A wideband phase-shift frequency discriminator

Abstract

The application discloses a broadband phase-shifting frequency discriminator, and relates to the field of frequency discriminators, comprising a mixed phase-shifting architecture, a multimode phase discrimination unit, a dynamic signal quality evaluation unit, a control unit and an intelligent preprocessing interface; the mixed phase-shifting architecture comprises a first path and a second path arranged in parallel, the first path is a high-precision digital control phase-shifting path, and the second path is a fast continuous analog phase-shifting path. The mixed phase-shifting architecture combining the digital control phase-shifting path coarse adjustment and the analog phase-shifting path closed-loop fine adjustment is adopted, fast presetting and high-precision tracking of the phase in a wide frequency band are realized, and the problem of insufficient response speed and precision of the traditional scheme is solved; the dynamic signal quality evaluation unit is used for monitoring signal power, signal-to-noise ratio and interference characteristics in real time, and the multimode phase discrimination unit is controlled to adaptively switch a high-sensitivity mode and a high-dynamic-range mode, so that the stability of phase discrimination in a complex electromagnetic environment is ensured.

Description

Technical Field

[0001] This invention relates to the field of frequency discriminators, specifically a broadband phase-shifting frequency discriminator. Background Technology

[0002] Microwave frequency discriminators are key components in radio frequency systems, primarily used to detect frequency or phase changes in input signals and convert them into corresponding error voltages. In systems requiring high-precision frequency tracking and stability, such as radar, communications, and particle accelerators, the performance of the discriminator directly affects the stability and efficiency of the entire system. With the development of wireless and accelerator technologies, higher demands are being placed on the operating bandwidth, response speed, accuracy, and environmental adaptability of frequency discriminators.

[0003] Currently, most common frequency discriminators employ architectures based on fixed phase-shifting networks or single digitally controlled phase shifters. These solutions typically perform phase adjustment mechanically or electronically, achieving frequency discrimination within a narrow frequency band or under fixed operating conditions. In terms of signal processing, traditional frequency discriminators generally only use a single phase-detection mode, lacking real-time sensing and adaptive processing capabilities for input signal quality. Furthermore, existing frequency discriminators often lack integrated online self-calibration and environmental adaptation mechanisms, making their performance susceptible to temperature drift, component aging, and external interference.

[0004] In the aforementioned existing technical solutions, a single phase shift path is difficult to balance large-range coarse adjustment and high-precision fine adjustment, resulting in insufficient tracking accuracy and response speed in broadband fast frequency conversion scenarios. Secondly, the lack of real-time evaluation of signal quality and multi-mode phase detection adaptive switching makes it prone to loss of lock or unstable output in complex electromagnetic environments. Furthermore, due to the lack of self-calibration and environmental parameter perception capabilities during long-term operation, the system is prone to performance drift, resulting in high maintenance and debugging costs. Summary of the Invention

[0005] Based on this, the purpose of this invention is to provide a broadband phase-shifting frequency discriminator to solve the technical problems of existing frequency discriminators, such as insufficient tracking accuracy and response speed in broadband fast frequency conversion scenarios, lack of adaptability to complex signals and environments, and easy drift of long-term working performance.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a broadband phase-shifting frequency discriminator, comprising: a hybrid phase-shifting architecture, a multi-mode phase-detection unit, a dynamic signal quality assessment unit, a control unit, and an intelligent preprocessing interface; the hybrid phase-shifting architecture includes a first path and a second path arranged in parallel, the first path being a high-precision numerically controlled phase-shifting path, and the second path being a fast continuous analog phase-shifting path; the first path is used to perform coarse phase shifting of the input RF signal by a preset step value according to the instructions of the control unit; the second path is used to perform continuous fine phase shifting of the signal after coarse phase shifting by the first path, the fine-tuning amount being controlled in a closed loop based on the real-time output error signal of the frequency discriminator; the multi-mode phase-detection unit is connected to the output terminal of the hybrid phase-shifting architecture, and is used to perform phase detection processing on the phase-shifted signal and output an error voltage signal. The dynamic signal quality assessment unit is used to monitor the power, signal-to-noise ratio, and interference characteristics of the input RF signal in real time. The control unit is communicatively connected to the hybrid phase-shifting architecture, the multi-mode phase detector, and the dynamic signal quality assessment unit, respectively. It is used to coordinate and control the coarse phase shift of the first path and the closed-loop fine-tuning of the second path according to the target operating frequency and the signal quality assessment results, and adaptively configure the operating mode of the multi-mode phase detector. The intelligent preprocessing interface is connected to the output of the multi-mode phase detector and is used to adaptively process the output error voltage signal before outputting it. The control unit is configured to: control the phase shift of the first path according to the target operating frequency, so that the signal phase is preset to a position close to the linear operating point of the frequency detector, and start the closed-loop control of the second path to eliminate residual phase error.

