An x-band noise frequency source with ultra-low phase noise
By combining gallium arsenide avalanche diodes with surface acoustic wave filters in the X-band noise frequency source, introducing a DDS+PLL dual-loop architecture, and combining digital predistortion algorithms and low-temperature coefficient capacitor arrays, the signal conditioning module and intelligent control are optimized. This solves the problems of insufficient phase noise control accuracy and limited frequency conversion flexibility in the existing technology, and achieves high-precision frequency conversion and improved stability in complex environments.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NANJING JULEI ELECTRONIC TECH CO LTD
- Filing Date
- 2025-09-03
- Publication Date
- 2026-07-14
AI Technical Summary
Existing X-band noise frequency sources suffer from insufficient phase noise control precision, limited frequency conversion flexibility, weak environmental adaptability, and limited signal purity optimization methods, resulting in output signals that are difficult to meet the requirements of high-precision radar systems. Furthermore, there is room for improvement in their operational stability and signal adjustment range under complex environments.
An ultra-low phase noise baseband signal is generated by combining gallium arsenide avalanche diodes and surface acoustic wave filters. A DDS+PLL dual-loop architecture is introduced to achieve high-precision frequency conversion. A digital predistortion algorithm and a low-temperature coefficient capacitor array are combined to suppress carrier phase noise. A variable gain amplifier and a directional coupler are integrated to optimize the signal dynamic range. An intelligent control module is used to improve environmental adaptability.
It significantly reduces the phase noise floor, achieves high-precision frequency conversion in 0.1Hz steps, systematically suppresses near-end phase noise of the carrier, expands the dynamic range of the signal, and improves the working stability and signal purity of the frequency source in complex environments, meeting the requirements of high-precision, high-stability, and high-security clock signals.
Smart Images
Figure CN224503352U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of microwave frequency source technology, and in particular to an X-band noise frequency source with ultra-low phase noise. Background Technology
[0002] In microwave systems such as radar, communication, and electronic countermeasures, the frequency source is the core component of the system, and its performance directly affects the performance indicators of the entire system. X-band frequency sources have attracted much attention due to their important applications in radar, satellite communication and other fields. Phase noise is one of the key indicators for measuring the performance of frequency sources. Lower phase noise can improve the signal-to-noise ratio of the system, reduce the bit error rate, and improve ranging accuracy.
[0003] Existing X-band noise frequency sources suffer from technical shortcomings such as insufficient phase noise control precision, limited frequency conversion flexibility, weak environmental adaptability, and limited signal purity optimization methods. Traditional designs lack systematic optimization in noise source generation, frequency synthesis, and phase noise suppression, resulting in output signal phase noise indicators that are difficult to meet the requirements of high-precision radar systems. Furthermore, there is room for improvement in terms of operational stability and signal adjustment range in complex environments.
[0004] To address the shortcomings of existing X-band noise frequency sources, such as insufficient phase noise control precision, limited frequency conversion flexibility, weak environmental adaptability, and limited signal purity optimization methods, traditional designs lack systematic optimization in noise source generation, frequency synthesis, and phase noise suppression. This results in output signal phase noise performance failing to meet the requirements of high-precision radar systems, and room for improvement in operational stability and signal adjustment range under complex environments. This solution significantly reduces the phase noise floor of the original noise by employing a combination of gallium arsenide avalanche diodes and surface acoustic wave filters in the noise source module; frequency synthesis… The modular design incorporates a DDS+PLL dual-loop architecture to achieve high-precision frequency conversion in 0.1Hz steps. The phase noise optimization module systematically suppresses near-end phase noise of the carrier through the synergistic effect of a digital predistortion algorithm and a low-temperature coefficient capacitor array. The signal conditioning module integrates a variable gain amplifier and a directional coupler to expand the dynamic range and optimize impedance matching. The intelligent control module uses PID algorithms and temperature compensation technology to improve environmental adaptability, resulting in significant improvements in phase noise performance, frequency switching speed, environmental adaptability, and signal purity of the frequency source, effectively meeting the requirements for high-precision, high-stability, and high-security clock signals. Utility Model Content
[0005] To overcome the shortcomings of existing X-band noise frequency sources in terms of insufficient phase noise control precision, limited frequency conversion flexibility, weak environmental adaptability, and limited signal purity optimization methods, traditional designs lack systematic optimization in noise source generation, frequency synthesis, and phase noise suppression. This results in the phase noise performance of the output signal failing to meet the requirements of high-precision radar systems, and there is room for improvement in terms of operational stability and signal adjustment range in complex environments.
