hopping frequency source circuit, and the other locking signal is sent to the driving amplifier. After the driving amplifier amplifies the locking signal power to the excitation level required by the balanced mixer, it is sent to the local oscillator port of the balanced mixer as the local oscillator signal required by the balanced mixer; Step 2: When the loop of the auxiliary loop reaches the digital phase-locked loop lock, the locking voltage output by the second digital phase detector is sent to the second loop filter, and the second loop filter performs integral filtering on the locking voltage to generate an integral filtered locking voltage and send it to the voltage control end of the coaxial dielectric oscillator. The coaxial dielectric oscillator oscillates under the control of the locking voltage to generate a locking signal, and feeds it into the balanced mixer and the second digital phase detector as a radio frequency signal; Step three, the balanced mixer mixes the received local oscillator signal and the radio frequency signal to obtain a difference frequency signal, the difference frequency signal is amplified by the intermediate frequency amplifier and filtered by the low-pass filter to obtain an intermediate frequency signal, and the intermediate frequency signal is sent to the first digital phase detector.

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