Phase-locked frequency synthesis method and device and electronic equipment

Abstract

The invention discloses a phase-locked frequency synthesis method and device and electronic equipment, and belongs to the technical field of electronics. The phase-locked frequency synthesis device comprises a PFD, a first filter, a VCO and a frequency mixing module, the output end of the PFD, the first filter and the input end of the VCO are connected in series, and the output end of the VCO, the frequency mixing module and the input end of the PFD are connected in series; the VCO is used for outputting a first frequency signal under the action of the driving voltage; the frequency mixing module is used for outputting a second frequency signal according to the first frequency signal; the second frequency signal is used for indicating whether the frequency of the first frequency signal is target frequency; the PFD is used for outputting a voltage adjusting signal when the second frequency signal indicates that the frequency of the first frequency signal is not the target frequency; the first filter is used for adjusting the driving voltage according to the voltage adjusting signal. The problem that the phase-locked frequency synthesis device cannot output the frequency signal of the target frequency is solved, and the phase-locked frequency synthesis device is used for synthesizing the frequency signal of the target frequency.

Description

Technical Field

[0001] The present application relates to the field of electronic technology, and in particular to a phase-locked frequency synthesis method and device, and electronic equipment. Background Art

[0002] A frequency synthesizer is a device that can generate a frequency signal. The frequency synthesizer can be used in electronic devices. The frequency signal generated by the frequency synthesizer can be processed by a signal processing device in the electronic device. The electronic device can be a quantum computing device, a measuring instrument, a communication device, a radar, etc.

[0003] There are many types of frequency synthesizers, such as direct frequency synthesizers, direct digital synthesizers (DDS), and phase-locked frequency synthesizers. Among them, the phase-locked frequency synthesizer can lock the frequency of the output frequency signal at a specified target frequency by locking the phase, so that the phase-locked frequency synthesizer can output a frequency signal with high stability.

[0004] However, the phase-locked frequency synthesizer may be mis-locked. At this time, the frequency of the frequency signal output by the phase-locked frequency synthesizer is locked at a non-target frequency, so that the phase-locked frequency synthesizer cannot output a frequency signal of the target frequency. Summary of the invention

[0005] The present application provides a phase-locked frequency synthesis method and device, and electronic equipment, which can solve the problem that the phase-locked frequency synthesis device cannot output a frequency signal of a target frequency. The technical solution is as follows:

[0006] In the first aspect, the present application provides a phase-locked frequency synthesis device, which includes: a PFD, a first filter, a VCO, and a mixing module. The output end of the PFD, the first filter, and the input end of the VCO are connected in series, and the output end of the VCO, the mixing module, and the input end of the PFD are connected in series. It can be seen that the mixing module is located in the feedback loop after the VCO.

[0007] The VCO is used to output a first frequency signal under the action of a driving voltage. The output end of the VCO is also the output end of the phase-locked frequency synthesizer, and the first frequency signal output by the VCO will output the phase-locked frequency synthesizer. The input end of the mixing module is connected to the output end of the VCO, and the mixing module can receive the first frequency signal output by the VCO. Afterwards, the mixing module is used to output a second frequency signal according to the received first frequency signal. The second frequency signal is used to indicate whether the frequency of the first frequency signal is the target frequency. For example, when the frequency of the first frequency signal is the target frequency, the power of the second frequency signal is within the target power range; when the frequency of the first frequency signal is not the target frequency, the power of the second frequency signal is outside the target power range. The target power range can be any power range, for example, the power within the target power range is greater than or equal to the power of the signal that the PFD can recognize, and the power outside the target power range is less than the power of the signal that the PFD can recognize.

[0008] The PFD is used to output a voltage adjustment signal to the first filter when the second frequency signal indicates that the frequency of the first frequency signal is not the target frequency. Accordingly, the PFD is also used to not output the voltage adjustment signal when the second frequency signal indicates that the frequency of the first frequency signal is the target frequency.

[0009] The first filter is also called a loop filter. The first filter is used to adjust the driving voltage of the VCO according to the provided voltage adjustment signal to adjust the frequency of the frequency signal (such as the above-mentioned first frequency signal) output by the VCO.

[0010] By repeating this cycle, the frequency of the frequency signal output by the VCO can be locked to the specified target frequency.

[0011] The second frequency signal is used to prevent the VCO from outputting a signal with a non-target frequency. The mixing module can output the second frequency signal according to whether the frequency of the first frequency signal is the target frequency, so that the PFD and the first filter adjust the driving voltage of the VCO when the second frequency signal indicates that the frequency of the first frequency signal is not the target frequency, and finally the frequency of the frequency signal output by the VCO is locked to the specified target frequency instead of the non-target frequency, thereby preventing the phase-locked frequency synthesis device from being mislocked.

[0012] The phase noise introduced when the device is connected in series between the output end of the VCO and the input end of the PFD is lower than the phase noise introduced when the device is connected to the input end of the VCO. Therefore, the phase noise introduced by the mixing module connected in series between the output end of the VCO and the input end of the PFD is lower than the phase noise introduced by the DAC connected to the input end of the VCO. Therefore, the phase noise introduced by the mixing module in the present application is low, so that the phase noise of the frequency signal output by the phase-locked frequency synthesis device is small. In addition, when the device is not connected to the input end of the VCO, the device will not pull the frequency offset of the frequency signal output by the VCO (or the probability of the frequency offset of the frequency signal output by the mixing module is low). Therefore, the probability of the phase-locked frequency synthesis device losing lock can be reduced. In addition, the phase-locked frequency synthesis device provided in the embodiment of the present application does not use multiple feedback loops, so the complexity of the phase-locked frequency synthesis device is low, the cost is low, the area is small, the power consumption is also small, and more phase noise will not be introduced due to multiple feedback loops.

[0013] The above-mentioned frequency mixing module includes a mixer and other devices. The frequency mixing module can be implemented in various ways, and two of the implementations will be used as examples for explanation. It is understandable that the implementation of the frequency mixing module can also be different from the following two implementations.

[0014] (1) For example, the mixing module includes: a first power divider, a first mixer, a second mixer, a first local oscillator signal source, a 90-degree power divider, a first phase shifter, a second phase shifter, and a combiner. The output end of the VCO, the first power divider, the first mixer, the first phase shifter, the combiner, and the input end of the PFD are connected in series; the output end of the VCO, the first power divider, the second mixer, the second phase shifter, the combiner, and the input end of the PFD are connected in series; the first local oscillator signal source, the 90-degree power divider, and the first mixer are connected in series, and the first local oscillator signal source, the 90-degree power divider, and the second mixer are connected in series;

[0015] The first phase shifter is used to change the phase of the passing signal to a first phase, and the second phase shifter is used to change the phase of the passing signal to a second phase, and the absolute value of the difference between the first phase and the second phase is 90 degrees; the first local oscillator signal source based on which the mixing module outputs the second frequency signal is used to provide a first initial local oscillator signal, and the initial local oscillator signal in the present application can be generated by a dielectric crystal oscillator (such as an oscillator) or the like.

[0016] The 90-degree power divider may be a proportional power divider or may not be a proportional power divider, which is not limited in this application. The first power divider may be a proportional power divider or may not be a proportional power divider, which is not limited in this application. It can be seen that at least one power divider in the mixing module is a proportional power divider, or all power dividers in the mixing module are not proportional power dividers.

[0017] (2) For example, the mixing module includes: a first power divider, a first mixer, a second mixer, a first local oscillator signal source, a 90-degree power divider, a first phase shifter, a second phase shifter, a third mixer, a fourth mixer, a second local oscillator signal source, a second power divider and a combiner; the output end of the VCO, the first power divider, the first mixer, the third mixer, the combiner and the input end of the PFD are connected in series; the output end of the VCO, the first power divider, the second mixer, the fourth mixer, the combiner and the input end of the PFD are connected in series ; The first local oscillator signal source, the 90-degree power divider and the first mixer are connected in series, the first local oscillator signal source, the 90-degree power divider and the second mixer are connected in series; the second local oscillator signal source, the second power divider, the first phase shifter and the third mixer are connected in series, the second local oscillator signal source, the second power divider, the second phase shifter and the fourth mixer are connected in series; the first phase shifter is used to change the phase of the passing signal by a first phase, the second phase shifter is used to change the phase of the passing signal by a second phase, and the absolute value of the difference between the first phase and the second phase is 90 degrees.

[0018] The 90-degree power divider may be a proportional power divider or may not be a proportional power divider, and this application does not limit this. The two signals obtained by the proportional power divider by dividing the power of one signal have the same power. The first power divider may be a proportional power divider or may not be a proportional power divider, and this application does not limit this. The second power divider 4053 may be a proportional power divider or may not be a proportional power divider. It can be seen that at least one power divider in the mixing module is a proportional power divider, or all power dividers in the mixing module are not proportional power dividers. This application does not limit this.

[0019] In the above two possible implementations of the frequency mixing module, the first phase and the second phase can be set according to the target frequency selected as needed. Optionally, the frequency mixing module also includes: a controller, the controller is connected to the first phase shifter and the second phase shifter; the controller is used to control the first phase shifter to adjust the first phase, and control the second phase shifter to adjust the second phase. In this case, the first phase shifter and the second phase shifter are both adjustable phase shifters. It can be seen that the present application can also set the first phase and the second phase through the controller.

[0020] Optionally, the input ends of the combiner and the PFD in the mixing module may be indirectly connected through other devices. In this case, the signal output by the combiner is not a second frequency signal, and the signal output by the combiner becomes a second frequency signal after passing through these other devices and is transmitted to the PFD.

[0021] Optionally, these other devices may include at least one of a frequency divider and a second filter, the frequency division coefficient of the frequency divider may be greater than 1 or less than 1, and the frequency division coefficient may be an integer or a decimal. The frequency divider is used to divide the frequency of the passing signal, and the second filter is used to filter the passing signal. In the case where the other device includes a frequency divider and a second filter, the input ends of the combiner, the second filter, the frequency divider and the PFD may be connected in series, or the input ends of the combiner, the frequency divider, the second filter and the PFD may be connected in series.

[0022] When these other devices include a frequency divider, the coefficient of the frequency divider is positively correlated with the frequency tuning step of the signal output by the phase-locked frequency synthesizer. Therefore, when the coefficient of the frequency divider is small, the frequency tuning step (such as sub-hertz tuning step) of the signal output by the phase-locked frequency synthesizer is small, which is conducive to achieving accurate tuning of the frequency of the signal output by the phase-locked frequency synthesizer. Since the mixing module also has the function of frequency conversion, the frequency division coefficient of the frequency divider can be set smaller, thereby avoiding the large phase noise introduced by setting the frequency division coefficient of the frequency divider larger.

[0023] The second filter can be used to filter out the spurious signals and interference signals generated by the above-mentioned mixing part, and the second filter can be a low-pass filter.

[0024] In a second aspect, the present application provides an electronic device comprising: a signal processing device, and a phase-locked frequency synthesis device as described in any design of the first aspect, wherein the signal processing device is connected to the VCO in the phase-locked frequency synthesis device and is used to process a first frequency signal output by the VCO.

[0025] In a third aspect, the present application provides a phase-locked frequency synthesis method, which is performed by a phase-locked frequency synthesis device described in any design of the first aspect. The method includes: after the VCO outputs a first frequency signal under the action of a driving voltage, the mixing module outputs a second frequency signal according to the first frequency signal; the second frequency signal is used to indicate whether the frequency of the first frequency signal is a target frequency; when the second frequency signal indicates that the frequency of the first frequency signal is not the target frequency, the PFD outputs a voltage adjustment signal, so that the first filter adjusts the driving voltage according to the voltage adjustment signal.