[0006] The technical solution of this utility model is: an X-band noise frequency source with ultra-low phase noise, comprising a frequency source housing, the frequency source housing integrating the following modules:
[0007] Noise source module: Used to generate a baseband signal with ultra-low phase noise, serving as the raw signal source for the frequency source;
[0008] Frequency synthesis module: used for precise frequency conversion and output of noise signals;
[0009] Phase noise optimization module: Used to systematically reduce carrier phase noise and improve signal purity;
[0010] Signal conditioning module: used to optimize signal power and impedance matching to adapt to different load requirements;
[0011] Intelligent control module: used to realize adaptive adjustment of system parameters and health management.
[0012] Preferably, the noise source module is configured with a microwave noise diode, a low-noise amplifier, and a surface acoustic wave filter. Its function is to generate a broadband white noise signal, which, after amplification and filtering, forms an ultra-low phase noise baseband signal, providing the original frequency resources for the frequency source. The noise source module includes:
[0013] A microwave noise diode unit, comprising a gallium arsenide avalanche diode chip, a ceramic package, a bias inductor, and a decoupling capacitor, is used to generate broadband white noise through the avalanche effect;
[0014] The output of the noise amplifier unit is connected to the input of the noise amplifier unit via a 50Ω microstrip line. It includes an HMC626LP4 chip, an input matching network, and an output matching network, and is used to boost weak noise signals to a processable level.
[0015] The surface acoustic wave (SAW) filter unit, whose output terminal is connected to the input terminal of the noise amplifier unit via bonding wires, includes a LiNbO3 piezoelectric substrate, interdigital transducers, and absorbing materials, and is used to suppress out-of-band noise and retain the effective components of the X-band.
[0016] Preferably, the frequency synthesis module integrates a phase-locked loop chip, a direct digital synthesizer, and a high-isolation mixer. It achieves precise frequency conversion of noise signals through a dual-loop architecture, supports 0.1Hz step adjustment, and outputs X-band signals covering 8-12GHz. The frequency synthesis module includes:
[0017] The phase-locked loop unit, including the HMC704LP4 chip, a third-order loop filter, and a VCO, is used to provide a highly stable reference frequency.
[0018] The direct digital synthesizer unit, including the AD9914 chip, clock buffer, and elliptic low-pass filter, is used to generate programmable arbitrary waveforms.
[0019] The mixer unit, including the HMC553MS8G chip, local oscillator driver, and RF / IF isolator, is used to perform upconversion processing.
[0020] Preferably, the phase noise optimization module includes a digital predistortion correction unit, a low-temperature coefficient capacitor array, and a dynamic feedback compensation loop. It employs a cubic spline interpolation algorithm to perform real-time compensation of the signal phase, systematically reducing near-end phase noise of the carrier wave, with a typical performance of -135dBc / Hz@10kHz. The phase noise optimization module also includes:
[0021] The phase correction unit, including a Xilinx Spartan-6 FPGA, ADC, and DAC, is used to compensate for nonlinear distortion using digital predistortion techniques.
[0022] A low-temperature coefficient capacitor array, including C0G dielectric capacitors, ADG1208 switch matrix and AD7414 temperature sensor, is used to stabilize the load characteristics of the frequency source.
[0023] The feedback compensation loop, including an OPA695 operational amplifier, a third-order Butterworth filter, and a PID controller, is used to dynamically adjust the loop bandwidth.
[0024] Preferably, the signal conditioning module consists of a variable gain amplifier, a directional coupler, and an impedance matching network, enabling dynamic adjustment of the output power from -20dBm to +10dBm. It also ensures impedance matching with the load through a 50Ω microstrip line structure, achieving a return loss better than -15dB. The signal conditioning module includes:
[0025] The variable gain amplifier unit, including the HMC626LP4 chip, PIN diode attenuation network and driver amplifier, is used to achieve a dynamic range adjustment from -10dB to +20dB.
[0026] The directional coupler unit, including a microstrip line coupling structure, isolation resistor, and SMA connector, is used for real-time monitoring of forward / reverse power;
[0027] Impedance matching network elements, including λ / 4 microstrip lines, matching capacitors, and an array of ground vias, are used to ensure a 50Ω standard impedance.