[0007] The present invention is further configured such that the multi-mode phase detection unit has at least two phase detection operating modes, including a high-sensitivity mode and a high dynamic range mode; the high-sensitivity mode is suitable for scenarios where the input signal-to-noise ratio is higher than a first set threshold and there is no strong transient interference; the high dynamic range mode is suitable for scenarios where the input signal-to-noise ratio is lower than the first set threshold or where transient interference power is detected to exceed a second set threshold; the control unit adaptively switches the operating mode of the multi-mode phase detection unit and configures its parameters according to the output of the dynamic signal quality assessment unit.

[0008] The present invention is further configured such that the multimode phase detection unit includes a coherent detection module based on the phase-locked loop principle and an amplitude comparison module based on envelope detection; in the high sensitivity mode, the coherent detection module is mainly enabled; in the high dynamic range mode, or when strong transient interference is detected, the amplitude comparison module is mainly enabled, and the output of the amplitude comparison module is used to assist the coherent detection module in phase recovery.

[0009] The invention is further configured to include a self-calibration module; the self-calibration module includes a micro digitally controlled oscillator, a calibration reference channel, and an internal switching matrix; the internal switching matrix is ​​used to inject the calibration signal generated by the micro digitally controlled oscillator into the input of the hybrid phase-shifting architecture through the calibration reference channel in self-calibration mode; the control unit is also configured to start the self-calibration program during system idle periods or when performance drift is detected, and update the nonlinear compensation parameters and channel mismatch parameters of the hybrid phase-shifting architecture in real time by comparing the processing results of the calibration signal in the reference channel and the main signal channel.

[0010] The invention is further configured to include an environmental parameter sensing module and a mode memory library; the environmental parameter sensing module is used to acquire at least one parameter among device temperature, heat sink temperature, and ambient humidity; the mode memory library is used to store a set of control parameters configured for the hybrid phase-shifting architecture, the multi-mode phase detection unit, and the intelligent preprocessing interface under different combinations of environmental parameters to achieve optimal phase detection performance; the control unit is also configured to: calculate a set of control parameters by matching or interpolating from the mode memory library according to the current environmental parameters, and directly apply them to system initialization to shorten the system stabilization time.

[0011] The present invention is further configured such that the intelligent preprocessing interface is configured to perform scene-based adaptive digital filtering, add signal validity flags, and compress data packaging on the raw error voltage signal output by the frequency discriminator; wherein the algorithm and parameters of the adaptive digital filtering are dynamically adjusted by the control unit according to the results of the dynamic signal quality assessment unit.

[0012] The present invention is further configured to include a system health monitoring module; the system health monitoring module is configured to realize passive intermodulation distortion monitoring function, which introduces a low-power, two-tone test signal into the radio frequency front end of the frequency discriminator, and uses the signal processing resources inside the frequency discriminator to analyze the power of the third-order and fifth-order intermodulation products in the output signal, thereby inferring and reporting the risk of system nonlinear degradation caused by poor connector contact or device aging.