[0026] Optionally, when the frequency of the first frequency signal is the target frequency, the power of the second frequency signal is within the target power range; when the frequency of the first frequency signal is not the target frequency, the power of the second frequency signal is outside the target power range.

[0027] Optionally, the power within the target power range is greater than or equal to the power of the signal that the PFD can identify, and the power outside the target power range is less than the power of the signal that the PFD can identify.

[0028] The above-mentioned frequency mixing module includes a mixer and other devices. The frequency mixing module can be implemented in various ways, and two of the implementations will be used as examples for explanation. It is understandable that the implementation of the frequency mixing module can also be different from the following two implementations.

[0029] (1) By way of example, the mixing module includes: a first power divider, a first mixer, a second mixer, a first local oscillator signal source, a 90-degree power divider, a first phase shifter, a second phase shifter and a combiner; the output end of the VCO, the first power divider, the first mixer, the first phase shifter, the combiner and the input end of the PFD are connected in series; the output end of the VCO, the first power divider, the second mixer, the second phase shifter, the combiner and the input end of the PFD are connected in series; the first local oscillator signal source, the 90-degree power divider and the first mixer are connected in series, and the first local oscillator signal source, the 90-degree power divider and the second mixer are connected in series; the first local oscillator signal source is used to provide a first initial local oscillator signal.

[0030] In this case, when the mixing module outputs the second frequency signal according to the first frequency signal, the 90-degree power divider transmits the first power division local oscillator signal to the first mixer based on the first initial local oscillator signal, and transmits the second power division local oscillator signal to the second mixer; the first power divider transmits the first frequency power division signal to the first mixer based on the first frequency signal, and transmits the second frequency power division signal to the second mixer; the first mixer mixes the first frequency power division signal with the first power division local oscillator signal and outputs the result; the second mixer mixes the second frequency power division signal with the second power division local oscillator signal and outputs the result; the first phase shifter changes the phase of the signal from the first mixer by a first phase and outputs the result; the second phase shifter changes the phase of the signal from the second mixer by a second phase and outputs the result; the absolute value of the difference between the first phase and the second phase is 90 degrees; the combiner combines the signal from the first phase shifter with the signal from the second phase shifter and outputs the result.

[0031] (2) For example, the mixing module includes: a first power divider, a first mixer, a second mixer, a first local oscillator signal source, a 90-degree power divider, a first phase shifter, a second phase shifter, a third mixer, a fourth mixer, a second local oscillator signal source, a second power divider and a combiner; the output end of the VCO, the first power divider, the first mixer, the third mixer, the combiner and the input end of the PFD are connected in series; the output end of the VCO, the first power divider, the second mixer, the fourth mixer, the combiner and the input end of the PFD are connected in series; the first local oscillator signal source, the 90-degree power divider and the first mixer are connected in series, and the first local oscillator signal source, the 90-degree power divider and the second mixer are connected in series; the second local oscillator signal source, the second power divider, the first phase shifter and the third mixer are connected in series, and the second local oscillator signal source, the second power divider, the second phase shifter and the fourth mixer are connected in series; the first local oscillator signal source is used to provide a first initial local oscillator signal; the second local oscillator signal source is used to provide a second initial local oscillator signal;

[0032] In this case, when the mixing module outputs the second frequency signal according to the first frequency signal, the 90-degree power divider transmits the first power division local oscillator signal to the first mixer based on the first initial local oscillator signal, and transmits the second power division local oscillator signal to the second mixer; the first power divider transmits the first frequency power division signal to the first mixer based on the first frequency signal, and transmits the second frequency power division signal to the second mixer; the first mixer mixes the first frequency power division signal with the first power division local oscillator signal and outputs the signal; the second mixer mixes the second frequency power division signal with the second power division local oscillator signal and outputs the signal; the second power divider is based on the second initial local oscillator signal, The third power division local oscillator signal is transmitted to the first phase shifter, and the fourth power division local oscillator signal is transmitted to the second phase shifter; the first phase shifter changes the phase of the third power division local oscillator signal by a first phase and outputs the signal; the second phase shifter changes the phase of the fourth power division local oscillator signal by a second phase and outputs the signal; the absolute value of the difference between the first phase and the second phase is 90 degrees; the third mixer mixes the signal from the first mixer with the signal from the first phase shifter and outputs the signal; the fourth mixer mixes the signal from the second mixer with the signal from the second phase shifter and outputs the signal; the combiner combines the signal from the third mixer with the signal from the fourth mixer and outputs the signal.

[0033] Optionally, the mixing module also includes: a controller connected to the first phase shifter and the second phase shifter; when the mixing module outputs the second frequency signal according to the first frequency signal, the controller controls the first phase shifter to adjust the first phase, and controls the second phase shifter to adjust the second phase.

[0034] Optionally, the frequency mixing module further includes: a frequency divider, which is connected in series between the combiner and the input port of the PFD; when the frequency mixing module outputs the second frequency signal according to the first frequency signal, the frequency divider divides the signal from the combiner and outputs it.

[0035] Optionally, the frequency mixing module further includes: a second filter, which is connected in series between the combiner and the input port of the PFD; when the frequency mixing module outputs the second frequency signal according to the first frequency signal, the second filter filters the signal from the combiner and then outputs it.

[0036] For the effects of the second and third aspects mentioned above, please refer to the effects of the corresponding designs in the first aspect, and this application will not go into details here. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application;

[0038] Figure 2 A schematic diagram of the structure of a phase-locked frequency synthesis device provided in an embodiment of the present application;

[0039] Figure 3A schematic diagram of the structure of another phase-locked frequency synthesis device provided in an embodiment of the present application;

[0040] Figure 4 A schematic diagram of the structure of another phase-locked frequency synthesis device provided in an embodiment of the present application;

[0041] Figure 5 A schematic diagram of the structure of a frequency mixing module provided in an embodiment of the present application;

[0042] Figure 6 A schematic diagram of the structure of another frequency mixing module provided in an embodiment of the present application;

[0043] Figure 7 A schematic diagram of the structure of another phase-locked frequency synthesis device provided in an embodiment of the present application;

[0044] Figure 8 A flow chart of a phase-locked frequency synthesis method provided in an embodiment of the present application;

[0045] Fig. 9 A flowchart of a method for outputting a second frequency signal according to a first frequency signal provided in an embodiment of the present application;

[0046] Fig.10 A flowchart of another method for outputting a second frequency signal according to a first frequency signal provided in an embodiment of the present application. DETAILED DESCRIPTION

[0047] In order to make the principles and technical solutions of the present application clearer, the implementation methods of the present application will be further described in detail below in conjunction with the accompanying drawings.

[0048] The present application provides an electronic device, which may be a quantum computing device (such as a superconducting quantum computing device), a measuring instrument, a communication device (such as a mobile communication device), a radar, etc. Figure 1 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application is shown in FIG. Figure 1 As shown, the electronic device includes: a frequency synthesis device (such as Figure 1 The phase-locked frequency synthesizer 01 and the signal processing device 02 are connected to the output end of the frequency synthesizer, and the signal processing device 02 is used to process the frequency signal output by the frequency synthesizer. For example, when the electronic device is a quantum computing device, the signal processing device 02 can perform quantum computing based on the frequency signal; when the electronic device is a measuring instrument, the signal processing device can measure parameters based on the frequency signal; when the electronic device is a communication device, the signal processing device can communicate based on the frequency signal.

[0049] Frequency synthesizers are also called frequency synthesizers and frequency signal output devices. Phase-locked frequency synthesizers can output high-precision and high-stability frequency signals. Phase-locked frequency synthesizers usually use a phase-locked loop to tune the frequency output by the phase-locked frequency synthesizer, and finally lock the frequency of the frequency signal output by the phase-locked frequency synthesizer at a specified target frequency.

[0050] For example, Figure 2 A schematic diagram of the structure of a phase-locked frequency synthesis device provided in an embodiment of the present application is shown in FIG. Figure 2 As shown, the phase-locked frequency synthesis device includes: a phase frequency detector (PFD) 011, a first filter 012 (also called a loop filter), a voltage-controlled oscillator (VCO) 013, and a frequency divider 014. The PFD 011, the first filter 012, the VCO 013, and the frequency divider 014 are connected in series, and the frequency divider 014 is also connected to the PFD 011. The output end of the VCO 013 is the output end of the phase-locked frequency synthesis device.

[0051] VCO 013 is used to output a frequency signal under the action of a driving voltage. The frequency divider 014 can obtain the frequency signal, and after down-converting the frequency signal by frequency division, transmit it to PFD 011. PFD 011 can determine the phase difference between a reference signal (such as a reference clock signal) and a signal from the frequency divider 014. When the phase difference is a specified phase difference, PFD011 can determine that the frequency of the frequency signal currently output by VCO 013 is the target frequency; when the phase difference is not a specified phase difference, PFD 011 can output a voltage adjustment signal to the first filter 012 according to the phase difference. The first filter 012 can adjust the driving voltage of VCO 013 according to the voltage adjustment signal to adjust the frequency of the frequency signal output by VCO 013. In this way, the phase difference between the signal transmitted from the frequency divider 014 to PFD 011 and the reference signal can be locked at the specified phase difference, thereby achieving the frequency of the frequency signal output by VCO 013 being locked at the specified target frequency fo=fr*N. Wherein, fr represents the frequency of the reference signal, and N represents the frequency division coefficient of the frequency divider, which can be an integer greater than 1 or a decimal.

[0052] Furthermore, when the frequency synthesizer is used in certain electronic devices (such as superconducting quantum computing devices), the frequency synthesizer needs to have the characteristics of large bandwidth and small step tuning. The bandwidth of the frequency synthesizer is positively correlated with the phase noise of the frequency signal output by the frequency synthesizer, and the tuning step of the frequency synthesizer is negatively correlated with the phase noise of the frequency signal output by the frequency synthesizer. In the case where the frequency synthesizer needs to have large bandwidth and small step tuning characteristics, the phase noise of the frequency signal output by the frequency synthesizer is usually high, making the performance of the frequency signal poor. Therefore, it is necessary to reduce the phase noise of the frequency signal output by the frequency synthesizer.

[0053] In a phase-locked frequency synthesizer, the phase noise introduced by the frequency divider is usually large. Therefore, in order to reduce the phase noise of the frequency signal output by the frequency synthesizer, the frequency divider can be replaced by a mixer, and the mixer down-converts the frequency signal output by the VCO and transmits it to the PFD. Since the phase noise introduced by the mixer is lower than the phase noise introduced by the frequency divider, the phase noise of the frequency signal output by the frequency synthesizer can be reduced. In addition, the phase noise introduced by one mixer is greater than the phase noise introduced by multiple mixers connected in series. Therefore, the frequency divider can also be replaced by multiple mixers connected in series (such as 015). Figure 3 shown).

[0054] However, the mixer has a double-sideband, so that the mixer will alternately output two mixing results. Therefore, the phase-locked frequency synthesis device may lock the phase difference between one mixing result and the reference signal at a specified phase difference, thereby locking the frequency of the frequency signal output by VCO013 at one frequency; the phase frequency synthesis device may also lock the phase difference between another mixing result and the reference signal at a specified phase difference, thereby locking the frequency of the frequency signal output by VCO 013 at another frequency. It can be seen that the frequency of the frequency signal output by VCO 013 will be locked at any one of the two frequencies, which include the target frequency (specified frequency) and the non-target frequency (frequency different from the target frequency), and the either frequency may be the target frequency or the non-target frequency. When the frequency of the frequency signal output by VCO 013 is locked at a non-target frequency, the phase-locked frequency synthesis device is mislocked. At this time, the phase-locked frequency synthesis device cannot output a frequency signal of the target frequency.

