Microwave circuit with adjustable power frequency and dot frequency source

Abstract

The utility model discloses a power frequency adjustable microwave circuit and a dot frequency source, relates to the field of electronic circuits, and solves the problem that the output frequency of a dot frequency source microwave circuit is not adjustable. According to actual requirements, the output frequency signal of the phase-locked loop is adjusted through the single-chip microcomputer, the capacitance value of the variable capacitance diode is changed by controlling the voltage of the variable capacitance diode, the range of the output signal is adjusted by changing the resonant frequency of the circuit, and the size of the output signal is adjusted through the digital attenuator, so that the requirements of different application scenes are met; through combination of the voltage-controlled oscillation module, the phase-locked loop, the adjustable filtering module and the single-chip microcomputer, accurate adjustment of microwave signal output frequency points and power is realized.

Description

Technical Field

[0001] This utility model relates to the field of electronic circuits, and in particular to a power-frequency adjustable microwave circuit and a point frequency source. Background Technology

[0002] Most existing point-frequency microwave circuits on the market output a fixed frequency and lack adjustable output frequency functionality. Typically, the signal generator uses an active crystal oscillator to output a fixed point-frequency signal. This signal is first amplified by a driver amplifier, and then sent to a final amplifier to output a high-power signal. Finally, the signal passes through a harmonic suppression filter circuit to filter out the second and third harmonics, ensuring that the final output is a high-power, clean point-frequency signal.

[0003] As a fixed signal source, crystal oscillators cannot achieve adjustable output frequency, which limits the diversity of their applications. If a frequency change is required, the entire microwave solid-state source may have to be replaced, which undoubtedly increases the maintenance and upgrade costs of the system.

[0004] Therefore, how to solve the problem of the inability to adjust the output frequency of a point frequency source microwave circuit is a technical problem that urgently needs to be solved by those in this field. Utility Model Content

[0005] The purpose of this invention is to provide a power-frequency adjustable microwave circuit and a point frequency source, thereby solving the problem that the output frequency of the point frequency source microwave circuit is not adjustable.

[0006] To solve the above-mentioned technical problems, this utility model provides a power-frequency adjustable microwave circuit, comprising:

[0007] Voltage-controlled oscillator module, phase-locked loop, adjustable filter module, power amplifier module, digital attenuator, power supply module, microcontroller;

[0008] The output terminal of the voltage-controlled oscillator module is connected to the input terminal of the phase-locked loop, the output terminal of the phase-locked loop is connected to the input terminal of the adjustable filter module, the output terminal of the adjustable filter module is connected to the input terminal of the power amplifier module, and the output terminal of the power amplifier module is connected to the input terminal of the digital attenuator.

[0009] The power supply module is connected to the voltage-controlled oscillator module, the phase-locked loop, the adjustable filter module, the power amplifier module, the digital attenuator, and the microcontroller, respectively; the microcontroller is connected to the phase-locked loop and the adjustable filter module.

[0010] As an optional solution, the above-mentioned power-frequency adjustable microwave circuit also includes: a temperature detection module;

[0011] The temperature detection module is located at the power amplifier module; the temperature detection module is connected to the power supply module and the microcontroller respectively.

[0012] As an optional solution, in the above-mentioned power-frequency adjustable microwave circuit, the voltage-controlled oscillator module includes: a first capacitor, a second capacitor, a third capacitor, a first inductor, a first resistor, a second resistor, a third resistor, and a voltage-controlled oscillator;

[0013] The output terminal of the power module is connected to the first terminal of the first capacitor and the first terminal of the first inductor. The second terminal of the first capacitor is grounded. The second terminal of the first inductor is connected to the input terminal of the voltage-controlled oscillator. The output terminal of the voltage-controlled oscillator is connected to the first terminal of the second capacitor. The second terminal of the second capacitor is connected to the first terminal of the first resistor and the first terminal of the second resistor. The second terminal of the second resistor is connected to the first terminal of the third resistor and the first terminal of the third capacitor. The second terminals of the first resistor and the third resistor are grounded. The second terminal of the third capacitor is connected to the phase-locked loop.