[0028] Preferably, the intelligent control module uses an ARM controller as its core, integrating a high-precision temperature sensor and non-volatile memory. It dynamically adjusts system parameters through a PID algorithm, collects temperature data from key nodes in real time, and stores calibration information to ensure environmental adaptability. The intelligent control module includes:
[0029] The ARM control unit, including an STM32F407ZGT6 chip, a 16MHz crystal oscillator, and a JTAG debugging interface, is used to execute adaptive control algorithms.
[0030] The temperature monitoring unit, including an AD7414 sensor, a 0.1μF filter capacitor, and a pull-up resistor, is used to monitor the temperature of critical nodes in real time.
[0031] The data storage unit, including a 24LC256 EEPROM, a 0.1μF decoupling capacitor, and a write protection pin, is used to store calibration data and fault logs.
[0032] Preferably, an upper cover plate is provided on the top of the frequency source box, and a lower cover plate is provided on the bottom of the frequency source box. Both the upper and lower cover plates have mounting holes for connecting the frequency source box.
[0033] The beneficial effects of this utility model are:
[0034] Existing X-band noise frequency sources suffer from drawbacks in technical implementation, including insufficient phase noise control precision, limited frequency conversion flexibility, weak environmental adaptability, and limited signal purity optimization methods. Traditional designs lack systematic optimization in noise source generation, frequency synthesis, and phase noise suppression, resulting in output signal phase noise performance that fails to meet the requirements of high-precision radar systems. Furthermore, there is room for improvement in operational stability and signal adjustment range under complex environments. This solution significantly reduces the phase noise floor of the original noise by employing a combination of gallium arsenide avalanche diodes and surface acoustic wave filters in the noise source module; the frequency synthesis module… A DDS+PLL dual-loop architecture is introduced to achieve high-precision frequency conversion in 0.1Hz steps; the phase noise optimization module systematically suppresses near-end phase noise of the carrier through the synergistic effect of digital predistortion algorithm and low-temperature coefficient capacitor array; the signal conditioning module integrates a variable gain amplifier and a directional coupler to expand the dynamic range and optimize impedance matching; the intelligent control module uses PID algorithm and temperature compensation technology to improve environmental adaptability, resulting in significant improvements in phase noise performance, frequency switching speed, environmental adaptability, and signal purity of the frequency source, effectively meeting the requirements for high-precision, high-stability, and high-security clock signals. Attached Figure Description
[0035] Figure 1 The diagram shown is a schematic of the X-band noise frequency source frame with ultra-low phase noise according to this utility model.
[0036] Figure 2 The diagram shown is a first three-dimensional structural schematic of an X-band noise frequency source with ultra-low phase noise according to this utility model.
[0037] Figure 3 The diagram shown is a second three-dimensional structural schematic of an X-band noise frequency source with ultra-low phase noise according to this utility model.
[0038] Explanation of reference numerals in the attached diagram: 1. Frequency source housing; 2. Upper cover plate; 3. Lower cover plate; 4. Mounting hole. Detailed Implementation
[0039] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0040] Please see Figure 1 This utility model provides an embodiment: an X-band noise frequency source with ultra-low phase noise, including a frequency source housing 1, which integrates the following modules:
[0041] Noise source module: Used to generate a baseband signal with ultra-low phase noise, serving as the raw signal source for the frequency source;
[0042] Frequency synthesis module: used for precise frequency conversion and output of noise signals;
[0043] Phase noise optimization module: Used to systematically reduce carrier phase noise and improve signal purity;
[0044] Signal conditioning module: used to optimize signal power and impedance matching to adapt to different load requirements;
[0045] Intelligent control module: used to realize adaptive adjustment of system parameters and health management.
[0046] Preferably, the noise source module is configured with a microwave noise diode, a low-noise amplifier, and a surface acoustic wave filter. Its function is to generate a broadband white noise signal, which, after amplification and filtering, forms an ultra-low phase noise baseband signal, providing the original frequency resources for the frequency source. The noise source module includes:
[0047] A microwave noise diode unit, comprising a gallium arsenide avalanche diode chip, a ceramic package, a bias inductor, and a decoupling capacitor, is used to generate broadband white noise through the avalanche effect;
[0048] The output of the noise amplifier unit is connected to the input of the noise amplifier unit via a 50Ω microstrip line. It includes an HMC626LP4 chip, an input matching network, and an output matching network, and is used to boost weak noise signals to a processable level.
[0049] The surface acoustic wave (SAW) filter unit, whose output terminal is connected to the input terminal of the noise amplifier unit via bonding wires, includes a LiNbO3 piezoelectric substrate, interdigital transducers, and absorbing materials, and is used to suppress out-of-band noise and retain the effective components of the X-band.