[0055] Therefore, in order to reduce the probability of mislocking of the phase-locked frequency synthesis device, it is necessary to provide a component for reducing the probability of mislocking in the phase-locked frequency synthesis device.

[0056] For example, Figure 3As shown, in order to reduce the probability of the phase-locked frequency synthesis device being mislocked, a digital signal source 016 and a digital-to-analog converter (DAC) 017 can be provided in the phase-locked frequency synthesis device, and the input ends of the digital signal source 016, DAC 017, and VCO 013 are connected in series. Optionally, the phase-locked frequency synthesis device 01 further includes an operational amplifier (attached Figure 3 DAC 017 may be connected to the input terminal of VCO 013 via the operational amplifier.

[0057] The digital signal source 016 is used to provide a digital signal to the DAC 017, and the DAC 017 is used to convert the digital signal into an analog signal and transmit it to the VCO 013. The analog signal is used to set the driving voltage of the VCO 013 so that the frequency of the frequency signal output by the VCO 013 is close to the target frequency, but not equal to the target frequency. After that, under the action of the PFD 011, the first filter 012, and the mixer 015, the driving voltage is tuned. When the frequency of the frequency signal output by the VCO 013 is close to the target frequency, the probability of tuning the frequency of the frequency signal output by the VCO 013 to the target frequency is high, while the probability of tuning the frequency of the frequency signal output by the VCO 013 to a non-target frequency is low. Therefore, under the action of the PFD 011, the first filter 012, and the mixer 015, the driving voltage is tuned, and the frequency of the frequency signal output by the VCO 013 can be adjusted to the target frequency with a high probability, thereby reducing the probability of the phase-locked frequency synthesis device being mislocked.

[0058] However, the connection of DAC 017 to the input of VCO will introduce phase noise, which will increase the phase noise of the frequency signal output by the phase-locked frequency synthesizer. In addition, the connection of DAC 017 to the input of VCO 013 will pull the frequency deviation of the frequency signal output by VCO 013, which may cause the phase-locked frequency synthesizer to be unable to lock the frequency of the output frequency signal to the target frequency, thereby causing the phase-locked frequency synthesizer to lose lock. In particular, VCOs used to output high-frequency and broadband frequency signals are particularly sensitive to the devices connected to the input of the VCO, and are more easily affected, and are more likely to experience increased phase noise and loss of lock.

[0059] The embodiment of the present application provides a phase-locked frequency synthesis device, which uses a mixing module therein to output a second frequency signal based on a first frequency signal to instruct the PFD and the first filter to adjust the driving voltage of the VCO when the VCO outputs a signal of a non-target frequency, and adjust the frequency output by the VCO, thereby avoiding the phase-locked frequency synthesis device from being mislocked. In addition, the mixing module is connected in series between the output end of the VCO and the input end of the PFD. Since the phase noise introduced by the mixing module connected in series between the output end of the VCO and the input end of the PFD is lower than the phase noise introduced by the DAC connected to the input end of the VCO, the phase noise introduced by the mixing module in the present application is lower, so that the phase noise of the frequency signal output by the phase-locked frequency synthesis device is smaller. Since the mixing module is not connected to the input end of the VCO, the mixing module does not pull the frequency offset of the frequency signal output by the VCO (or the probability of the mixing module pulling the frequency offset of the frequency signal output by the VCO is low), so the probability of the phase-locked frequency synthesis device losing lock can be reduced.

[0060] For example, Figure 4 A schematic diagram of the structure of a phase-locked frequency synthesis device provided in an embodiment of the present application is shown in FIG. Figure 4 As shown, the phase-locked frequency synthesis device 01 includes: PFD 401, a first filter 402, a VCO 403, and a mixing module 404. The output end of PFD 401, the first filter 402, and the input end of VCO 403 are connected in series, and the output end of VCO 403, the mixing module 404, and the input end of PFD 401 are connected in series. It can be seen that the mixing module 404 is located on the feedback loop (also called phase locked loop (PLL)) after VCO 403.

[0061] VCO 403 is used to output a first frequency signal under the action of a driving voltage. For example, the frequency of the first frequency signal fvco=f0+K0*Vc, where f0 is a constant, K0 is a voltage control sensitivity, and Vc is a driving voltage. The output end of VCO 403 is also the output end of the phase-locked frequency synthesizer, and the first frequency signal output by VCO 403 will output the phase-locked frequency synthesizer.

[0062] The input end of the frequency mixing module 404 is connected to the output end of the VCO 403. For example, the frequency mixing module 404 is coupled or directly connected (contacted) to the output end of the VCO 403. The frequency mixing module 404 can receive the first frequency signal output by the VCO 403. Thereafter, the frequency mixing module 404 can be used to output a second frequency signal according to the received first frequency signal.

[0063] The second frequency signal is used to indicate whether the frequency of the first frequency signal is the target frequency. For example, when the frequency of the first frequency signal is the target frequency, the power of the second frequency signal is within the target power range; when the frequency of the first frequency signal is not the target frequency, the power of the second frequency signal is outside the target power range. The target power range can be any power range, for example, the power within the target power range is greater than or equal to the power of the signal that the PFD can recognize, and the power outside the target power range is less than the power of the signal that the PFD can recognize.

[0064] Of course, the power within the target power range and the power outside the target power range may be greater than or equal to the power of the signal that the PFD can identify, or less than the power of the signal that the PFD can identify. The second frequency signal may also indicate whether the frequency of the first frequency signal is the target frequency without determining whether the power is within the target power range. For example, the second frequency signal may indicate whether the frequency of the first frequency signal is the target frequency through parameters such as frequency and phase.

[0065] The PFD 401 is used to output a voltage adjustment signal (voltage signal or current signal) to the first filter 012 when the second frequency signal indicates that the frequency of the first frequency signal is not the target frequency. The PFD 401 can be an analog phase detector (such as a multiplier, etc.) or a digital phase detector (such as a gate phase detector, etc.). Accordingly, the PFD 401 is also used to not output the voltage adjustment signal when the second frequency signal indicates that the frequency of the first frequency signal is the target frequency.

[0066] For example, when the power within the target power range is greater than or equal to the power of the signal that the PFD can recognize, and the power outside the target power range is less than the power of the signal that the PFD can recognize, if the PFD cannot recognize the signal from the mixing module 404, it is considered that the power of the signal is outside the target power range, and the second frequency signal indicates that the frequency of the first frequency signal is not the target frequency; if the PFD can recognize the signal from the mixing module 404, it is considered that the power of the signal is within the target power range, and the second frequency signal indicates that the frequency of the first frequency signal is the target frequency.

[0067] When it is determined that the second frequency signal indicates that the frequency of the first frequency signal is not the target frequency, the PFD 401 can determine a phase difference based on the second frequency signal and a reference signal (which can be a signal generated by the PFD or a signal provided to the PFD by a reference signal source), and output a voltage adjustment signal based on the phase difference. The phase difference can be a phase difference between the second frequency signal and the reference signal, or a phase difference between other preset signals and the reference signal. For example, assuming that the PFD 401 cannot identify the second frequency signal when the second frequency signal indicates that the frequency of the first frequency signal is not the target frequency, the phase difference can be a phase difference between other preset signals and the reference signal. Assuming that the PFD 401 can identify the second frequency signal when the second frequency signal indicates that the frequency of the first frequency signal is not the target frequency, the phase difference can be a phase difference between the second frequency signal and the reference signal.

[0068] In addition, when the second frequency signal indicates that the frequency of the first frequency signal is the target frequency, the PFD 401 may determine a phase difference between the second frequency signal and the reference frequency signal, and the phase difference may be a specified phase difference.

[0069] The first filter 402 is also called a loop filter. The first filter 402 is used to adjust the driving voltage of the VCO 403 according to the voltage adjustment signal provided by the PFD to adjust the frequency of the frequency signal (such as the above-mentioned first frequency signal) output by the VCO 403. For example, the first filter 402 is used to filter out high-frequency noise and interference from the voltage adjustment signal provided by the PFD, and transmit the signal obtained after filtering to the VCO 403 to use the signal to adjust the driving voltage of the VCO 403. The first filter 402 can be a passive filter or an active filter. When the first filter 402 is an active filter, it is beneficial to tune the frequency of the signal output by the VCO to a large extent to provide a certain gain. At the same time, the first filter 402 also has the functions of smoothing the PFD output, ensuring the stability of the phase-locked frequency synthesizer, and improving the tracking performance and noise characteristics of the phase-locked frequency synthesizer.

[0070] In this way, the frequency signal output by the VCO 403 can be locked to a specified target frequency. The target frequency here can be any frequency, such as a microwave frequency, a millimeter wave frequency, etc.

[0071] Here, the frequency mixing module 404 includes a mixer and other devices, which are not limited in this application. Usually, the frequency of the signal output by the VCO is higher, while the frequency of the signal processed by the PFD is lower, so the frequency of the second frequency signal output by the frequency mixing module 404 is lower than the frequency of the first frequency signal. Of course, the frequency of the second frequency signal output by the frequency mixing module 404 may also be greater than or equal to the frequency of the first frequency signal, which is not limited in this embodiment of the application.

[0072] The second frequency signal is used to prevent the VCO 403 from outputting a signal of a non-target frequency. The frequency mixing module 404 can output the second frequency signal according to whether the frequency of the first frequency signal is the target frequency, so that the PFD 401 and the first filter 402 adjust the driving voltage of the VCO 403 when the second frequency signal indicates that the frequency of the first frequency signal is not the target frequency, and finally the frequency of the frequency signal output by the VCO 403 is locked to the specified target frequency instead of being locked to the non-target frequency, thereby preventing the phase-locked frequency synthesis device from being mislocked.

[0073] The phase noise introduced when the device is connected in series between the output end of VCO 403 and the input end of PFD 401 is lower than the phase noise introduced when the device is connected to the input end of VCO 403. Therefore, the phase noise introduced by the mixing module 404 connected in series between the output end of VCO 403 and the input end of PFD 401 is lower than the phase noise introduced by the DAC connected to the input end of VCO 403. Therefore, the phase noise introduced by the mixing module 404 in the present application is low, so that the phase noise of the frequency signal output by the phase-locked frequency synthesizer is small. In addition, when the device is not connected to the input end of VCO 403, the device will not pull the frequency offset of the frequency signal output by VCO 403 (or the probability of the frequency offset of the frequency signal output by the mixing module pulling the VCO is low). Therefore, the probability of the phase-locked frequency synthesizer losing lock can be reduced. Furthermore, the phase-locked frequency synthesis device provided in the embodiment of the present application does not use multiple feedback loops. Therefore, the phase-locked frequency synthesis device has lower complexity, lower cost, smaller area, lower power consumption, and will not introduce more phase noise due to multiple feedback loops.

[0074] The frequency mixing module 404 includes a mixer and other devices. The frequency mixing module 404 can be implemented in various ways, and two of the implementations will be used as examples for explanation. It is understandable that the implementation of the frequency mixing module 404 can also be different from the following two implementations.

[0075] (1) For example, Figure 5 A structural diagram of a frequency mixing module 404 provided in an embodiment of the present application is shown in FIG. Figure 5 As shown, the mixing module 404 includes: a first power divider 4041, a first mixer 4042, a second mixer 4043, a first local oscillator signal source 4044, a 90-degree power divider 4045, a first phase shifter 4046, a second phase shifter 4047 and a combiner 4048.