[0014] As an optional solution, in the above-mentioned power frequency adjustable microwave circuit, the adjustable filter module includes: a second inductor, a third inductor, a fourth inductor, a fifth inductor, a sixth inductor, a seventh inductor, an eighth inductor, a ninth inductor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, and six adjustable resistor modules.

[0015] The adjustable resistor module includes: a first adjustable resistor, a fourth resistor, a fifth resistor, and a first diode; the first end of the first adjustable resistor is connected to a power supply, the second end of the first adjustable resistor is connected to the first end of the fourth resistor and the first end of the fifth resistor, the second end of the fourth resistor is grounded, the second end of the fifth resistor is connected to the negative terminal of the first diode, and the positive terminal of the first diode is grounded.

[0016] The output terminal of the phase-locked loop is connected to the first terminal of the second inductor. The second inductor, the third inductor, the fourth inductor, the fifth inductor, the sixth inductor, and the seventh inductor are connected in series. The first terminal of the fourth capacitor is connected to the first terminal of the second inductor. The first terminal of the fifth capacitor is connected to the first terminal of the third inductor. The first terminal of the sixth capacitor is connected to the first terminal of the fourth inductor. The first terminal of the seventh capacitor is connected to the first terminal of the fifth inductor. The first terminal of the eighth inductor is connected to the first terminal of the sixth inductor, and the second terminal of the eighth inductor is connected to the first terminal of the eighth capacitor. The first terminal of the ninth inductor is connected to the first terminal of the seventh inductor, and the second terminal of the ninth inductor is connected to the first terminal of the ninth capacitor.

[0017] The second terminals of the fourth, fifth, sixth, seventh, eighth, and ninth capacitors are respectively connected to the negative terminals of the first diodes of each of the adjustable resistor modules;

[0018] The second terminal of the seventh inductor serves as the output terminal of the adjustable filter module.

[0019] As an optional solution, the above-mentioned power-frequency adjustable microwave circuit further includes: a third-order passive loop filter; the charge pump output terminal of the phase-locked loop is connected to the input terminal of the third-order passive loop filter;

[0020] The third-order passive loop filter includes: a sixth resistor, a seventh resistor, a tenth capacitor, an eleventh capacitor, and a twelfth capacitor;

[0021] The charge pump output terminal of the phase-locked loop is connected to the first terminal of the sixth resistor and the first terminal of the tenth capacitor. The second terminal of the tenth capacitor is grounded. The second terminal of the sixth resistor is connected to the first terminal of the eleventh capacitor and the first terminal of the twelfth capacitor. The second terminal of the eleventh capacitor is grounded through the seventh resistor. The twelfth capacitor is grounded.

[0022] As an optional solution, in the above-mentioned power frequency adjustable microwave circuit, the power amplification module includes: a control circuit and an amplification circuit;

[0023] The control circuit is connected to the microcontroller, the control circuit is connected to the amplifier circuit, the input terminal of the amplifier circuit is connected to the output terminal of the adjustable filter module, and the output terminal of the amplifier circuit is connected to the input terminal of the digital attenuator.

[0024] The amplification circuit includes: a first current transformer, a second current transformer, a third current transformer, an amplifier, a tenth inductor, an eleventh inductor, a thirteenth capacitor, a fourteenth capacitor, an eighth resistor, a ninth resistor, a second adjustable resistor, and a Zener diode.

[0025] The output terminal of the adjustable filter module is connected to the first terminal of the primary coil of the first current transformer. The second terminal of the primary coil of the first current transformer is connected to the input terminal of the amplifier, the first terminal of the secondary coil of the first current transformer, and the first terminal of the eighth resistor. The second terminal of the secondary coil of the first current transformer is grounded. The output terminal of the amplifier is connected to the first terminal of the tenth inductor, the first terminal of the primary coil of the second current transformer, the first terminal of the primary coil of the third current transformer, and the first terminal of the secondary coil of the third current transformer. The second terminal of the primary coil of the second current transformer is connected to the second terminal of the primary coil of the third current transformer and the first terminal of the secondary coil of the second current transformer. The second terminal of the secondary coil of the third current transformer serves as the output terminal of the amplifier circuit.