[0013] This invention also discloses a frequency identification and control method based on the above-mentioned broadband phase-shifting frequency discriminator, comprising the following steps: S1: Obtaining current environmental parameters through the environmental parameter sensing module, and loading or generating corresponding optimal initial control parameter sets based on the mode memory library, and initializing the hybrid phase-shifting architecture, multi-mode phase detection unit, and intelligent preprocessing interface; S2: Receiving input radio frequency signals, the dynamic signal quality assessment unit analyzes signal characteristics in real time, and the control unit makes decisions and switches the working mode of the multi-mode phase detection unit accordingly; S3: Calculating the coarse adjustment shift required for the first path according to the target frequency point by the control unit. S4: Activate closed-loop control of the second path, continuously fine-tune the phase based on the error signal output in real time by the multi-mode phase detector unit, and achieve precise phase tracking and locking; S5: During system operation, periodically or when the dynamic signal quality assessment unit detects a sudden change in signal quality, trigger the self-calibration program to update system parameters; S6: Intermittently perform nonlinear health status checks on the system through the system health monitoring module; S7: The intelligent preprocessing interface adaptively processes the final error voltage signal and outputs it for use by the external control system.

[0014] In summary, the present invention has the following main beneficial effects: This invention employs a hybrid phase-shifting architecture combining coarse adjustment of the digitally controlled phase-shifting path with closed-loop fine adjustment of the analog phase-shifting path. This achieves rapid phase presetting and high-precision tracking across a wide bandwidth, solving the problems of insufficient response speed and accuracy in traditional solutions. A dynamic signal quality assessment unit monitors signal power, signal-to-noise ratio, and interference characteristics in real time, and controls the multi-mode phase detector to adaptively switch between high-sensitivity and high-dynamic-range modes, ensuring the stability of phase detection in complex electromagnetic environments. A self-calibration module periodically injects internal calibration signals and compares the processing results, updating nonlinear compensation and channel mismatch parameters. Combined with an environmental parameter sensing module and a mode memory bank pre-stored optimal control parameters, this effectively suppresses performance degradation caused by temperature drift and aging, shortening the stabilization time. Simultaneously, a system health monitoring module detects passive intermodulation distortion and warns of potential nonlinear faults, and an intelligent preprocessing interface performs adaptive filtering and data packaging on the error signal, thereby comprehensively improving the overall performance of the frequency discriminator in terms of wideband fast frequency conversion, environmental adaptability, long-term anti-drift, and intelligent maintenance. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the principle of the present invention; Figure 2 This is a schematic diagram of the principle of the double-balanced mixer of the present invention; Figure 3 This is a flowchart illustrating the working method of the present invention. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0017] The embodiments of the present invention will now be described.

[0018] This invention provides a broadband phase-shifting frequency discriminator, the core of which lies in constructing an intelligent, adaptive, and high-precision frequency / phase error detection system. This system is particularly suitable for applications with stringent requirements for operating bandwidth, response speed, long-term stability, and environmental adaptability, such as automatic frequency control (AFC) systems in particle accelerators, frequency source stabilization in high-performance radars, and local oscillator calibration in broadband communication systems.

[0019] Overall architecture and signal flow: See Figure 1 (Principle Block Diagram) The broadband phase-shifting frequency discriminator provided by this invention mainly includes: a hybrid phase-shifting architecture, a multi-mode phase detection unit, a dynamic signal quality assessment unit, a control unit, an intelligent preprocessing interface, a self-calibration module, an environmental parameter sensing module, a mode memory bank, and a system health monitoring module. The RF signal input terminal of the hybrid phase-shifting architecture is used to receive external input RF signals (e.g., incident wave signals sampled from a microwave source), and its output terminal is connected to one input terminal of the multi-mode phase detection unit. The input terminal of the dynamic signal quality assessment unit is also coupled to the input RF signal path for real-time monitoring of signal characteristics. The control unit is bidirectionally connected to the hybrid phase-shifting architecture, the multi-mode phase detection unit, the dynamic signal quality assessment unit, the self-calibration module, the environmental parameter sensing module, the mode memory bank, the system health monitoring module, and the intelligent preprocessing interface. The output terminal of the multi-mode phase detection unit is connected to the input terminal of the intelligent preprocessing interface, which ultimately outputs a processed error voltage signal. All modules can be integrated into a single microwave package or constituted by a microwave circuit board and a digital control circuit board.

[0020] Detailed description of each component: 1. Hybrid phase-shifting architecture.

[0021] The hybrid phase-shifting architecture is one of the key innovations of this invention, aiming to resolve the contradiction between rapid coarse adjustment and precise fine adjustment over a wide bandwidth. This architecture comprises a first path (a high-precision CNC phase-shifting path) and a second path (a rapid continuous analog phase-shifting path) that are configured in parallel and work together.