[0076] The output end of VCO 403, the first power divider 4041, the first mixer 4042, the first phase shifter 4046, the combiner 4048 and the input end of PFD 401 are connected in series; the output end of VCO 403, the first power divider 4041, the second mixer 4043, the second phase shifter 4047, the combiner 4048 and the input end of PFD 401 are connected in series; the first local oscillator signal source 4044, the 90-degree power divider 4045 and the first mixer 4042 are connected in series, and the first local oscillator signal source 4044, the 90-degree power divider 4045 and the second mixer 4043 are connected in series.

[0077] The first phase shifter 4046 is used to change the phase of the passing signal to a first phase, and the second phase shifter 4047 is used to change the phase of the passing signal to a second phase, and the absolute value of the difference between the first phase and the second phase is 90 degrees; the first local oscillator signal source based on which the mixing module 404 outputs the second frequency signal is used to provide a first initial local oscillator signal, and the initial local oscillator signal in the present application can be generated by a dielectric crystal oscillator (such as an oscillator) or the like.

[0078] For example, when the mixing module 404 outputs the second frequency signal according to the first frequency signal, the 90-degree power divider 4045 is used to transmit the first power-divided local oscillator signal to the first mixer 4042 based on the first initial local oscillator signal, and transmit the second power-divided local oscillator signal to the second mixer 4043. The 90-degree power divider 4045 can divide the first initial local oscillator signal into two signals, and adjust the phase of at least one of the two signals to obtain the first power-divided local oscillator signal and the second power-divided local oscillator signal. In addition, the phases of the first power-divided local oscillator signal and the second power-divided local oscillator signal differ by 90 degrees. The 90-degree power divider 4045 may be a proportional power divider or may not be a proportional power divider, which is not limited in the present application. The two signals obtained by the proportional power divider dividing a signal have the same power. Therefore, when the 90-degree power divider 4045 is a proportional power divider, the power of the first power-divided local oscillator signal and the second power-divided local oscillator signal are the same.

[0079] When the mixing module 404 outputs the second frequency signal according to the first frequency signal, the first power divider 4041 is used to transmit the first frequency power divided signal to the first mixer 4042 based on the first frequency signal from the VCO 403, and transmit the second frequency power divided signal to the second mixer 4043. It can be seen that after the first power divider 4041 divides the first frequency signal, it obtains the first frequency power divided signal and the second frequency power divided signal, and transmits the first frequency power divided signal to the first mixer 4042, and transmits the second frequency power divided signal to the second mixer 4043. The first power divider 4041 can be an equal-proportional power divider, or it can be a non-equal-proportional power divider, which is not limited in this application. It can be seen that at least one power divider in the mixing module 404 is an equal-proportional power divider, or all power dividers in the mixing module 404 are not equal-proportional power dividers. When the first power divider 4041 is an equal-proportional power divider, the power of the first frequency power divided signal and the second frequency power divided signal is the same.

[0080] The first mixer 4042 mixes the first frequency power division signal from the first power divider 4041 with the first power division local oscillator signal from the 90-degree power divider 4045 and outputs the mixed signal to the first phase shifter 4046. The second mixer 4043 mixes the second frequency power division signal from the first power divider 4041 with the second power division local oscillator signal from the 90-degree power divider 4045 and outputs the mixed signal to the second phase shifter 4047. Since the phase difference between the first power division local oscillator signal and the second power division local oscillator signal is 90 degrees, the first power division local oscillator signal and the second power division local oscillator signal are orthogonal. The first frequency power division signal and the second frequency power division signal are both obtained by power division of the first frequency signal. Therefore, the first frequency power division signal and the second frequency power division signal have the same phase. The signal obtained by mixing the first frequency power division signal with the first power division local oscillator signal (which can be called an I signal) is orthogonal to the signal obtained by mixing the second frequency power division signal with the second power division local oscillator signal (which can be called a Q signal).

[0081] Next, the first phase shifter 4046 can change the phase of the I signal from the first mixer 4042 by a first phase and output it to the combiner 4048, and the second phase shifter 4047 changes the phase of the Q signal from the second mixer 4043 by a second phase and output it to the combiner 4048. The combiner 4048 combines the signal from the first phase shifter 4046 with the signal from the second phase shifter 4047 to obtain a second frequency signal and output it to the PFD 401.

[0082] The absolute value of the difference between the first phase and the second phase is 90 degrees, for example, the difference between the first phase and the second phase is 90 degrees, or the difference between the first phase and the second phase is -90 degrees. By setting the absolute value of the difference between the first phase and the second phase to 90 degrees, the signal obtained by the I signal after changing the first phase and the signal obtained by the Q signal after changing the second phase are combined in the combiner 4048, and the above-mentioned second frequency signal can be obtained. When the frequency of the first frequency signal is the target frequency, the signal obtained by the I signal after changing the first phase and the signal obtained by the Q signal after changing the second phase will not cancel each other out in power when combined in the combiner 4048, so that the power of the second frequency signal output by the mixing module is higher (greater than or equal to the power of the signal that the PFD can identify); when the frequency of the first frequency signal is not the target frequency, the signal obtained by the I signal after changing the first phase and the signal obtained by the Q signal after changing the second phase will cancel each other out (partially or completely) when combined in the combiner 4048, so that the power of the second frequency signal output by the mixing module is lower (less than the power of the signal that the PFD can identify).

[0083] In the two states where the difference between the first phase and the second phase is 90 degrees, and the difference between the first phase and the second phase is -90 degrees, the target frequency is different. For example, when the phase of the first power division local oscillator signal is 90 degrees greater than the phase of the second power division local oscillator signal, if the first phase is 90 degrees greater than the second phase (for example, the first phase is 90 degrees and the second phase is 0 degrees; for example, the first phase is 95 degrees and the second phase is 5 degrees), the target frequency is FLO1+Fref, FLO1 represents the above-mentioned first initial local oscillator signal, and Fref represents the reference signal. If the frequency of the first frequency signal output by the VCO is FLO1+Fref, the PFD and the first filter will not adjust the driving voltage of the VCO, so that the phase-locked frequency synthesizer can lock the output frequency at FLO1+Fref. If the frequency of the first frequency signal output by the VCO is FLO1-Fref, the PFD and the first filter will adjust the driving voltage of the VCO, thereby preventing the phase-locked frequency synthesizer from locking the output frequency at FLO1-Fref.

[0084] In the case where the phase of the first power division local oscillator signal is 90 degrees greater than the phase of the second power division local oscillator signal, if the first phase is 90 degrees less than the second phase (for example, the first phase is 0 degrees and the second phase is 90 degrees; for example, the first phase is 5 degrees and the second phase is 95 degrees), the target frequency is FLO1-Fref. If the frequency of the first frequency signal output by the VCO is FLO1-Fref, the PFD and the first filter will not adjust the driving voltage of the VCO, so that the phase-locked frequency synthesizer can lock the output frequency at FLO1-Fref. If the frequency of the first frequency signal output by the VCO is FLO1+Fref, the PFD and the first filter will adjust the driving voltage of the VCO, thereby preventing the phase-locked frequency synthesizer from locking the output frequency at FLO1+Fref. The present application can change the frequency of the signal output by the phase-locked frequency synthesizer by tuning FLO1.

[0085] It can be seen that the present application can set the first phase and the second phase according to the target frequency selected as needed.

[0086] Optionally, please continue to refer to Figure 5 , the frequency mixing module 404 also includes: a controller 4049, the controller 4049 is connected to the first phase shifter 4046 and the second phase shifter 4047; the controller 4049 is used to control the first phase shifter 4046 to adjust the first phase, and control the second phase shifter 4047 to adjust the second phase. In this case, the first phase shifter 4046 and the second phase shifter 4047 are both adjustable phase shifters. It can be seen that the present application can also set the first phase and the second phase through the controller 4049.

[0087] It is understandable that one of the first phase shifter 4046 and the second phase shifter 4047 may be an adjustable phase shifter, and the other phase shifter may not be an adjustable phase shifter. In this case, the controller 4049 is connected to the one phase shifter to control the phase shifter to adjust its phase (such as the first phase or the second phase). When the frequency mixing module also includes a controller, the first phase shifter and the second phase shifter may not be adjustable phase shifters. In this case, the controller may also set the first phase of the first phase shifter and the second phase of the second phase shifter, and the first phase and the second phase are fixed. The frequency mixing module may also not include a controller, and the first phase of the first phase shifter and the second phase of the second phase shifter are pre-set.

[0088] (2) For example, Figure 6 A structural diagram of another frequency mixing module 404 provided in an embodiment of the present application is shown in FIG. Figure 6As shown, the mixing module 404 includes: a first power divider 4041, a first mixer 4042, a second mixer 4043, a first local oscillator signal source 4044, a 90-degree power divider 4045, a first phase shifter 4046, a second phase shifter 4047, a combiner 4048, a third mixer 4050, a fourth mixer 4051, a second local oscillator signal source 4052 and a second power divider 4053.

[0089] The output end of VCO 403, the first power divider 4041, the first mixer 4042, the third mixer 4050, the combiner 4048 and the input end of PFD 401 are connected in series; the output end of VCO 403, the first power divider 4041, the second mixer 4043, the fourth mixer 4051, the combiner 4048 and the PFD The input end of 401 is connected in series; the first local oscillator signal source 4044, the 90-degree power divider 4045 and the first mixer 4042 are connected in series, the first local oscillator signal source 4044, the 90-degree power divider 4045 and the second mixer 4043 are connected in series; the second local oscillator signal source 4052, the second power divider 4053, the first phase shifter 4046 and the third mixer 4050 are connected in series, the second local oscillator signal source 4052, the second power divider 4053, the second phase shifter 4047 and the fourth mixer 4051 are connected in series;

[0090] The first phase shifter 4046 is used to change the phase of the passing signal to a first phase, and the second phase shifter 4047 is used to change the phase of the passing signal to a second phase, and the absolute value of the difference between the first phase and the second phase is 90 degrees; the first local oscillator signal source based on which the mixing module 404 outputs the second frequency signal is used to provide a first initial local oscillator signal, and the second local oscillator signal source is used to provide a second initial local oscillator signal.

[0091] For example, when the mixing module 404 outputs the second frequency signal according to the first frequency signal, the 90-degree power divider 4045 is used to transmit the first power-divided local oscillator signal to the first mixer 4042 based on the first initial local oscillator signal, and transmit the second power-divided local oscillator signal to the second mixer 4043. The 90-degree power divider 4045 can divide the first initial local oscillator signal into two signals, and obtain the first power-divided local oscillator signal and the second power-divided local oscillator signal by adjusting the phase of at least one of the two signals. In addition, the phases of the first power-divided local oscillator signal and the second power-divided local oscillator signal differ by 90 degrees. The 90-degree power divider 4045 may be a proportional power divider or may not be a proportional power divider, and this application does not limit this. The two signals obtained by the proportional power divider by dividing a signal have the same power.

[0092] When the mixing module 404 outputs the second frequency signal according to the first frequency signal, the first power divider 4041 is used to transmit the first frequency power divided signal to the first mixer 4042 based on the first frequency signal from the VCO 403, and transmit the second frequency power divided signal to the second mixer 4043. It can be seen that after the first power divider 4041 divides the first frequency signal, it obtains the first frequency power divided signal and the second frequency power divided signal, and transmits the first frequency power divided signal to the first mixer 4042, and transmits the second frequency power divided signal to the second mixer 4043. The first power divider 4041 may be a proportional power divider, or may not be a proportional power divider, and this application does not limit this. It can be seen that at least one power divider in the mixing module 404 is a proportional power divider, or all power dividers in the mixing module 404 are not proportional power dividers.