[0026] The second terminal of the tenth inductor is connected to the first terminal of the fourteenth capacitor and the first terminal of the ninth resistor. The second terminal of the fourteenth capacitor is grounded. The second terminal of the ninth resistor is connected to the first terminal of the second adjustable resistor, the negative terminal of the Zener diode, and the power supply terminal. The second terminal of the second adjustable resistor and the positive terminal of the Zener diode are grounded.

[0027] The second end of the eighth resistor is connected to the first end of the thirteenth capacitor and the control circuit through the eleventh inductor, and the second end of the thirteenth capacitor is grounded.

[0028] As an optional solution, in the above-mentioned power-frequency adjustable microwave circuit, the control circuit includes: a first transistor, a second transistor, a tenth resistor, and an eleventh resistor;

[0029] The first terminal of the thirteenth capacitor is connected to the first terminal of the second transistor, the second terminal of the second transistor is connected to the first terminal of the twelfth resistor, the control terminal of the second transistor is connected to the second terminal of the twelfth resistor and the first terminal of the eleventh resistor, the second terminal of the eleventh resistor is connected to the first terminal of the first transistor, the second terminal of the first transistor is grounded, and the control terminal of the first transistor is connected to the microcontroller.

[0030] As an alternative, in the above-mentioned power frequency adjustable microwave circuit, the power supply module includes a first step-down circuit, a second step-down circuit, and two dual-channel step-down circuits;

[0031] The power supply is connected to the input terminal of the first step-down circuit, the output terminal of the first step-down circuit is connected to the input terminal of the second step-down circuit, the output terminal of the second step-down circuit is connected to the input terminals of the two dual-channel step-down circuits respectively, and the four output terminals of the two dual-channel step-down circuits serve as power output terminals.

[0032] As an alternative, in the aforementioned power-frequency adjustable microwave circuit, the microcontroller is connected to the phase-locked loop via a level conversion circuit.

[0033] To address the aforementioned problems, this invention also provides a point frequency source, including the aforementioned power-frequency adjustable microwave circuit.

[0034] This utility model provides a power-frequency adjustable microwave circuit, comprising: a voltage-controlled oscillator (VCO) module, a phase-locked loop (PLL), an adjustable filter module, a power amplifier module, a digital attenuator, a power supply module, and a microcontroller. The output of the VCO module is connected to the input of the PLL, the output of the PLL is connected to the input of the adjustable filter module, the output of the adjustable filter module is connected to the input of the power amplifier module, and the output of the power amplifier module is connected to the input of the digital attenuator. The power supply module is connected to the VCO module, PLL, adjustable filter module, power amplifier module, digital attenuator, and microcontroller. The microcontroller is connected to the PLL and the adjustable filter module. Users can adjust the output frequency signal of the PLL using the microcontroller and change the capacitance of the varactor diode by controlling its voltage, thereby changing the resonant frequency of the circuit and adjusting the output signal range. The magnitude of the output signal can also be adjusted using the digital attenuator, thus meeting the needs of different application scenarios. By combining the VCO module, PLL, adjustable filter module, and microcontroller, precise adjustment of the microwave signal output frequency and power is achieved.

[0035] In addition, this utility model also provides a point frequency source, including the above-mentioned power and frequency adjustable microwave circuit, with the same effect. Attached Figure Description

[0036] To more clearly illustrate the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 A schematic diagram of a power-frequency adjustable microwave circuit provided by this utility model;

[0038] Figure 2 A circuit diagram of a voltage-controlled oscillation module provided by this utility model;

[0039] Figure 3 A circuit diagram of an adjustable filter module provided by this utility model;

[0040] Figure 4 A circuit diagram of a third-order passive loop filter provided by this utility model;

[0041] Figure 5 A schematic diagram of a phase-locked loop provided by this utility model;

[0042] Figure 6 A circuit diagram of a power amplifier module provided by this utility model;

[0043] