Simple and practical polarization agility signal generation circuit

Abstract

The invention relates to the technical field of navigation countermeasure, in particular to a simple and practical polarization agility signal generation circuit which comprises a radio frequency switch control module, a rectangular wave signal generator module and a dual-polarization four-ridge horn antenna module. The radio frequency switch is driven by the rectangular wave signal to switch an output path, the dual-polarized antenna is controlled to alternately transmit horizontal and vertical polarized signals, and rapid time domain change of spatial polarization is realized. The system supports frequency and duty ratio adjustment, integrates functional modules of filtering shaping, power detection, remote control and automatic calibration, and has the advantages of high polarization switching speed, compact structure, flexible parameters and high stability. The method can be widely applied to the fields of navigation interference test, radar countermeasure and communication system evaluation, and has good engineering practicability and popularization value.

Description

Technical Field

[0001] This invention relates to the field of navigation countermeasures technology, and more specifically, to a simple and practical polarization agile signal generation circuit. Background Technology

[0002] Antenna polarization is a crucial parameter describing the spatial orientation of the electric field vector of its radiated electromagnetic waves, playing a key role in wireless communication, radar detection, and electronic warfare. Linear polarization, a common form of polarization, maintains a constant electric field direction during propagation; typical forms include horizontal and vertical polarization. Maximum energy reception is achieved when the polarization direction of the receiving antenna aligns with the incident electromagnetic wave; conversely, if the polarization directions are orthogonal, the received energy is almost zero, resulting in significant polarization mismatch loss.

[0003] In the fields of radar and electronic warfare, polarization domain countermeasures have gradually become an important means of improving jamming effectiveness. Studies have shown that cross-polarization jamming can effectively deplete the degrees of freedom of the adaptive sidelobe cancellation system of phased array radar, reducing its anti-jamming capability. However, in the field of navigation countermeasures, although its technical principles are highly similar to those of radar and communications, current jamming equipment is still mainly limited to jamming methods in the airspace and energy domains, lacking effective utilization of the polarization domain.

[0004] With the widespread application of multi-element adaptive nulling antennas in navigation equipment, traditional fixed-polarization jamming methods are insufficient to effectively suppress them. Research shows that polarization-agile jamming can occupy multiple spatial degrees of freedom without increasing the number of interference sources, significantly weakening the performance of anti-jamming antennas. Therefore, we propose a simple and practical polarization-agile signal generation circuit. Summary of the Invention

[0005] The purpose of this invention is to address the problems raised in the existing background technology. To achieve the above-mentioned objective, this invention provides the following technical solution: a simple and practical polarization agile signal generation circuit, including an RF switch control module, a rectangular wave signal generator module, a dual-polarized four-ridged horn antenna module, and a signal source switching control module. The input terminal of the RF switch control module is connected to an interference signal source; the RF switch control module includes a single-pole double-throw RF switch, and its output terminal is respectively connected to the two orthogonal polarization input ports of the dual-polarized four-ridged horn antenna module; the PWM output terminal of the rectangular wave signal generator module is connected to the control terminal "Vctl" of the RF switch control module, used to control the switching of the RF switch between the two outputs.

[0006] As a preferred technical solution of the present invention, the radio frequency switch control module adopts a radio frequency switch device of model 349LP4C, with an operating frequency range of 0.1GHz to 6.0GHz and a power supply voltage of 3.3 to 5V. When the control voltage is high (2 to 5V), the first output terminal "RF1" is turned on and the second output terminal "RF2" is turned off; when the control voltage is low (0 to 0.8V), the second output terminal "RF2" is turned on and the first output terminal "RF1" is turned off.

[0007] As a preferred embodiment of the present invention, the rectangular wave signal generator module includes a programmable controller unit, a key input unit, and an EEPROM storage unit. The programmable controller unit generates a square wave signal through an internal timer. The key input unit includes four independent buttons: “FREQ+”, “FREQ−”, “DUTY+”, and “DUTY−”, supporting short press (increase or decrease by one unit) and long press (rapid increase or decrease) operation modes. The EEPROM storage unit is used to save the currently set frequency and duty cycle parameters, and the settings are not lost after power failure.