[0022] The first path (numerically controlled phase shift path): This path is primarily implemented by a high-precision, wide-bandwidth digitally controlled phase shifter. For example, a six-bit digitally controlled phase shifter chip based on gallium arsenide (GaAs) or silicon-based (SiGe) technology can be used, with a phase shift range covering 0° to 360° (or greater) and a basic phase shift step (LSB) of 5.625°. In a more preferred embodiment, a seven-bit or eight-bit digitally controlled phase shifter can be used to improve the basic step accuracy to 2.8125° or 1.40625° to achieve finer coarse adjustment positioning. This digitally controlled phase shifter receives digital control words sent by the control unit via a Serial Peripheral Interface (SPI) or a parallel bus, thereby completing phase switching and setting within tens of nanoseconds. Its function is to preset the phase of the input RF signal into a wider window near the linear operating point of the frequency discriminator, for example, within ±45° of the midpoint of the linear interval, based on prior information about the target operating frequency or instructions from the control unit. This process achieves a wide-range, rapid "coarse adjustment" of the phase.

[0023] The second path (analog phase-shifting path): This path is connected in parallel or cascaded with the first path, and its core is a continuously adjustable analog phase shifter. Specifically, a voltage-controlled phase shifter (VCP) based on a varactor diode or an integrated analog phase shifter based on vector modulation principles can be used. The phase shift amount in this path is not controlled by discrete digital codes, but is continuously adjusted by an analog control voltage generated by a high-precision digital-to-analog converter (DAC). This DAC is driven by a control unit. The key to the second path is forming a closed-loop control: the adjustment amount of its analog control voltage is dynamically generated directly from the error voltage signal output in real time by the multi-mode phase detector unit (or the signal processed by the control unit) through an analog integrator or a digital PID controller. In this way, the second path can perform real-time, continuous "fine-tuning" and tracking of the small phase errors remaining after the coarse adjustment of the first path, as well as phase fluctuations caused by temperature drift, device aging, or slow signal changes, precisely locking the operating point at the center of the linear region with the highest phase detection sensitivity.

[0024] 2. Multimode phase detector unit.

[0025] The multi-mode phase comparison unit is responsible for the core phase comparison function and has the ability to adaptively switch operating modes.

[0026] Basic Components: This unit includes a coherent detection module based on the phase-locked loop (PLL) principle and an amplitude comparison module based on envelope detection. The coherent detection module can be a double-balanced mixer (such as...). Figure 2As shown, its radio frequency (RF) port and local oscillator (LO) port receive the phase-shifted signal from the hybrid phase-shifting architecture output and a reference signal (e.g., a reflected wave signal sampled from the accelerator tube resonator), respectively. The mixer's intermediate frequency (IF) output is a low-frequency error voltage proportional to the sine or cosine function of the phase difference between the two input signals. This is a high-sensitivity mode that provides extremely high phase detection accuracy when the signal-to-noise ratio is good.

[0027] Amplitude Comparison Module: This module contains two peak detectors that detect the envelopes of the two input signals (RF and LO signals) to obtain their voltage amplitude values. Then, through an analog divider or a digital division operation implemented by the control unit, the amplitude ratio of the two signals is obtained. In a preferred calibration process, the system establishes an "amplitude ratio - phase difference" lookup table. During operation, the approximate phase difference can be deduced by querying the real-time amplitude ratio. This is the high dynamic range mode, which is insensitive to the absolute phase of the signal. Even when the signal exhibits deep amplitude modulation or strong transient interference causes coherent detection to lose lock, it can still provide a reliable and unambiguous phase estimate.

[0028] Mode Switching and Coordination: Based on feedback from the dynamic signal quality assessment unit (e.g., signal-to-noise ratio below a first set threshold, or detection of strong pulse interference power exceeding a second set threshold), the control unit commands the multi-mode phase detection unit to switch between two modes. More ingeniously, when switching from high dynamic range mode back to high sensitivity mode, the coarse phase estimate output by the amplitude comparison module can be fed back to the control unit. This allows for rapid resetting of potential phase ambiguity (e.g., 2π integer multiple ambiguity) in the coherent detection module, or initialization of the voltage-controlled oscillator (VCO) frequency of the phase-locked loop, thereby significantly shortening the relocking time and achieving "phase recovery assistance."