[0050] Preferably, the frequency synthesis module integrates a phase-locked loop chip, a direct digital synthesizer, and a high-isolation mixer. It achieves precise frequency conversion of noise signals through a dual-loop architecture, supports 0.1Hz step adjustment, and outputs X-band signals covering 8-12GHz. The frequency synthesis module includes:
[0051] The phase-locked loop unit, including the HMC704LP4 chip, a third-order loop filter, and a VCO, is used to provide a highly stable reference frequency.
[0052] The direct digital synthesizer unit, including the AD9914 chip, clock buffer, and elliptic low-pass filter, is used to generate programmable arbitrary waveforms.
[0053] The mixer unit, including the HMC553MS8G chip, local oscillator driver, and RF / IF isolator, is used to perform upconversion processing.
[0054] Preferably, the phase noise optimization module includes a digital predistortion correction unit, a low-temperature coefficient capacitor array, and a dynamic feedback compensation loop. It employs a cubic spline interpolation algorithm to perform real-time compensation of the signal phase, systematically reducing near-end phase noise of the carrier wave, with a typical performance of -135dBc / Hz@10kHz. The phase noise optimization module also includes:
[0055] The phase correction unit, including a Xilinx Spartan-6 FPGA, ADC, and DAC, is used to compensate for nonlinear distortion using digital predistortion techniques.
[0056] A low-temperature coefficient capacitor array, including C0G dielectric capacitors, ADG1208 switch matrix and AD7414 temperature sensor, is used to stabilize the load characteristics of the frequency source.
[0057] The feedback compensation loop, including an OPA695 operational amplifier, a third-order Butterworth filter, and a PID controller, is used to dynamically adjust the loop bandwidth.
[0058] Preferably, the signal conditioning module consists of a variable gain amplifier, a directional coupler, and an impedance matching network, enabling dynamic adjustment of the output power from -20dBm to +10dBm. It also ensures impedance matching with the load through a 50Ω microstrip line structure, achieving a return loss better than -15dB. The signal conditioning module includes:
[0059] The variable gain amplifier unit, including the HMC626LP4 chip, PIN diode attenuation network and driver amplifier, is used to achieve a dynamic range adjustment from -10dB to +20dB.
[0060] The directional coupler unit, including a microstrip line coupling structure, isolation resistor, and SMA connector, is used for real-time monitoring of forward / reverse power;
[0061] Impedance matching network elements, including λ / 4 microstrip lines, matching capacitors, and an array of ground vias, are used to ensure a 50Ω standard impedance.
[0062] Preferably, the intelligent control module uses an ARM controller as its core, integrating a high-precision temperature sensor and non-volatile memory. It dynamically adjusts system parameters through a PID algorithm, collects temperature data from key nodes in real time, and stores calibration information to ensure environmental adaptability. The intelligent control module includes:
[0063] The ARM control unit, including an STM32F407ZGT6 chip, a 16MHz crystal oscillator, and a JTAG debugging interface, is used to execute adaptive control algorithms.
[0064] The temperature monitoring unit, including an AD7414 sensor, a 0.1μF filter capacitor, and a pull-up resistor, is used to monitor the temperature of critical nodes in real time.
[0065] The data storage unit, including a 24LC256 EEPROM, a 0.1μF decoupling capacitor, and a write protection pin, is used to store calibration data and fault logs.
[0066] Please see Figure 2-3 In this embodiment, an upper cover plate 2 is provided above the frequency source box 1, and a lower cover plate 3 is provided below the frequency source box 1. Both the upper cover plate 2 and the lower cover plate 3 have mounting holes 4 for connecting the frequency source box 1.
[0067] During operation, the microwave noise diode generates broadband white noise through the avalanche effect, which is then amplified by low noise and filtered by surface acoustic waves to form an ultra-low phase noise baseband signal. The frequency synthesis module uses a dual-loop architecture of phase-locked loop and direct digital synthesizer to accurately upconvert the baseband signal to 8-12GHz and perform 0.1Hz step adjustment. The phase noise optimization module uses digital predistortion technology to compensate for nonlinear distortion, combined with a low-temperature coefficient capacitor array and dynamic feedback loop, to systematically reduce the near-end phase noise of the carrier to -135dBc / Hz@10kHz. The signal conditioning module achieves dynamic adjustment of output power through a variable gain amplifier and directional coupler, and ensures a standard output of 50Ω through an impedance matching network. The intelligent control module collects temperature data in real time and executes a PID algorithm to dynamically adjust the gain of the capacitor array and amplifier. All modules are cascaded with RF probes through a high-speed digital bus to form a closed-loop control system, ensuring ultra-low phase noise characteristics and a frequency switching speed of <50μs in an environment of -40℃ to +85℃.