[0008] As a preferred technical solution of the present invention, the frequency of the square wave signal output by the rectangular wave signal generator module is adjustable in the range of 1Hz to 150kHz, the duty cycle is adjusted in 1% increments between 10% and 90%, the output amplitude is equal to the power supply voltage, and the output current is 5 to 30mA.

[0009] As a preferred technical solution of the present invention, the dual-polarized quad-ridged horn antenna module covers a frequency range of 1 to 2 GHz, includes two independent feed channels of horizontal polarization and vertical polarization, each channel is provided with an N-type connector, the polarization isolation is not less than 20 dB, and the standing wave ratio is not greater than 2.5.

[0010] As a preferred technical solution of the present invention, it also includes an antenna angle adjustment bracket module for mounting the dual-polarized four-ridged horn antenna module and allowing it to rotate ±30° in the horizontal plane and pitch ±15° in the vertical plane.

[0011] As a preferred technical solution of the present invention, the radio frequency switch control module can be replaced with a single-pole multi-throw radio frequency switch structure, with its multiple output terminals connected to different polarization input ports of multiple dual-polarized horn antennas, enabling rapid switching between horizontal polarization, vertical polarization and slant polarization.

[0012] As a preferred technical solution of the present invention, it also includes a remote control interface module, which is connected to the rectangular wave signal generator module via UART or I²C communication protocol, for receiving frequency and duty cycle configuration commands sent by external control devices and updating the current operating parameters.

[0013] As a preferred technical solution of the present invention, the rectangular wave signal generator module has a built-in regulated power supply management unit with an input voltage range of 3.3V to 30V and an output PWM amplitude equal to the power supply voltage, which is beneficial to achieve matching with the "Vctl" voltage of the control terminal of the radio frequency switch module (101).

[0014] As a preferred embodiment of the present invention, it further includes a status indication module, an RF power detection module, a filtering and shaping module, a signal source switching module, an automatic calibration module, and a local display and interaction module. The status indication module consists of LED indicators, used to indicate the current conduction path of the RF switch, the operating status of the rectangular wave signal generator, and the system power supply status. The RF power detection module is integrated into the output path of the RF switch control module, used to monitor the power intensity of each output RF signal in real time and feed the detection results back to the main control unit or an external display device. The filtering and shaping module is located at the output end of the rectangular wave signal generator module and the RF switch control module. Between the blocks, filtering and edge shaping of the square wave signal are performed to improve the stability and anti-interference capability of the control signal; the signal source switching module is located between the interference signal source and the RF switch control module to select different types of interference signal sources, including CW continuous wave signal source, LFM linear frequency modulation signal source or multi-tone interference signal source; the automatic calibration module is used to periodically perform self-checks and error compensation on the RF switch control logic, rectangular wave output accuracy and antenna polarization matching status to ensure the long-term stability of the system; the local display and interaction module integrates an OLED display screen and a rotary encoder to display the current frequency, duty cycle and polarization status information in real time.

[0015] Compared with existing technologies, the beneficial effects of this invention are as follows: The rectangular wave signal generator module of this invention can generate rectangular wave signals with a frequency range of 1kHz to 100kHz and an adjustable duty cycle range of 10% to 90%. By adjusting the frequency and duty cycle of the rectangular wave signal, the switching frequency and time ratio of the RF switch module can be precisely controlled, thereby flexibly changing the polarization agility rate and the duration ratio of dual polarization to meet the diverse requirements of polarization agility rate in different application scenarios. For example, in the field of electronic countermeasures, the polarization agility rate can be quickly adjusted according to the characteristics of the jamming target to improve the jamming effect.

[0016] The RF switch module is equipped with a temperature compensation circuit, which ensures stable switching performance within a temperature range of -40°C to 85°C. The insertion loss of the switch fluctuates by less than ±0.5dB with temperature changes, and the switching time is less than 100ns, effectively avoiding the impact of ambient temperature changes on the switching performance and ensuring reliable operation of the circuit in different temperature environments.