[0029] 3. Dynamic signal quality assessment unit.

[0030] This unit consists of a series of analog and digital circuits used to sense the environment of the input radio frequency signal in real time.

[0031] Power monitoring: A small input signal is coupled to a logarithmic detector (such as AD8318) through a directional coupler, and the logarithmic voltage proportional to the input signal power is output in real time.

[0032] Signal-to-noise ratio / interference assessment: After filtering, the signal can be sampled by a high-speed ADC and analyzed in the time and frequency domains by the digital signal processing (DSP) core within the control unit. For example, the peak-to-root mean square (RMS) ratio of the signal is calculated to evaluate impulse characteristics; a fast Fourier transform (FFT) is performed to observe the spectral purity of the signal and detect the presence of in-band spurious signals or interference.

[0033] Output: This unit transmits parameters such as power level, signal-to-noise ratio estimate, and interference flag to the control unit in real time, serving as the core basis for mode switching and parameter adjustment.

[0034] 4. Control unit.

[0035] The control unit is the "brain" of the entire system, and it is preferably implemented by combining a field-programmable gate array (FPGA) or a microprocessor (MCU) with a DSP core.

[0036] Function 1: Coordinated Phase Shifting. It queries a pre-stored "frequency-initial phase shift code" table based on the target frequency and sends a coarse adjustment command to the CNC phase shifter in the first path. Simultaneously, it runs a closed-loop control algorithm (such as a PID algorithm) to calculate the fine adjustment voltage required by the analog phase shifter in the second path based on the error voltage output by the multi-mode phase detector unit, and outputs it through a DAC.

[0037] Function 2: Mode Management. It analyzes data from the dynamic signal quality assessment unit in real time, and based on preset signal-to-noise ratio and transient interference thresholds, decides and sends commands to switch the operating mode of the multi-mode phase detector unit, while simultaneously adjusting relevant parameters (such as the loop bandwidth in the coherent detection module).

[0038] Function 3: Global Scheduling. It is responsible for managing the self-calibration process, accessing the mode memory, processing environmental parameters, starting and stopping the control system health monitoring module, and configuring the filtering algorithm of the intelligent preprocessing interface.

[0039] 5. Intelligent preprocessing interface.

[0040] This interface is located after the analog output of the multimode phase detector unit and typically includes a programmable gain amplifier (PGA) and a digitally controlled filter (such as a switched capacitor-based filter or an FIR / IIR filter implemented directly in the digital domain) configured by the control unit.

[0041] Adaptive filtering: The control unit dynamically selects the filter type (low-pass, band-stop), cutoff frequency, and order based on the current signal quality (such as interference bandwidth) and system operating mode. For example, under strong narrowband interference, it can switch to a notch filter.

[0042] Signal marking and packaging: In the digital domain, this interface adds a "validity" flag to each frame of error voltage data (e.g., determining validity based on signal power and signal-to-noise ratio), performs data compression (e.g., differential coding), and finally outputs the data through communication ports such as SPI, UART, or Ethernet, greatly reducing the processing burden on the back-end main control system.

[0043] 6. Self-calibration module.

[0044] To ensure long-term accuracy, this invention integrates a built-in self-calibration function.

[0045] Hardware components include a miniature, highly stable digitally controlled oscillator (DCO) whose frequency can be precisely stepped within the operating frequency band; a highly isolated microwave switch matrix; and a calibration reference channel that is physically symmetrical to the main signal path.

[0046] Calibration Process: In calibration mode, the control unit controls the switch matrix to simultaneously inject the calibration signal generated by the DCO into the main path and the reference path. The control unit controls the CNC phase shifter of the first path to traverse a series of phase codes (e.g., 0° to 360°, in 5.625° steps), and records the actual output of the multi-mode phase detector unit at each code value. By comparing the "ideal output curve" and the "measured output curve," a "nonlinear error correction table" can be constructed for this specific CNC phase shifter. Simultaneously, by comparing the output differences between the main path and the reference path, the amplitude and phase mismatch between the two channels can be calibrated, and compensation coefficients can be stored. These tables and coefficients will be called by the control unit during normal operation to correct the control codes and output data in real time, thereby offsetting errors caused by device discreteness and temperature drift.