[0093] The first mixer 4042 mixes the first frequency power division signal from the first power divider 4041 with the first power division local oscillator signal from the 90-degree power divider 4045 and outputs the mixed signal to the third mixer 4050. The second mixer 4043 mixes the second frequency power division signal from the first power divider 4041 with the second power division local oscillator signal from the 90-degree power divider 4045 and outputs the mixed signal to the fourth mixer 4051. Since the first power division local oscillator signal and the second power division local oscillator signal differ in phase by 90 degrees, the first power division local oscillator signal and the second power division local oscillator signal are orthogonal. The first frequency power division signal and the second frequency power division signal are both obtained by power division of the first frequency signal, so the first frequency power division signal and the second frequency power division signal have the same phase, and the signal obtained by mixing the first frequency power division signal with the first power division local oscillator signal (which can be called an I signal) is orthogonal to the signal obtained by mixing the second frequency power division signal with the second power division local oscillator signal (which can be called a Q signal).

[0094] The second local oscillator signal source 4052 is used to provide a second initial local oscillator signal to the second power divider 4053; the second power divider 4053 will power divide the second initial local oscillator signal into a third power division local oscillator signal and a fourth power division local oscillator signal, and transmit the third power division local oscillator signal to the first phase shifter 4046, and transmit the fourth power division local oscillator signal to the second phase shifter 4047. The second power divider 4053 may be an equal-proportional power divider or may not be an equal-proportional power divider, which is not limited in the present application. When the second power divider 4053 is an equal-proportional power divider, the power of the third frequency power division signal and the fourth frequency power division signal are the same.

[0095] The first phase shifter 4046 changes the phase of the third power division local oscillator signal from the second power divider 4053 by a first phase and transmits it to the third mixer 4050; the second phase shifter 4047 changes the phase of the fourth power division local oscillator signal from the second power divider 4053 by a second phase and transmits it to the fourth mixer.

[0096] The third mixer 4050 mixes the signal from the first mixer 4042 with the signal from the first phase shifter 4046 and transmits the mixed signal to the combiner 4048; the fourth mixer 4051 mixes the signal from the second mixer 4043 with the signal from the second phase shifter 4047 and transmits the mixed signal to the combiner 4048; the combiner 4048 combines the signal from the third mixer 4050 with the signal from the fourth mixer 4051 and outputs the mixed signal.

[0097] Here, the absolute value of the difference between the first phase and the second phase is 90 degrees, for example, the difference between the first phase and the second phase is 90 degrees, or the difference between the first phase and the second phase is -90 degrees. By setting the absolute value of the difference between the first phase and the second phase to 90 degrees, the signal output by the third mixer 4050 and the signal output by the fourth mixer 4051 are combined in the combiner 4048, and the above-mentioned second frequency signal can be obtained. When the frequency of the first frequency signal is the target frequency, the signal output by the third mixer 4050 and the signal output by the fourth mixer 4051 will not cancel each other in power when combined in the combiner 4048, so that the power of the second frequency signal output by the mixing module is higher (greater than or equal to the power of the signal that the PFD can identify); when the frequency of the first frequency signal is not the target frequency, the signal output by the third mixer 4050 and the signal output by the fourth mixer 4051 will cancel each other (partially or completely) when combined in the combiner 4048, so that the power of the second frequency signal output by the mixing module is lower (less than the power of the signal that the PFD can identify).

[0098] In the two states where the difference between the first phase and the second phase is 90 degrees and the difference between the first phase and the second phase is -90 degrees, the target frequency is different. For example, when the phase of the first power division local oscillator signal is 90 degrees greater than the phase of the second power division local oscillator signal, if the first phase is 90 degrees greater than the second phase (for example, the first phase is 90 degrees and the second phase is 0 degrees; for example, the first phase is 95 degrees and the second phase is 5 degrees), the target frequency is FLO1+FLO2+Fref, and FLO2 represents the above-mentioned second initial local oscillator signal. If the frequency of the first frequency signal output by the VCO is FLO1+FLO2+Fref, the PFD and the first filter will not adjust the driving voltage of the VCO, so that the phase-locked frequency synthesizer can lock the output frequency at FLO1+FLO2+Fref. If the frequency of the first frequency signal output by the VCO is FLO1-FLO2-Fref, the PFD and the first filter will adjust the driving voltage of the VCO, thereby preventing the phase-locked frequency synthesis device from incorrectly locking the output frequency at FLO1-FLO2-Fref.

[0099] In the case where the phase of the first power division local oscillator signal is 90 degrees greater than the phase of the second power division local oscillator signal, if the first phase is 90 degrees less than the second phase (for example, the first phase is 0 degrees and the second phase is 90 degrees; for example, the first phase is 5 degrees and the second phase is 95 degrees), the target frequency is FLO1-FLO2-Fref. If the frequency of the first frequency signal output by the VCO is FLO1-FLO2-Fref, the PFD and the first filter will not adjust the driving voltage of the VCO, so that the phase-locked frequency synthesizer can lock the output frequency at FLO1-FLO2-Fref. If the frequency of the first frequency signal output by the VCO is FLO1+FLO2+Fref, the PFD and the first filter will adjust the driving voltage of the VCO, thereby preventing the phase-locked frequency synthesizer from locking the output frequency at FLO1+FLO2+Fref. The present application can change the frequency of the signal output by the phase-locked frequency synthesizer by tuning FLO1 and FLO2.

[0100] It can be seen that the present application can set the first phase and the second phase according to the target frequency selected as needed.

[0101] Optionally, please continue to refer to Figure 6 , the frequency mixing module 404 also includes: a controller 4049, the controller 4049 is connected to the first phase shifter 4046 and the second phase shifter 4047; the controller 4049 is used to control the first phase shifter 4046 to adjust the first phase, and control the second phase shifter 4047 to adjust the second phase. In this case, the first phase shifter 4046 and the second phase shifter 4047 are both adjustable phase shifters. It can be seen that the first phase and the second phase can also be set by the controller 4049 in the present application.

[0102] It is understandable that one of the first phase shifter 4046 and the second phase shifter 4047 may be an adjustable phase shifter, and the other phase shifter may not be an adjustable phase shifter. In this case, the controller 4049 is connected to the one phase shifter to control the phase shifter to adjust its phase (such as the first phase or the second phase). When the frequency mixing module also includes a controller, the first phase shifter and the second phase shifter may not be adjustable phase shifters. In this case, the controller may also set the first phase of the first phase shifter and the second phase of the second phase shifter, and the first phase and the second phase are fixed. The frequency mixing module may also not include a controller, and the first phase of the first phase shifter and the second phase of the second phase shifter are pre-set.

[0103] in addition, Figure 6 The phase-locked frequency synthesizer shown includes a multi-stage mixer, thereby being able to achieve multi-stage frequency conversion. The number of frequency conversion stages is positively correlated with the frequency tuning range of the signal output by the phase-locked frequency synthesizer. Figure 6When the frequency conversion level of the phase-locked frequency synthesizer shown is high, Figure 6 The phase-locked frequency synthesis arrangement shown is capable of achieving wideband frequency tuning.

[0104] Furthermore, in the above embodiment, the combiner in the mixing module 404 is directly connected to the input end of the PFD 401 as an example. It can be understood that the input end of the combiner in the mixing module 404 and the PFD 401 can also be indirectly connected through other devices. In this case, the signal output by the combiner is not the second frequency signal. The signal output by the combiner is converted into the second frequency signal after passing through these other devices and transmitted to the PFD.

[0105] Optionally, these other devices may include at least one of a frequency divider and a second filter. The frequency division coefficient of the frequency divider may be greater than 1 or less than 1, and the frequency division coefficient may be an integer or a decimal. The frequency divider is used to divide the frequency of the passing signal, and the second filter is used to filter the passing signal. In the case where the other device includes a frequency divider and a second filter, the input end of the combiner, the second filter, the frequency divider and the PFD may be connected in series, or the input end of the combiner, the frequency divider, the second filter and the PFD may be connected in series. For example, assuming that in the mixing module Figure 5 and Figure 6 The part shown is called the mixing part, so in Figure 4 Based on the phase-locked frequency synthesis device shown in FIG. 1 , if the frequency mixing module 404 includes a frequency divider X1, a second filter X2 and the frequency mixing part X3, the phase-locked frequency synthesis device is as follows: Figure 7 shown.

[0106] When these other devices include a frequency divider, the coefficient of the frequency divider is positively correlated with the frequency tuning step of the signal output by the phase-locked frequency synthesizer. Therefore, when the coefficient of the frequency divider is small, the frequency tuning step (such as sub-hertz tuning step) of the signal output by the phase-locked frequency synthesizer is small, which is conducive to achieving accurate tuning of the frequency of the signal output by the phase-locked frequency synthesizer. Since the mixing module also has the function of frequency conversion, the frequency division coefficient of the frequency divider can be set smaller, thereby avoiding the large phase noise introduced by setting the frequency division coefficient of the frequency divider larger.

[0107] When these other components include frequency dividers, if the above mixing section is Figure 5 As shown, the phase-locked frequency synthesis device can lock the frequency of the output frequency signal at FLO1-N*Fref or FLO1+N*Fref; if the above-mentioned mixing part is as Figure 6As shown, the phase-locked frequency synthesizer can lock the frequency of the output frequency signal at FLO1-FLO2-N*Fref or FLO1+FLO2+N*Fref. Wherein, N represents the frequency division coefficient of the frequency divider, and N can be an integer or a decimal greater than 1 (such as 1.215, 1.135, etc.). Therefore, the present application can change the frequency of the signal output by the phase-locked frequency synthesizer by tuning FLO1 (or FLO1 and FLO2) and N to generate a broadband microwave signal with a small tuning step.

[0108] The second filter is used to filter out the spurious signals and interference signals generated by the above-mentioned mixing part. The second filter can be a low-pass filter. When the above-mentioned other devices include a frequency divider, the cut-off frequency of the second filter needs to be higher than N×Fref. When the above-mentioned other devices do not include a frequency divider, the cut-off frequency of the second filter needs to be higher than Fref.

[0109] Based on any phase-locked frequency synthesis device provided in the embodiments of the present application, the embodiments of the present application also provide a phase-locked frequency synthesis method performed by the phase-locked frequency synthesis device. For example, the phase-locked frequency synthesis device includes: a PFD, a first filter, a VCO and a mixing module; the output end of the PFD, the first filter and the input end of the VCO are connected in series, and the output end of the VCO, the mixing module and the input end of the PFD are connected in series. Figure 8 As shown, the method includes:

[0110] S101 . The VCO outputs a first frequency signal under the action of a driving voltage.

[0111] For example, the frequency of the first frequency signal fvco=f0+K0*Vc, where f0 is a constant, K0 is the voltage control sensitivity, and Vc is the driving voltage. The output end of the VCO is also the output end of the phase-locked frequency synthesizer, and the first frequency signal output by the VCO will output the phase-locked frequency synthesizer.

[0112] S102. The frequency mixing module outputs a second frequency signal according to the first frequency signal; the second frequency signal is used to indicate whether the frequency of the first frequency signal is the target frequency.

[0113] The second frequency signal is used to indicate whether the frequency of the first frequency signal is the target frequency. For example, when the frequency of the first frequency signal is the target frequency, the power of the second frequency signal is within the target power range; when the frequency of the first frequency signal is not the target frequency, the power of the second frequency signal is outside the target power range. The target power range can be any power range, for example, the power within the target power range is greater than or equal to the power of the signal that the PFD can recognize, and the power outside the target power range is less than the power of the signal that the PFD can recognize.