[0017] High isolation antenna reduces interference: The polarization isolation of the dual-polarized four-ridged horn antenna is greater than 20dB, which can effectively reduce mutual interference between the two polarization ports. The antenna gain is greater than 10dBi, which can radiate signals with high efficiency, ensuring accurate transmission and reception of polarization-agile signals and improving the performance stability of the entire circuit system.

[0018] The circuit adopts a modular design, with the RF switch module, rectangular wave signal generator module, and low-noise amplifier module having clearly defined functions and interfaces, facilitating integration and assembly. This approach not only reduces circuit complexity but also improves production efficiency, which is beneficial for large-scale production and application.

[0019] The passband frequency range of the bandpass filter module can be set within 1GHz-10GHz according to actual needs. It is implemented using a microstrip line structure, and the filter order is 3-7, which can be selected according to different passband frequencies and out-of-band suppression requirements. This allows the circuit to process signals with a wide bandwidth and adapt to the application needs of different frequency bands, including communications, radar, and electronic warfare fields.

[0020] The monitoring module can monitor the circuit's operating status in real time, including switching status, amplifier gain, and power parameters, and upload the monitoring data to external devices via a communication interface. Users can adjust circuit parameters promptly based on the monitoring data, enabling remote control and management of the circuit, thus improving its application adaptability and intelligence. Attached Figure Description

[0021] Figure 1 The polarization agile circuit composition and schematic diagram provided by this invention; Figure 2 This is a schematic diagram of the navigation interference application of the polarization agile circuit provided by the present invention; Figure 3 The polarization agile circuit navigation interference signal power calibration diagram provided by this invention; Figure 4 A schematic block diagram of the parameters of the radio frequency switch module provided by the present invention; Figure 5 A schematic block diagram of the rectangular wave signal generator module parameters provided by the present invention; Figure 6 A schematic diagram of the polarization switching control logic provided by the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0023] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely illustrates some embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. It should be noted that, in the absence of conflict, the embodiments and features and technical solutions in the embodiments of the present invention can be combined with each other. It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0024] Example 1: A simple and practical polarization agile signal generation circuit. This circuit includes an RF switch control module 101, a rectangular wave signal generator module 102, a dual-polarized four-ridged horn antenna module 103, and a signal source switching control module 104. The input terminal of the RF switch control module 101 is connected to an interference signal source. The RF switch control module 101 includes a single-pole double-throw RF switch, and its output terminal is connected to the two orthogonal polarization input ports of the dual-polarized four-ridged horn antenna module 103. The PWM output terminal of the rectangular wave signal generator module 102 is connected to the control terminal "Vctl" of the RF switch control module 101 to control the switching of the RF switch between the two outputs.

[0025] The RF switch control module 101 uses an RF switch device of model 349LP4C, with an operating frequency range of 0.1GHz to 6.0GHz and a power supply voltage of 3.3 to 5V. When the control voltage is high (2 to 5V), the first output terminal "RF1" is turned on and the second output terminal "RF2" is turned off; when the control voltage is low (0 to 0.8V), the second output terminal "RF2" is turned on and the first output terminal "RF1" is turned off.

[0026] The rectangular wave signal generator module 102 includes a programmable controller unit, a key input unit, and an EEPROM storage unit. The programmable controller unit generates square wave signals through an internal timer. The key input unit includes four independent buttons: “FREQ+”, “FREQ−”, “DUTY+”, and “DUTY−”, which support short press (increase or decrease by one unit) and long press (rapid increase or decrease) operation modes. The EEPROM storage unit is used to save the currently set frequency and duty cycle parameters, and the settings are not lost after power failure.

[0027] The square wave signal output by the rectangular wave signal generator module 102 has an adjustable frequency range of 1Hz to 150kHz, an adjustable duty cycle of 1% to 90% in 1% increments, an output amplitude equal to the power supply voltage, and an output current of 5 to 30mA.

[0028] The dual-polarized quad-ridge horn antenna module 103 covers a frequency range of 1 to 2 GHz and includes two independent feed channels for horizontal and vertical polarization. Each channel is equipped with an N-type connector, with a polarization isolation of not less than 20 dB and a standing wave ratio of not more than 2.5.