[0047] 7. Environmental parameter sensing module and pattern memory library.

[0048] Environmental sensing: The module includes high-precision temperature sensors (such as PT1000 or digital temperature sensors) mounted on the microwave substrate and heat sink, as well as an optional ambient humidity sensor. They continuously report environmental data to the control unit.

[0049] Memory Bank: The pattern memory bank is a non-volatile memory (such as EEPROM or Flash) that stores the "optimal set of control parameters" calibrated under different temperature-humidity combinations. For example, for the operating condition of "temperature T=25°C, humidity H=30%", the memory bank stores a set of parameters that make the frequency discriminator output most stable and linear, including: the specific bias code of the digitally controlled phase shifter, the initial bias voltage of the analog phase shifter, the optimal loop bandwidth of the coherent detection module in the multi-mode phase discriminator unit, and the default filter coefficients of the intelligent preprocessing interface, etc.

[0050] Rapid initialization: When the system powers on or wakes up, the control unit reads the current environmental parameters, matches the closest set of parameters from the memory bank, or calculates a set of parameters using an interpolation algorithm, and directly loads them into each module. This avoids the system's lengthy self-learning and convergence process, achieving "instantaneous optimal" startup and significantly shortening the stabilization time.

[0051] 8. System health monitoring module.

[0052] This module is used to provide early warnings of potential hardware performance degradation.

[0053] Implementation: Periodically (e.g., every 24 hours) or when the system is idle, the control unit initiates a health check. At this time, the system health monitoring module controls a built-in dual-tone signal source to generate two test tones with a small interval (e.g., 1MHz) and low power (far lower than the operating signal), which are then injected into the radio frequency front end of the frequency discriminator through a coupler.

[0054] Monitoring principle: The system then processes the two test tones as if they were normal signals. The control unit analyzes the spectrum of the final output signal, paying particular attention to the power levels of the third-order intermodulation (IMD3) and fifth-order intermodulation (IMD5) products generated by the nonlinearity of the system's passive components.

[0055] Early warning: By recording and comparing the trend of IMD3 power changes over a long period of time, the risk of deterioration of nonlinear indicators caused by poor connector contact, aging solder joints or degradation of nonlinear characteristics of devices can be detected early and reported in a timely manner to achieve predictive maintenance.

[0056] The working method of this invention (frequency identification and control process).

[0057] Combination Figure 3 The flowchart shown illustrates that the working method of this invention includes the following steps: S1: System Initialization. After power-on, the environmental parameter sensing module acquires information such as current temperature and humidity. The control unit queries the mode memory, loads the corresponding optimal initial control parameter set, and configures each module.

[0058] S2: Signal Reception and Quality Assessment. The input radio frequency signal enters the system. The dynamic signal quality assessment unit continuously analyzes signal power, spectrum, and other characteristics, and reports the assessment results to the control unit.

[0059] S3: Phase coarse adjustment. The control unit calculates the initial phase shift control word required for the first path (CNC phase shift path) based on the target operating frequency (from external commands or internal settings) and issues the command. The CNC phase shifter quickly moves to preset the signal phase to near the linear operating range.

[0060] S4: Phase Locking and Tracking. The control unit enables closed-loop control of the second path (analog phase-shifting path). The multi-mode phase detector unit begins to output an error voltage, which, after being processed by the control algorithm, dynamically adjusts the control voltage of the analog phase shifter to achieve continuous fine-tuning and high-precision locking of the phase. Simultaneously, based on the evaluation results of S2, the control unit decides and switches the operating mode of the multi-mode phase detector unit (high sensitivity / high dynamic range).

[0061] S5: Background Self-Calibration. During periods of stable system operation, the control unit automatically triggers a self-calibration procedure. The miniature DCO generates a calibration signal, and the system iterates through tests and updates the nonlinearity correction table and channel mismatch parameters to ensure measurement accuracy.