[0068] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.
Claims
1. An X-band noise frequency source with ultra-low phase noise, comprising a frequency source housing (1), characterized in that: The frequency source housing (1) integrates the following modules: Noise source module: Used to generate a baseband signal with ultra-low phase noise, serving as the raw signal source for the frequency source; Frequency synthesis module: used for precise frequency conversion and output of noise signals; Phase noise optimization module: Used to systematically reduce carrier phase noise and improve signal purity; Signal conditioning module: used to optimize signal power and impedance matching to adapt to different load requirements; Intelligent control module: used to realize adaptive adjustment of system parameters and health management.
2. The X-band noise frequency source with ultra-low phase noise according to claim 1, characterized in that: The noise source module consists of a microwave noise diode, a low-noise amplifier, and a surface acoustic wave filter. The noise source module also includes: The microwave noise diode unit includes a gallium arsenide avalanche diode chip, a ceramic package, a bias inductor, and a decoupling capacitor; The noise amplifier unit, whose output terminal is connected to the input terminal of the noise amplifier unit via a 50Ω microstrip line, includes an HMC626LP4 chip, an input matching network, and an output matching network; The surface acoustic wave (SAW) filter unit, whose output terminal is connected to the input terminal of the noise amplifier unit via bonding wires, includes a LiNbO3 piezoelectric substrate, an interdigital transducer, and an absorbing material.
3. The X-band noise frequency source with ultra-low phase noise according to claim 1, characterized in that: The frequency synthesis module integrates a phase-locked loop chip, a direct digital synthesizer, and a high-isolation mixer. The frequency synthesis module also includes: The phase-locked loop unit includes an HMC704LP4 chip, a third-order loop filter, and a VCO; The direct digital synthesizer unit includes an AD9914 chip, a clock buffer, and an elliptic low-pass filter; The mixer unit includes an HMC553MS8G chip, a local oscillator driver, and an RF / IF isolator.
4. The X-band noise frequency source with ultra-low phase noise according to claim 1, characterized in that: The phase noise optimization module includes a digital predistortion correction unit, a low-temperature coefficient capacitor array, and a dynamic feedback compensation loop. It uses a cubic spline interpolation algorithm to perform real-time compensation for the signal phase. The phase noise optimization module also includes: Phase correction unit, including Xilinx Spartan-6 FPGA, ADC and DAC; Low-temperature coefficient capacitor array, including C0G dielectric capacitors, ADG1208 switch matrix and AD7414 temperature sensor; The feedback compensation loop includes an OPA695 operational amplifier, a third-order Butterworth filter, and a PID controller.
5. The X-band noise frequency source with ultra-low phase noise according to claim 1, characterized in that: The signal conditioning module consists of a variable gain amplifier, a directional coupler, and an impedance matching network. The signal conditioning module also includes: The variable gain amplifier unit includes an HMC626LP4 chip, a PIN diode attenuation network, and a driver amplifier; The directional coupler unit includes a microstrip line coupling structure, an isolation resistor, and an SMA connector; Impedance matching network unit, including λ / 4 microstrip line, matching capacitor and ground via array.
6. The X-band noise frequency source with ultra-low phase noise according to claim 1, characterized in that: The intelligent control module is based on an ARM controller and integrates a high-precision temperature sensor and non-volatile memory. The intelligent control module also includes: The ARM control unit includes an STM32F407ZGT6 chip, a 16MHz crystal oscillator, and a JTAG debugging interface; The temperature monitoring unit includes an AD7414 sensor, a 0.1μF filter capacitor, and a pull-up resistor; The data storage unit includes a 24LC256 EEPROM, a 0.1μF decoupling capacitor, and a write protection pin.
7. The X-band noise frequency source with ultra-low phase noise according to claim 1, characterized in that: A top cover plate (2) is provided on the upper part of the frequency source box (1), and a bottom cover plate (3) is provided on the lower part of the frequency source box (1). Mounting holes (4) for connecting the frequency source box (1) are provided on the surfaces of both the top cover plate (2) and the bottom cover plate (3).