[0029] It also includes an antenna angle adjustment bracket module for mounting the dual-polarized quad-ridge horn antenna module 103 and allowing it to rotate ±30° in the horizontal plane and pitch ±15° in the vertical plane.

[0030] The RF switch control module 101 can be replaced with a single-pole multi-throw RF switch structure, with its multiple output terminals connected to different polarization input ports of multiple dual-polarized horn antennas, enabling rapid switching between horizontal polarization, vertical polarization and slant polarization.

[0031] It also includes a remote control interface module, which is connected to the rectangular wave signal generator module 102 via UART or I²C communication protocol. This module is used to receive frequency and duty cycle configuration commands sent by external control devices and update the current operating parameters.

[0032] The rectangular wave signal generator module 102 has a built-in regulated power management unit with an input voltage range of 3.3V to 30V. The output PWM amplitude is equal to the supply voltage, which is beneficial for matching with the "Vctl" voltage at the control terminal of the RF switch module 101.

[0033] This invention also includes a status indication module, an RF power detection module, a filtering and shaping module, a signal source switching module, an automatic calibration module, and a local display and interaction module. The status indication module consists of LED indicators, used to indicate the current conduction path of the RF switch, the operating status of the rectangular wave signal generator, and the system power supply status. The RF power detection module is integrated into the output path of the RF switch control module 101, used to monitor the power intensity of each output RF signal in real time and feed the detection results back to the main control unit or an external display device. The filtering and shaping module is located between the output end of the rectangular wave signal generator module 102 and the RF switch control module 101, used to filter the square wave signal and... Edge shaping is performed to improve the stability and anti-interference capability of the control signal; the signal source switching module 104 is located between the interference signal source and the RF switch control module 101 to select different types of interference signal sources, including CW continuous wave signal source, LFM linear frequency modulation signal source or multi-tone interference signal source; the automatic calibration module is used to periodically perform self-checks and error compensation on the RF switch control logic, rectangular wave output accuracy and antenna polarization matching status to ensure the long-term stability of the system; the local display and interaction module integrates an OLED display screen and a rotary encoder to display the current frequency, duty cycle and polarization status information in real time, and supports users to manually input parameters for instant adjustment.

[0034] Example 2: A simple and practical polarization-agile signal generation circuit. Step 1: Connection of the polarization-agile circuit: Connect the output terminal of the interference signal source to the input port IN of the RF switch control module 101 in the polarization-agile circuit via an RF connection cable. The RF switch adopts a single-pole double-throw structure of model 349LP4C, and its two output terminals RF1 and RF2 are respectively connected to the horizontal polarization input port and vertical polarization input port of the dual-polarization four-ridge horn antenna module 103. The control terminal "Vctl" of the RF switch is connected to the PWM output terminal of the rectangular wave signal generator module 102 to control the switching of the RF signal between the two polarization channels.

[0035] The rectangular wave signal generator module is composed of an STM32F103 series microcontroller, which has a frequency adjustment range of 1Hz to 150kHz and a duty cycle adjustment range of 10% to 90%. The output signal is edge-optimized by a filter and shaping circuit module to improve control stability.

[0036] Step Two: Adjusting the Polarization Agility Rate: After the polarization agility circuit is correctly connected and powered on, it enters normal operating mode. Users can adjust the output frequency of the PWM signal using the FREQ "+" and FREQ "-" buttons on the rectangular wave signal generator module, thereby changing the switching frequency of the RF switch and achieving continuous adjustment of the polarization switching rate.

[0037] Meanwhile, the duty cycle of the PWM signal can be adjusted using the DUTY "+" and DUTY "-" buttons, thereby controlling the distribution ratio of the two polarization states on the time axis. For example, when the duty cycle is set to 50%, the system alternates between horizontal and vertical polarization for a longer duration; if set to 70%, the horizontal polarization duration is longer, which can be used to simulate asymmetric polarization interference scenarios.

[0038] The adjustment results can be displayed in real time on the local OLED display and saved to EEPROM for use on the next startup.