[0114] Of course, the power within the target power range and the power outside the target power range may be greater than or equal to the power of the signal that the PFD can identify, or less than the power of the signal that the PFD can identify. The second frequency signal may also indicate whether the frequency of the first frequency signal is the target frequency without determining whether the power is within the target power range. For example, the second frequency signal may indicate whether the frequency of the first frequency signal is the target frequency through parameters such as frequency and phase.

[0115] Here, the frequency mixing module includes a mixer and other devices, which are not limited in the present application. Usually, the frequency of the signal output by the VCO is higher, while the frequency of the signal processed by the PFD is lower, so the frequency of the second frequency signal output by the frequency mixing module is lower than the frequency of the first frequency signal. Of course, the frequency of the second frequency signal output by the frequency mixing module may also be greater than or equal to the frequency of the first frequency signal, which is not limited in the present application embodiment.

[0116] S103 . The PFD outputs a voltage adjustment signal when the second frequency signal indicates that the frequency of the first frequency signal is not the target frequency.

[0117] The voltage adjustment signal may be a voltage signal or a current signal. The PFD may be an analog phase detector (such as a multiplier, etc.) or a digital phase detector (such as a gate phase detector, etc.). Accordingly, the PFD may not output the voltage adjustment signal when the second frequency signal indicates that the frequency of the first frequency signal is the target frequency.

[0118] For example, when the power within the target power range is greater than or equal to the power of the signal that the PFD can recognize, and the power outside the target power range is less than the power of the signal that the PFD can recognize, if the PFD cannot recognize the signal from the mixing module, it is considered that the power of the signal is outside the target power range, and the second frequency signal indicates that the frequency of the first frequency signal is not the target frequency; if the PFD can recognize the signal from the mixing module, it is considered that the power of the signal is within the target power range, and the second frequency signal indicates that the frequency of the first frequency signal is the target frequency.

[0119] When it is determined that the second frequency signal indicates that the frequency of the first frequency signal is not the target frequency, the PFD can determine a phase difference based on the second frequency signal and a reference signal (which can be a signal generated by the PFD or a signal provided to the PFD by a reference signal source), and output a voltage adjustment signal based on the phase difference. The phase difference can be the phase difference between the second frequency signal and the reference signal, or it can be the phase difference between other preset signals and the reference signal. For example, assuming that the PFD cannot identify the second frequency signal when the second frequency signal indicates that the frequency of the first frequency signal is not the target frequency, the phase difference can be the phase difference between other preset signals and the reference signal. Assuming that the PFD can identify the second frequency signal when the second frequency signal indicates that the frequency of the first frequency signal is not the target frequency, the phase difference can be the phase difference between the second frequency signal and the reference signal.

[0120] In addition, when the second frequency signal indicates that the frequency of the first frequency signal is the target frequency, the PFD may determine a phase difference between the second frequency signal and the reference frequency signal, and the phase difference may be a specified phase difference.

[0121] S104: The first filter adjusts the driving voltage according to the voltage adjustment signal.

[0122] The first filter is also called a loop filter. The first filter can adjust the driving voltage of the VCO according to the voltage adjustment signal provided by the PFD to adjust the frequency of the frequency signal (such as the first frequency signal) output by the VCO. For example, the first filter is used to filter out high-frequency noise and interference from the voltage adjustment signal provided by the PFD, and transmit the filtered signal to the VCO to use the signal to adjust the driving voltage of the VCO.

[0123] The first filter can be a passive filter or an active filter. When the first filter is an active filter, it is beneficial to tune the frequency of the signal output by the VCO to a large extent to provide a certain gain. At the same time, the first filter also has the function of smoothing the PFD output, ensuring the stability of the phase-locked frequency synthesizer, and improving the tracking performance and noise characteristics of the phase-locked frequency synthesizer.

[0124] In this way, the frequency signal output by the VCO can be locked to a specified target frequency. The target frequency here can be any frequency, such as microwave frequency, millimeter wave frequency, etc.

[0125] The second frequency signal is used to prevent the VCO from outputting a signal with a non-target frequency. The mixing module can output the second frequency signal according to whether the frequency of the first frequency signal is the target frequency, so that the PFD and the first filter adjust the driving voltage of the VCO when the second frequency signal indicates that the frequency of the first frequency signal is not the target frequency, and finally the frequency of the frequency signal output by the VCO is locked to the specified target frequency instead of the non-target frequency, thereby preventing the phase-locked frequency synthesis device from being mislocked.

[0126] The phase noise introduced when the device is connected in series between the output end of the VCO and the input end of the PFD is lower than the phase noise introduced when the device is connected to the input end of the VCO. Therefore, the phase noise introduced by the mixing module connected in series between the output end of the VCO and the input end of the PFD is lower than the phase noise introduced by the DAC connected to the input end of the VCO. Therefore, the phase noise introduced by the mixing module in the present application is low, so that the phase noise of the frequency signal output by the phase-locked frequency synthesis device is small. In addition, when the device is not connected to the input end of the VCO, the device will not pull the frequency offset of the frequency signal output by the VCO (or the probability of the frequency offset of the frequency signal output by the mixing module is low). Therefore, the probability of the phase-locked frequency synthesis device losing lock can be reduced. In addition, the phase-locked frequency synthesis device provided in the embodiment of the present application does not use multiple feedback loops, so the complexity of the phase-locked frequency synthesis device is low, the cost is low, the area is small, the power consumption is also small, and more phase noise will not be introduced due to multiple feedback loops.

[0127] The frequency mixing module can be implemented in various ways, so the frequency mixing module in S102 outputs the second frequency signal according to the first frequency signal in various ways. The following will take two of the implementable ways as examples for explanation. It is understandable that the implementable ways of the frequency mixing module may also be different from the following two implementable ways.

[0128] (1) For example, in the structure of the mixing module, Figure 5 As shown, for example, Fig. 9 As shown, S102 includes:

[0129] S1021A, the 90-degree power divider transmits a first power-divided local oscillator signal to the first mixer based on the first initial local oscillator signal, and transmits a second power-divided local oscillator signal to the second mixer.

[0130] The 90-degree power divider 4045 can divide the first initial local oscillator signal into two signals, and obtain the first power-divided local oscillator signal and the second power-divided local oscillator signal by adjusting the phase of at least one of the two signals. Moreover, the phases of the first power-divided local oscillator signal and the second power-divided local oscillator signal differ by 90 degrees. The 90-degree power divider 4045 may be a proportional power divider or may not be a proportional power divider, and this is not limited in the present application. The two signals obtained by a proportional power divider by dividing a signal have the same power, so when the 90-degree power divider 4045 is a proportional power divider, the power of the first power-divided local oscillator signal and the second power-divided local oscillator signal are the same.

[0131] S1022A: The first power divider transmits a first frequency power divided signal to the first mixer based on the first frequency signal from the VCO, and transmits a second frequency power divided signal to the second mixer.

[0132] It can be seen that after the first power divider 4041 divides the power of the first frequency signal, it obtains a first frequency power divided signal and a second frequency power divided signal, and transmits the first frequency power divided signal to the first mixer 4042, and transmits the second frequency power divided signal to the second mixer 4043. The first power divider 4041 may be an equal-proportional power divider, or may not be an equal-proportional power divider, and this application does not limit this. It can be seen that at least one power divider in the mixer module 404 is an equal-proportional power divider, or all power dividers in the mixer module 404 are not equal-proportional power dividers. When the first power divider 4041 is an equal-proportional power divider, the power of the first frequency power divided signal and the second frequency power divided signal are the same.

[0133] S1023A, the first mixer mixes the first frequency power division signal from the first power divider with the first power division local oscillator signal from the 90-degree power divider and outputs the mixed signals to the first phase shifter.

[0134] S1024A, the second mixer mixes the second frequency power division signal from the first power divider with the second power division local oscillator signal from the 90-degree power divider and outputs the mixed signals to the second phase shifter.

[0135] Since the phase difference between the first power division local oscillator signal and the second power division local oscillator signal is 90 degrees, the first power division local oscillator signal and the second power division local oscillator signal are orthogonal. The first frequency power division signal and the second frequency power division signal are both obtained by power division of the first frequency signal. Therefore, the first frequency power division signal and the second frequency power division signal have the same phase. The signal obtained by mixing the first frequency power division signal with the first power division local oscillator signal (which can be called an I signal) is orthogonal to the signal obtained by mixing the second frequency power division signal with the second power division local oscillator signal (which can be called a Q signal).

[0136] S1025A, the first phase shifter changes the phase of the signal from the first mixer by a first phase and outputs the signal to the combiner.

[0137] S1026A, the second phase shifter changes the phase of the signal from the second mixer to a second phase and outputs the signal to the combiner.

[0138] S1027A, the combiner combines the signal from the first phase shifter and the signal from the second phase shifter and outputs the combined signal.

[0139] The absolute value of the difference between the first phase and the second phase is 90 degrees, for example, the difference between the first phase and the second phase is 90 degrees, or the difference between the first phase and the second phase is -90 degrees. By setting the absolute value of the difference between the first phase and the second phase to 90 degrees, the signal obtained by the I signal after changing the first phase and the signal obtained by the Q signal after changing the second phase are combined in the combiner 4048, and the above-mentioned second frequency signal can be obtained. When the frequency of the first frequency signal is the target frequency, the signal obtained by the I signal after changing the first phase and the signal obtained by the Q signal after changing the second phase will not cancel each other out in power when combined in the combiner 4048, so that the power of the second frequency signal output by the mixing module is higher (greater than or equal to the power of the signal that the PFD can identify); when the frequency of the first frequency signal is not the target frequency, the signal obtained by the I signal after changing the first phase and the signal obtained by the Q signal after changing the second phase will cancel each other out (partially or completely) when combined in the combiner 4048, so that the power of the second frequency signal output by the mixing module is lower (less than the power of the signal that the PFD can identify).

[0140] In the two states where the difference between the first phase and the second phase is 90 degrees, and the difference between the first phase and the second phase is -90 degrees, the target frequency is different. For example, when the phase of the first power division local oscillator signal is 90 degrees greater than the phase of the second power division local oscillator signal, if the first phase is 90 degrees greater than the second phase (for example, the first phase is 90 degrees and the second phase is 0 degrees; for example, the first phase is 95 degrees and the second phase is 5 degrees), the target frequency is FLO1+Fref, FLO1 represents the above-mentioned first initial local oscillator signal, and Fref represents the reference signal. If the frequency of the first frequency signal output by the VCO is FLO1+Fref, the PFD and the first filter will not adjust the driving voltage of the VCO, so that the phase-locked frequency synthesizer can lock the output frequency at FLO1+Fref. If the frequency of the first frequency signal output by the VCO is FLO1-Fref, the PFD and the first filter will adjust the driving voltage of the VCO, thereby preventing the phase-locked frequency synthesizer from locking the output frequency at FLO1-Fref.

[0141] In the case where the phase of the first power division local oscillator signal is 90 degrees greater than the phase of the second power division local oscillator signal, if the first phase is 90 degrees less than the second phase (for example, the first phase is 0 degrees and the second phase is 90 degrees; for example, the first phase is 5 degrees and the second phase is 95 degrees), the target frequency is FLO1-Fref. If the frequency of the first frequency signal output by the VCO is FLO1-Fref, the PFD and the first filter will not adjust the driving voltage of the VCO, so that the phase-locked frequency synthesizer can lock the output frequency at FLO1-Fref. If the frequency of the first frequency signal output by the VCO is FLO1+Fref, the PFD and the first filter will adjust the driving voltage of the VCO, thereby preventing the phase-locked frequency synthesizer from locking the output frequency at FLO1+Fref. The present application can change the frequency of the signal output by the phase-locked frequency synthesizer by tuning FLO1.