[0062] S6: Health Check. At set intervals or when the system is idle, the system health monitoring module is activated to perform a passive intermodulation distortion test and assess the health status of the system hardware.

[0063] S7: Intelligent Output. The locked high-precision error voltage undergoes adaptive filtering, validity marking, and data packaging via the intelligent preprocessing interface, and is finally output to an external Automatic Frequency Control (AFC) system or main controller for adjusting the frequency of the microwave source.

[0064] The broadband phase-shifting frequency discriminator provided by this invention constructs a hierarchical and collaboratively intelligent precision phase detection and control system. Its core lies in the innovative adoption of a hybrid phase-shifting architecture combining "numerical coarse adjustment and analog fine adjustment in parallel," fundamentally resolving the inherent contradiction between speed and accuracy in phase tracking under broadband high-frequency conversion scenarios. This system employs an adaptive closed-loop "perception-decision-execution" mechanism: a dynamic signal quality assessment unit monitors the signal environment in real time, and the control unit intelligently schedules the multi-mode phase discriminator to seamlessly switch between "high sensitivity" and "high dynamic range" modes, while simultaneously adjusting the strategy of the intelligent preprocessing interface, thereby ensuring stability and reliability under complex electromagnetic interference. To further overcome performance drift during long-term operation, this invention integrates a periodic self-calibration module and an environment-aware pre-configuration system (environmental parameter sensing module and mode memory bank), achieving rapid initialization that is "optimal upon power-on" and self-maintaining accuracy throughout its entire lifecycle. Furthermore, the ingenious system health monitoring module, through passive intermodulation distortion analysis, provides early warning of potential hardware performance degradation, upgrading traditional post-fault repair to predictive maintenance.

[0065] Although embodiments of the present invention have been shown and described, these specific embodiments are merely explanations of the invention and are not intended to limit it. The specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. After reading this specification, those skilled in the art may make modifications, substitutions, and variations to the embodiments as needed without departing from the principles and spirit of the invention, but such modifications, substitutions, and variations are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A broadband phase-shifting frequency discriminator, characterized in that, include: Hybrid phase-shifting architecture, multi-mode phase detector unit, dynamic signal quality assessment unit, control unit, and intelligent preprocessing interface; The hybrid phase-shifting architecture includes a first path and a second path arranged in parallel. The first path is a high-precision numerically controlled phase-shifting path, and the second path is a fast continuous analog phase-shifting path. The first path is used to perform coarse phase shifting of the input radio frequency signal by a preset step value according to the instructions of the control unit. The second path is used to perform continuous fine phase shifting of the signal after coarse phase shifting by the first path. The fine-tuning amount is based on the closed-loop control of the real-time output error signal of the frequency discriminator. The multi-mode phase detector unit is connected to the output terminal of the hybrid phase-shifting architecture and is used to perform phase detection processing on the phase-shifted signal and output an error voltage signal. The dynamic signal quality assessment unit is used to monitor the power, signal-to-noise ratio and interference characteristics of the input radio frequency signal in real time. The control unit is communicatively connected to the hybrid phase-shifting architecture, the multi-mode phase detector unit, and the dynamic signal quality assessment unit, respectively, and is used to coordinate and control the coarse phase shift of the first path and the closed-loop fine-tuning of the second path according to the target operating frequency and the signal quality assessment results, and adaptively configure the operating mode of the multi-mode phase detector unit. The intelligent preprocessing interface is connected to the output terminal of the multi-mode phase detector unit and is used to adaptively process the output error voltage signal before outputting it. The control unit is configured to: control the phase shift of the first path according to the target operating frequency, so that the signal phase is preset to a position close to the linear operating point of the frequency discriminator, and start the closed-loop control of the second path to eliminate residual phase error.

2. The broadband phase-shifting frequency discriminator according to claim 1, characterized in that, The multi-mode phase detector unit has at least two phase detection modes, including a high-sensitivity mode and a high-dynamic-range mode. The high-sensitivity mode is suitable for scenarios where the input signal-to-noise ratio is higher than a first set threshold and there is no strong transient interference. It achieves high-precision phase difference detection through a coherent detection module. The high-dynamic-range mode is suitable for scenarios where the input signal-to-noise ratio is lower than the first set threshold or where the detected transient interference power exceeds a second set threshold. It achieves anti-interference phase estimation through an amplitude comparison module. The control unit adaptively switches the operating mode of the multi-mode phase detector unit and configures its parameters according to the output of the dynamic signal quality assessment unit.