[0039] Step 3: Testing the Interference Effect of Polarization Agility Signals: Constructing a navigation interference test environment, such as... Figure 2 As shown. This polarization agile signal generating device and the interference signal source, including a standard CW signal source, output a GPS L1 frequency (1575.42MHz) interference signal with a signal bandwidth of 2MHz and continuously adjustable signal power. The dual-polarized four-ridged horn antenna is directly facing the multi-element adaptive nulling antenna equipped on the navigation device under test.

[0040] Adjust the interference signal transmission power to bring the navigation device under test to a critical state between positioning and non-positioning. Place a standard gain horn antenna at the location of the antenna under test and connect it to a spectrum analyzer. Measure the interference signal power value at this point, record the data, and use it as an evaluation benchmark. Figure 3 As shown.

[0041] During this process, the polarization agile circuit continuously switches the transmit polarization state according to the set frequency and duty cycle, forming a dynamically changing polarization interference field to simulate the polarization interference characteristics in a complex electromagnetic environment during actual combat.

[0042] Step 4: Evaluation of the interference effect of polarization agile signal: Keeping other test conditions unchanged, adjust the output frequency of the rectangular wave signal generator module in sequence, including: 1kHz, 10kHz, 50kHz, 100kHz, and repeat the test procedure in Step 3. Record the power value of the interference signal received at the adaptive nulling antenna position under different polarization switching rates.

[0043] By comparing received power data at different polarization switching rates, the impact of polarization switching rate on the anti-interference capability of navigation equipment is analyzed. Experimental results show that as the polarization switching frequency changes, interference signals with varying polarization cause the adaptive nulling antenna to misjudge the number and direction of interference signals and continuously consume its computational resources, thereby significantly reducing the suppression efficiency of the adaptive nulling system and improving its interference effectiveness.

[0044] In addition, the impact of polarization duration on interference performance can be studied by combining different duty cycle configurations, and the interference strategy can be further optimized.

[0045] Functional Expansion and Extension: To further expand the functional applications of this polarization agile signal generation circuit, a single-pole multi-throw RF switch, including the HMC253, can be selected. Its multiple output terminals can be connected to multiple dual-polarized horn antennas or slant-polarized antenna units with different polarization characteristics, thereby realizing rapid switching between various polarization forms, including horizontal polarization, vertical polarization, and ±45° slant polarization.

[0046] Meanwhile, the pitch and azimuth angles of the dual-polarized quad-ridged horn antenna can be manually or electrically adjusted via the matching antenna angle adjustment bracket module, achieving physical alignment and dynamic offset of the spatial polarization direction, thereby enhancing the spatial directivity and adaptability of interference signals.

[0047] Example 3: In this example, the polarization agile signal generation circuit includes the following modules: RF switch control module 101: adopts a single-pole double-throw RF switch chip of model 349LP4C; Rectangular wave signal generator module 102: It is based on an STM32F103 series microcontroller and integrates frequency adjustment buttons, duty cycle adjustment buttons and EEPROM storage unit. Dual-polarized quad-ridged horn antenna module 103: Model HD-1020DPHA6N, supports 1-2GHz frequency band, and has two independent feed ports for horizontal polarization and vertical polarization; Filtering and shaping circuit module: Composed of an RC low-pass filter circuit and a Schmitt trigger, used for edge shaping of rectangular wave signals; RF power detection module: Uses AD8362 RF power detector chip to monitor the RF signal strength of the output path in real time; Remote control interface module: Enables communication with PC via UART to USB module; Automatic calibration module: Implemented by the built-in software algorithm of the main control chip, it periodically verifies the accuracy of the control voltage and the response time of the RF switch; Status indicator module: Uses LED lights to display the current polarization channel, power supply status, and control signal status; Local display and interaction module: It uses a 0.96-inch OLED display and a rotary encoder to display the current setting parameters and supports manual adjustment.