[0142] It can be seen that the present application can set the first phase and the second phase according to the target frequency selected as needed.

[0143] (2) For example, the structure of the mixing module 404 is as follows: Figure 6 As shown, for example, Fig.10 As shown, S102 includes:

[0144] S1021B, the 90-degree power divider transmits a first power-divided local oscillator signal to the first mixer based on the first initial local oscillator signal, and transmits a second power-divided local oscillator signal to the second mixer.

[0145] The 90-degree power divider 4045 can divide the first initial local oscillator signal into two signals, and adjust the phase of at least one of the two signals to obtain a first power-divided local oscillator signal and a second power-divided local oscillator signal. In addition, the first power-divided local oscillator signal and the second power-divided local oscillator signal have a phase difference of 90 degrees. The 90-degree power divider 4045 may be a proportional power divider or may not be a proportional power divider, and this application does not limit this. The two signals obtained by the proportional power divider by dividing a signal have the same power.

[0146] S1022B: The first power divider transmits a first frequency power divided signal to the first mixer based on the first frequency signal from the VCO, and transmits a second frequency power divided signal to the second mixer.

[0147] It can be seen that after the first power divider 4041 divides the first frequency signal, it obtains a first frequency power divider signal and a second frequency power divider signal, and transmits the first frequency power divider signal to the first mixer 4042, and transmits the second frequency power divider signal to the second mixer 4043. The first power divider 4041 can be a proportional power divider, or it can be a non-proportional power divider, which is not limited in this application. It can be seen that at least one power divider in the mixer module 404 is a proportional power divider, or all power dividers in the mixer module 404 are not proportional power dividers.

[0148] S1023B: The first mixer mixes the first frequency power division signal from the first power divider with the first power division local oscillator signal from the 90-degree power divider and outputs the mixed signals to the third mixer.

[0149] S1024B, the second mixer mixes the second frequency power division signal from the first power divider with the second power division local oscillator signal from the 90-degree power divider and outputs the mixed signals to the fourth mixer.

[0150] Since the phase difference between the first power division local oscillator signal and the second power division local oscillator signal is 90 degrees, the first power division local oscillator signal and the second power division local oscillator signal are orthogonal. The first frequency power division signal and the second frequency power division signal are both obtained by power division of the first frequency signal. Therefore, the first frequency power division signal and the second frequency power division signal have the same phase. The signal obtained by mixing the first frequency power division signal with the first power division local oscillator signal (which can be called an I signal) is orthogonal to the signal obtained by mixing the second frequency power division signal with the second power division local oscillator signal (which can be called a Q signal).

[0151] S1025B. The second local oscillator signal source provides a second initial local oscillator signal to the second power divider.

[0152] S1026B: The second power divider power divides the second initial local oscillator signal into a third power division local oscillator signal and a fourth power division local oscillator signal, transmits the third power division local oscillator signal to the first phase shifter, and transmits the fourth power division local oscillator signal to the second phase shifter.

[0153] The second power divider 4053 may be an equal-proportional power divider or may not be an equal-proportional power divider, which is not limited in the present application. When the second power divider 4053 is an equal-proportional power divider, the power of the third frequency power divider signal and the fourth frequency power divider signal are the same.

[0154] S1027B, the first phase shifter changes the phase of the third power divided local oscillator signal from the second power divider by a first phase and transmits the phase to the third mixer.

[0155] S1028B. The second phase shifter changes the phase of the fourth power divided local oscillator signal from the second power divider by a second phase and transmits the signal to the fourth mixer.

[0156] S1029B: The third mixer mixes the signal from the first mixer and the signal from the first phase shifter and transmits the mixed signals to the combiner.

[0157] S10210B, the fourth mixer mixes the signal from the second mixer and the signal from the second phase shifter and transmits the mixed signals to the combiner.

[0158] S10211B, the combiner combines the signal from the third mixer and the signal from the fourth mixer and outputs the combined signals.

[0159] Here, the absolute value of the difference between the first phase and the second phase is 90 degrees, for example, the difference between the first phase and the second phase is 90 degrees, or the difference between the first phase and the second phase is -90 degrees. By setting the absolute value of the difference between the first phase and the second phase to 90 degrees, the signal output by the third mixer 4050 and the signal output by the fourth mixer 4051 are combined in the combiner 4048, and the above-mentioned second frequency signal can be obtained. When the frequency of the first frequency signal is the target frequency, the signal output by the third mixer 4050 and the signal output by the fourth mixer 4051 will not cancel each other in power when combined in the combiner 4048, so that the power of the second frequency signal output by the mixing module is higher (greater than or equal to the power of the signal that the PFD can identify); when the frequency of the first frequency signal is not the target frequency, the signal output by the third mixer 4050 and the signal output by the fourth mixer 4051 will cancel each other (partially or completely) when combined in the combiner 4048, so that the power of the second frequency signal output by the mixing module is lower (less than the power of the signal that the PFD can identify).

[0160] In the two states where the difference between the first phase and the second phase is 90 degrees and the difference between the first phase and the second phase is -90 degrees, the target frequency is different. For example, when the phase of the first power division local oscillator signal is 90 degrees greater than the phase of the second power division local oscillator signal, if the first phase is 90 degrees greater than the second phase (for example, the first phase is 90 degrees and the second phase is 0 degrees; for example, the first phase is 95 degrees and the second phase is 5 degrees), the target frequency is FLO1+FLO2+Fref, and FLO2 represents the above-mentioned second initial local oscillator signal. If the frequency of the first frequency signal output by the VCO is FLO1+FLO2+Fref, the PFD and the first filter will not adjust the driving voltage of the VCO, so that the phase-locked frequency synthesizer can lock the output frequency at FLO1+FLO2+Fref. If the frequency of the first frequency signal output by the VCO is FLO1-FLO2-Fref, the PFD and the first filter will adjust the driving voltage of the VCO, thereby preventing the phase-locked frequency synthesis device from incorrectly locking the output frequency at FLO1-FLO2-Fref.

[0161] In the case where the phase of the first power division local oscillator signal is 90 degrees greater than the phase of the second power division local oscillator signal, if the first phase is 90 degrees less than the second phase (for example, the first phase is 0 degrees and the second phase is 90 degrees; for example, the first phase is 5 degrees and the second phase is 95 degrees), the target frequency is FLO1-FLO2-Fref. If the frequency of the first frequency signal output by the VCO is FLO1-FLO2-Fref, the PFD and the first filter will not adjust the driving voltage of the VCO, so that the phase-locked frequency synthesizer can lock the output frequency at FLO1-FLO2-Fref. If the frequency of the first frequency signal output by the VCO is FLO1+FLO2+Fref, the PFD and the first filter will adjust the driving voltage of the VCO, thereby preventing the phase-locked frequency synthesizer from locking the output frequency at FLO1+FLO2+Fref. The present application can change the frequency of the signal output by the phase-locked frequency synthesizer by tuning FLO1 and FLO2.

[0162] It can be seen that the present application can set the first phase and the second phase according to the target frequency selected as needed.

[0163] Optionally, please continue to refer to Figure 5 and Figure 6 , the frequency mixing module 404 also includes: a controller 4049, the controller 4049 is connected to the first phase shifter 4046 and the second phase shifter 4047; S102 also includes: the controller controls the first phase shifter to adjust the first phase, and controls the second phase shifter to adjust the second phase. In this case, the first phase shifter 4046 and the second phase shifter 4047 are both adjustable phase shifters. It can be seen that the present application can also set the first phase and the second phase through the controller 4049.

[0164] It is understandable that one of the first phase shifter 4046 and the second phase shifter 4047 may be an adjustable phase shifter, and the other phase shifter may not be an adjustable phase shifter. In this case, the controller 4049 is connected to the one phase shifter to control the phase shifter to adjust its phase (such as the first phase or the second phase). When the frequency mixing module also includes a controller, the first phase shifter and the second phase shifter may not be adjustable phase shifters. In this case, the controller may also set the first phase of the first phase shifter and the second phase of the second phase shifter, and the first phase and the second phase are fixed. The frequency mixing module may also not include a controller, and the first phase of the first phase shifter and the second phase of the second phase shifter are pre-set.

[0165] in addition, Figure 6 The phase-locked frequency synthesizer shown includes a multi-stage mixer, thereby being able to achieve multi-stage frequency conversion. The number of frequency conversion stages is positively correlated with the frequency tuning range of the signal output by the phase-locked frequency synthesizer. Figure 6When the frequency conversion level of the phase-locked frequency synthesizer shown is high, Figure 6 The phase-locked frequency synthesis arrangement shown is capable of achieving wideband frequency tuning.

[0166] Optionally, the input ends of the combiner and the PFD in the mixing module can be indirectly connected through other devices. In this case, the signal output by the combiner is not the second frequency signal. The signal output by the combiner becomes the second frequency signal after passing through these other devices and is transmitted to the PFD.

[0167] Optionally, these other devices may include at least one of a frequency divider and a second filter, and the frequency division coefficient of the frequency divider may be greater than 1 or less than 1, and the frequency division coefficient may be an integer or a decimal. The frequency divider is used to divide the passing signal, and the second filter is used to filter the passing signal. For example, when these other devices include a frequency divider, the above S102 also includes: the frequency divider divides the signal from the combiner and outputs it. When these other devices include a second filter, the above S102 also includes: the second filter filters the signal from the combiner and outputs it.

[0168] In the case where the other device includes a frequency divider and a second filter, the combiner, the second filter, the frequency divider and the input end of the PFD may be connected in series, or the combiner, the frequency divider, the second filter and the input end of the PFD may be connected in series. Figure 5 and Figure 6 The part shown is called the mixing part, so in Figure 4 Based on the phase-locked frequency synthesis device shown in FIG. 1 , if the frequency mixing module 404 includes a frequency divider X1, a second filter X2 and the frequency mixing part X3, the phase-locked frequency synthesis device is as follows: Figure 7 shown.

[0169] When these other devices include a frequency divider, the coefficient of the frequency divider is positively correlated with the frequency tuning step of the signal output by the phase-locked frequency synthesizer. Therefore, when the coefficient of the frequency divider is small, the frequency tuning step (such as sub-hertz tuning step) of the signal output by the phase-locked frequency synthesizer is small, which is conducive to achieving accurate tuning of the frequency of the signal output by the phase-locked frequency synthesizer. Since the mixing module also has the function of frequency conversion, the frequency division coefficient of the frequency divider can be set smaller, thereby avoiding the large phase noise introduced by setting the frequency division coefficient of the frequency divider larger.

[0170] When these other components include frequency dividers, if the above mixing section is Figure 5 As shown, the phase-locked frequency synthesis device can lock the frequency of the output frequency signal at FLO1-N*Fref or FLO1+N*Fref; if the above-mentioned mixing part is as Figure 6As shown, the phase-locked frequency synthesizer can lock the frequency of the output frequency signal at FLO1-FLO2-N*Fref or FLO1+FLO2+N*Fref. Wherein, N represents the frequency division coefficient of the frequency divider, and N can be an integer or a decimal greater than 1 (such as 1.215, 1.135, etc.). Therefore, the present application can change the frequency of the signal output by the phase-locked frequency synthesizer by tuning FLO1 (or FLO1 and FLO2) and N to generate a broadband microwave signal with a small tuning step.