3. The broadband phase-shifting frequency discriminator according to claim 2, characterized in that, The multimode phase detection unit includes a coherent detection module based on the phase-locked loop principle and an amplitude comparison module based on envelope detection. In the high-sensitivity mode, the coherent detection module is enabled; In the high dynamic range mode, or when strong transient interference is detected, the amplitude comparison module is activated, and the output of the amplitude comparison module is used to assist the coherent detection module in phase recovery.

4. The broadband phase-shifting frequency discriminator according to claim 1, characterized in that, It also includes a self-calibration module; The self-calibration module includes a micro digitally controlled oscillator, a calibration reference channel, and an internal switching matrix. The internal switch matrix is ​​used to inject the calibration signal generated by the micro digitally controlled oscillator into the input of the hybrid phase-shifting architecture through the calibration reference channel in self-calibration mode. The control unit is also configured to initiate a self-calibration procedure during system idle periods or when performance drift is detected, and to update the nonlinear compensation parameters and channel mismatch parameters of the hybrid phase-shifting architecture in real time by comparing the processing results of the calibration signal in the reference channel and the main signal channel.

5. The broadband phase-shifting frequency discriminator according to claim 1, characterized in that, It also includes an environmental parameter sensing module and a pattern memory library; The environmental parameter sensing module is used to acquire at least one parameter among device temperature, heat sink temperature and ambient humidity. The mode memory is used to store the set of control parameters configured for the hybrid phase-shifting architecture, the multi-mode phase detection unit, and the intelligent preprocessing interface under different combinations of environmental parameters to achieve optimal phase detection performance; The control unit is also configured to: calculate a set of control parameters by matching or interpolating from the mode memory based on the current environmental parameters, and directly apply them to system initialization to shorten the system stabilization time.

6. The broadband phase-shifting frequency discriminator according to claim 1, characterized in that, The intelligent preprocessing interface is configured to perform scene-based adaptive digital filtering, add signal validity flags, and compress data packaging on the raw error voltage signal output by the frequency discriminator. The adaptive digital filtering algorithm and parameters are dynamically adjusted by the control unit based on the results of the dynamic signal quality evaluation unit.

7. The broadband phase-shifting frequency discriminator according to claim 1, characterized in that, It also includes a system health monitoring module; The system health monitoring module is configured to implement passive intermodulation distortion monitoring. It introduces a low-power, two-tone test signal into the radio frequency front end of the frequency discriminator and uses the signal processing resources inside the frequency discriminator to analyze the power of the third-order and fifth-order intermodulation products in the output signal, thereby inferring and reporting the risk of system nonlinear degradation caused by poor connector contact or device aging.

8. A frequency identification and control method for a broadband phase-shift frequency discriminator, applied to the broadband phase-shift frequency discriminator as described in any one of claims 1-7, characterized in that, Includes the following steps: S1: Obtain the current environmental parameters through the environmental parameter sensing module, and load or generate the corresponding optimal initial control parameter set based on the mode memory library to initialize the hybrid phase-shifting architecture, multi-mode phase detection unit and intelligent preprocessing interface; S2: Receives input RF signal, the dynamic signal quality assessment unit analyzes signal characteristics in real time, and the control unit makes decisions and switches the working mode of the multi-mode phase detector unit accordingly. S3: Based on the target frequency, the control unit calculates and executes the coarse phase shift required for the first path, so that the signal enters the predetermined phase working range; S4: Start the closed-loop control of the second path, and continuously fine-tune the phase based on the error signal output in real time by the multi-mode phase detector unit to achieve precise phase tracking and locking. S5: During system operation, periodically or when a sudden change in signal quality is detected by the dynamic signal quality assessment unit, a self-calibration procedure is triggered to update system parameters; S6: The system health monitoring module intermittently checks the nonlinear health status of the system; S7: The intelligent preprocessing interface adaptively processes the final error voltage signal and outputs it for use by the external control system.

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