[0048] The radio frequency signal source is connected to the input terminal IN of the radio frequency switch control module 101 via a connector; The two output terminals RF1 and RF2 of the RF switch module are connected to the horizontal polarization port and vertical polarization port of the dual-polarized quad-ridge horn antenna module 103 respectively via cables; The PWM output of the rectangular wave signal generator module 102 is connected to the RF switch control terminal "Vctl" after passing through the filter and shaping circuit module; The AD8362 power detection module is connected to the two output terminals of the RF switch, and its output analog voltage is connected to the ADC acquisition pin of the MCU. The UART interface module is connected to the serial port pin of the MCU to receive external control commands; The OLED display and rotary encoder are connected to the MCU's I²C interface to enable human-machine interaction. LED status indicators are connected to the MCU's general-purpose I / O port to display the current polarization state and system operating status.

[0049] System operation process: Initialization phase: After the system is powered on, the main control chip reads the previously set parameters stored in the EEPROM, including frequency and duty cycle; Initialize the OLED display and show the initial parameter values; Initialize the RF switch control terminal "Vctl" to a low level to ensure that the output is sent to the vertical polarization channel by default.

[0050] User operation phase: The user modifies the frequency and duty cycle via the rotary encoder or the FREQ / DUTY button; The modified parameters are displayed on the OLED screen in real time and written to the EEPROM for storage; The main control chip generates a corresponding square wave signal according to the set frequency, which is then output to the filtering and shaping module for processing and to drive the RF switch to switch.

[0051] Polarization switching phase: When the rectangular wave is high, the RF signal is output from the horizontal polarization port; when it is low, it is output from the vertical polarization port. The polarization switching rate is determined by the square wave frequency, and the duration is controlled by the duty cycle; The power detection module samples the strength of the two output signals in real time and displays the current power value on an OLED screen.

[0052] Remote control phase: Send UART commands via PC to remotely modify frequency and duty cycle parameters; After the command is parsed, the current running parameters are updated, and the parameter adjustment can be completed without manual intervention.

[0053] Automatic calibration phase: The system initiates a self-test program every fixed time interval, including 1 minute; The calibration includes control voltage accuracy, RF switch response delay, and power detection consistency. If the deviation exceeds the threshold, the parameters will be automatically adjusted or the user will be prompted to check the hardware connection.

[0054] Testing and Verification: The circuit of this embodiment was deployed in a navigation interference test environment. The interference signal source was a digital modulation signal generator with an output frequency of 1575.42MHz and continuously adjustable power. A dual-polarized four-ridged horn antenna was used to transmit the interference signal to the multi-element null-tuned antenna of the navigation device under test.

[0055] By adjusting the output frequency of the rectangular wave signal generator module, including 1kHz, 10kHz, and 100kHz, the changes in the anti-interference performance of the navigation device under different polarization switching rates were observed. Simultaneously, the effects of different duty cycles, including 30%, 50%, and 70%, on the interference effect were recorded.

[0056] This circuit can stably achieve a polarization switching frequency of up to 150kHz, a polarization isolation better than 20dB, and a standing wave ratio of less than 2.5, meeting the basic requirements of navigation jamming systems for polarization agility technology.

[0057] The above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described in the present invention. Although the present invention has been described in detail with reference to the above embodiments, the present invention is not limited to the specific embodiments described above. Therefore, any modifications or substitutions to the present invention, and all technical solutions and improvements that do not depart from the spirit and scope of the invention, are covered within the scope of the claims of the present invention.

Claims

1. A simple and practical polarization-agile signal generation circuit, characterized in that, The system includes a radio frequency switch control module (101), a rectangular wave signal generator module (102), a dual-polarized quadrangular horn antenna module (103), and a signal source switching control module (104). The input terminal of the radio frequency switch control module (101) is connected to an interference signal source. The radio frequency switch control module (101) includes a single-pole double-throw radio frequency switch, and its output terminal is connected to the two orthogonal polarization input ports of the dual-polarized quadrangular horn antenna module (103). The PWM output terminal of the rectangular wave signal generator module (102) is connected to the control terminal "Vctl" of the radio frequency switch control module (101) to control the switching of the radio frequency switch between the two outputs.