[0171] The second filter is used to filter out the spurious signals and interference signals generated by the above-mentioned mixing part. The second filter can be a low-pass filter. When the above-mentioned other devices include a frequency divider, the cut-off frequency of the second filter needs to be higher than N×Fref. When the above-mentioned other devices do not include a frequency divider, the cut-off frequency of the second filter needs to be higher than Fref.

[0172] In this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. The term "at least one" refers to one or more, and "multiple" refers to two or more, unless otherwise clearly defined. Different types of embodiments such as method embodiments and device embodiments provided in the embodiments of the present application can refer to each other, and the embodiments of the present application are not limited to this.

[0173] In the corresponding embodiments provided in the present application, it should be understood that the disclosed devices and the like can be implemented by other configuration methods. For example, the device embodiments described above are only schematic, for example, the division of modules is only a logical function division, and there can be other division methods in actual implementation, such as combining or integrating multiple modules into another system, or ignoring or not executing some features. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed is an indirect coupling or communication connection through some interfaces, devices or modules, which is electrical or other forms.

[0174] The units described as separate components may or may not be physically separated, and the components described as units may or may not be physical units, and may be located in one place or distributed on multiple devices. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0175] The above is only an optional implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A phase-locked frequency synthesis device, characterized in that: include: Phase detector PFD, first filter, voltage-controlled crystal oscillator VCO and mixing module; The output end of the PFD, the first filter and the input end of the VCO are connected in series, and the output end of the VCO, the mixing module and the input end of the PFD are connected in series; The VCO is used to output a first frequency signal under the action of a driving voltage; The frequency mixing module is used to output a second frequency signal according to the first frequency signal; the second frequency signal is used to indicate whether the frequency of the first frequency signal is the target frequency; The PFD is configured to output a voltage adjustment signal when the second frequency signal indicates that the frequency of the first frequency signal is not the target frequency; The first filter is used for adjusting the driving voltage according to the voltage adjustment signal.

2. The phase-locked frequency synthesis device according to claim 1, characterized in that: When the frequency of the first frequency signal is the target frequency, the power of the second frequency signal is within the target power range; when the frequency of the first frequency signal is not the target frequency, the power of the second frequency signal is outside the target power range.

3. The phase-locked frequency synthesis device according to claim 2, characterized in that: The power within the target power range is greater than or equal to the power of the signal that the PFD can identify, and the power outside the target power range is less than the power of the signal that the PFD can identify.

4. The phase-locked frequency synthesis device according to claim 3, characterized in that: The mixing module includes: a first power divider, a first mixer, a second mixer, a first local oscillator signal source, a 90-degree power divider, a first phase shifter, a second phase shifter and a combiner; The output end of the VCO, the first power divider, the first mixer, the first phase shifter, the combiner and the input end of the PFD are connected in series; the output end of the VCO, the first power divider, the second mixer, the second phase shifter, the combiner and the input end of the PFD are connected in series; the first local oscillator signal source, the 90-degree power divider and the first mixer are connected in series, and the first local oscillator signal source, the 90-degree power divider and the second mixer are connected in series; The first phase shifter is used to change the phase of the passing signal to a first phase, and the second phase shifter is used to change the phase of the passing signal to a second phase, and the absolute value of the difference between the first phase and the second phase is 90 degrees.

5. The phase-locked frequency synthesis device according to claim 3, characterized in that: The mixing module includes: a first power divider, a first mixer, a second mixer, a first local oscillator signal source, a 90-degree power divider, a first phase shifter, a second phase shifter, a third mixer, a fourth mixer, a second local oscillator signal source, a second power divider and a combiner; The output end of the VCO, the first power divider, the first mixer, the third mixer, the combiner and the input end of the PFD are connected in series; the output end of the VCO, the first power divider, the second mixer, the fourth mixer, the combiner and the input end of the PFD are connected in series; the first local oscillator signal source, the 90-degree power divider and the first mixer are connected in series, and the first local oscillator signal source, the 90-degree power divider and the second mixer are connected in series; the second local oscillator signal source, the second power divider, the first phase shifter and the third mixer are connected in series, and the second local oscillator signal source, the second power divider, the second phase shifter and the fourth mixer are connected in series; The first phase shifter is used to change the phase of the passing signal to a first phase, and the second phase shifter is used to change the phase of the passing signal to a second phase, and the absolute value of the difference between the first phase and the second phase is 90 degrees.

6. The phase-locked frequency synthesis device according to claim 4 or 5, characterized in that: At least one power divider in the mixing module is an equal-proportional power divider.

7. The phase-locked frequency synthesis device according to any one of claims 4 to 6, characterized in that: The frequency mixing module further includes: a controller, the controller being connected to the first phase shifter and the second phase shifter; The controller is used for controlling the first phase shifter to adjust the first phase, and controlling the second phase shifter to adjust the second phase.

8. The phase-locked frequency synthesis device according to any one of claims 4 to 7, characterized in that: The frequency mixing module further includes: a frequency divider connected in series between the combiner and the input port of the PFD.

9. The phase-locked frequency synthesis device according to any one of claims 4 to 8, characterized in that: The frequency mixing module further includes: a second filter connected in series between the combiner and the input port of the PFD.

10. An electronic device, characterized in that: include: A signal processing device, and the phase-locked frequency synthesis device according to any one of claims 1 to 9, wherein the signal processing device is connected to the VCO in the phase-locked frequency synthesis device and is used to process the first frequency signal output by the VCO.

11. A phase-locked frequency synthesis method, characterized in that: The method is performed by the phase-locked frequency synthesis device according to any one of claims 1 to 9, the phase-locked frequency synthesis device comprising: a phase detector PFD, a first filter, a voltage-controlled crystal oscillator VCO and a mixing module; the output end of the PFD, the first filter and the input end of the VCO are connected in series, the output end of the VCO, the mixing module and the input end of the PFD are connected in series, and the method comprises: The VCO outputs a first frequency signal under the action of a driving voltage; The frequency mixing module outputs a second frequency signal according to the first frequency signal; the second frequency signal is used to indicate whether the frequency of the first frequency signal is the target frequency; The PFD outputs a voltage adjustment signal when the second frequency signal indicates that the frequency of the first frequency signal is not the target frequency; The first filter adjusts the driving voltage according to the voltage adjustment signal.

12. The method according to claim 11, characterized in that When the frequency of the first frequency signal is the target frequency, the power of the second frequency signal is within the target power range; when the frequency of the first frequency signal is not the target frequency, the power of the second frequency signal is outside the target power range.

13. The method according to claim 12, characterized in that The power within the target power range is greater than or equal to the power of the signal that the PFD can identify, and the power outside the target power range is less than the power of the signal that the PFD can identify.

14. The method according to claim 13, characterized in that The mixing module includes: a first power divider, a first mixer, a second mixer, a first local oscillator signal source, a 90-degree power divider, a first phase shifter, a second phase shifter and a combiner; the output end of the VCO, the first power divider, the first mixer, the first phase shifter, the combiner and the input end of the PFD are connected in series; the output end of the VCO, the first power divider, the second mixer, the second phase shifter, the combiner and the input end of the PFD are connected in series; the first local oscillator signal source, the 90-degree power divider and the first mixer are connected in series, and the first local oscillator signal source, the 90-degree power divider and the second mixer are connected in series; the first local oscillator signal source is used to provide a first initial local oscillator signal; The frequency mixing module outputs a second frequency signal according to the first frequency signal, including: The 90-degree power divider transmits a first power-divided local oscillator signal to the first mixer based on the first initial local oscillator signal, and transmits a second power-divided local oscillator signal to the second mixer; The first power divider transmits a first frequency power divided signal to the first mixer based on the first frequency signal, and transmits a second frequency power divided signal to the second mixer; The first mixer mixes the first frequency power division signal with the first power division local oscillator signal and outputs the mixed signals; The second mixer mixes the second frequency power division signal with the second power division local oscillator signal and outputs the mixed signals; The first phase shifter changes the phase of the signal from the first mixer by a first phase and then outputs the signal; The second phase shifter changes the phase of the signal from the second mixer to a second phase and outputs the signal; the absolute value of the difference between the first phase and the second phase is 90 degrees; The combiner combines the signal from the first phase shifter and the signal from the second phase shifter and outputs the combined signal.

15. The method according to claim 13, characterized in that The mixing module includes: a first power divider, a first mixer, a second mixer, a first local oscillator signal source, a 90-degree power divider, a first phase shifter, a second phase shifter, a third mixer, a fourth mixer, a second local oscillator signal source, a second power divider and a combiner; the output end of the VCO, the first power divider, the first mixer, the third mixer, the combiner and the input end of the PFD are connected in series; the output end of the VCO, the first power divider, the second mixer, the fourth mixer, the combiner and the PFD The input end is connected in series; the first local oscillator signal source, the 90-degree power divider and the first mixer are connected in series, and the first local oscillator signal source, the 90-degree power divider and the second mixer are connected in series; the second local oscillator signal source, the second power divider, the first phase shifter and the third mixer are connected in series, and the second local oscillator signal source, the second power divider, the second phase shifter and the fourth mixer are connected in series; the first local oscillator signal source is used to provide a first initial local oscillator signal; the second local oscillator signal source is used to provide a second initial local oscillator signal; The frequency mixing module outputs a second frequency signal according to the first frequency signal, including: The 90-degree power divider transmits a first power-divided local oscillator signal to the first mixer based on the first initial local oscillator signal, and transmits a second power-divided local oscillator signal to the second mixer; The first power divider transmits a first frequency power divided signal to the first mixer based on the first frequency signal, and transmits a second frequency power divided signal to the second mixer; The first mixer mixes the first frequency power division signal with the first power division local oscillator signal and outputs the mixed signals; The second mixer mixes the second frequency power division signal with the second power division local oscillator signal and outputs the mixed signals; The second power divider transmits a third power division local oscillator signal to the first phase shifter based on the second initial local oscillator signal, and transmits a fourth power division local oscillator signal to the second phase shifter; The first phase shifter changes the phase of the third power division local oscillator signal by a first phase and then outputs the signal; The second phase shifter changes the phase of the fourth power division local oscillator signal by a second phase and outputs the signal; the absolute value of the difference between the first phase and the second phase is 90 degrees; The third mixer mixes the signal from the first mixer with the signal from the first phase shifter and outputs the mixed signals; The fourth mixer mixes the signal from the second mixer with the signal from the second phase shifter and outputs the mixed signals; The combiner combines the signal from the third mixer and the signal from the fourth mixer and outputs the combined signals.

16. The method according to claim 14 or 15, characterized in that The frequency mixing module further includes: a controller, the controller being connected to the first phase shifter and the second phase shifter; The frequency mixing module outputs a second frequency signal according to the first frequency signal, and further includes: The controller controls the first phase shifter to adjust the first phase, and controls the second phase shifter to adjust the second phase.

17. The method according to any one of claims 14 to 16, characterized in that: The frequency mixing module further includes: a frequency divider, wherein the frequency divider is connected in series between the combiner and the input port of the PFD; The frequency mixing module outputs a second frequency signal according to the first frequency signal, and further includes: The frequency divider divides the frequency of the signal from the combiner and outputs the divided signal.

18. The method according to any one of claims 14 to 17, characterized in that: The frequency mixing module further includes: a second filter, the second filter being connected in series between the combiner and the input port of the PFD; The frequency mixing module outputs a second frequency signal according to the first frequency signal, and further includes: The second filter filters the signal from the combiner and then outputs it.

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