2. The polarization agile signal generation circuit according to claim 1, characterized in that, The radio frequency switch control module (101) uses a radio frequency switch device of model 349LP4C, with a working frequency range of 0.1GHz to 6.0GHz and a power supply voltage of 3.3 to 5V. When the control voltage is high (2 to 5V), the first output terminal "RF1" is turned on and the second output terminal "RF2" is turned off; when the control voltage is low (0 to 0.8V), the second output terminal "RF2" is turned on and the first output terminal "RF1" is turned off.

3. The polarization agile signal generation circuit according to claim 1, characterized in that, The rectangular wave signal generator module (102) includes a programmable controller unit, a key input unit, and an EEPROM storage unit. The programmable controller unit generates square wave signals through an internal timer. The key input unit includes four independent buttons: "FREQ+", "FREQ−", "DUTY+", and "DUTY−", which support short press (increase or decrease by one unit) and long press (quick increase or decrease) operation modes. The EEPROM storage unit is used to save the currently set frequency and duty cycle parameters, and the settings are not lost after power failure.

4. The polarization agile signal generation circuit according to claim 1, characterized in that, The square wave signal output by the rectangular wave signal generator module (102) has a frequency adjustable in the range of 1Hz to 150kHz, a duty cycle adjustable in 1% increments between 10% and 90%, an output amplitude equal to the power supply voltage, and an output current of 5 to 30mA.

5. The polarization agile signal generation circuit according to claim 1, characterized in that, The dual-polarized quad-ridge horn antenna module (103) covers a frequency range of 1 to 2 GHz and includes two independent feed channels: horizontal polarization and vertical polarization. Each channel is equipped with an N-type connector, and the polarization isolation is not less than 20 dB and the standing wave ratio is not greater than 2.

5.

6. The polarization agile signal generation circuit according to claim 1, characterized in that, It also includes an antenna angle adjustment bracket module for mounting the dual-polarized quad-ridge horn antenna module (103) and allowing it to rotate ±30° in the horizontal plane and pitch ±15° in the vertical plane.

7. The polarization agile signal generation circuit according to claim 1, characterized in that, The radio frequency switch control module (101) can be replaced with a single-pole multi-throw radio frequency switch structure, with its multiple output terminals connected to different polarization input ports of multiple dual-polarized horn antennas, enabling rapid switching between horizontal polarization, vertical polarization and slant polarization.

8. The polarization agile signal generation circuit according to claim 1, characterized in that, It also includes a remote control interface module, which is connected to the rectangular wave signal generator module (102) via UART or I²C communication protocol. This module is used to receive frequency and duty cycle configuration commands sent by external control devices and update the current operating parameters.

9. The polarization agile signal generation circuit according to claim 1, characterized in that, The rectangular wave signal generator module (102) has a built-in regulated power supply management unit with an input voltage range of 3.3V to 30V. The output PWM amplitude is equal to the power supply voltage, which is beneficial to achieve matching with the "Vctl" voltage of the control terminal of the radio frequency switch module (101).

10. The polarization agile signal generation circuit according to claim 1, characterized in that, It also includes a status indication module, an RF power detection module, a filtering and shaping module, a signal source switching module, an automatic calibration module, and a local display and interaction module. The status indication module consists of LED indicators, which are used to indicate the current conduction path of the RF switch, the working status of the rectangular wave signal generator, and the system power supply status, respectively. The RF power detection module is integrated into the output path of the RF switch control module (101) and is used to monitor the power intensity of each output RF signal in real time and feed the detection results back to the main control unit or an external display device. The filtering and shaping module is located between the output end of the rectangular wave signal generator module (102) and the RF switch control module (101) and is used to filter and shape the square wave signal to improve the stability and anti-interference capability of the control signal. The signal source switching module (104) is located between the interference signal source and the RF switch control module (101) and is used to select the access of different types of interference signal sources, including CW continuous wave signal source, LFM linear frequency modulation signal source or multi-tone interference signal source. The automatic calibration module is used to periodically perform self-checks and error compensation on the RF switch control logic, rectangular wave output accuracy, and antenna polarization matching status to ensure the long-term stability of the system. The local display and interaction module integrates an OLED display screen and a rotary encoder to display the current frequency, duty cycle, and polarization status information in real time.

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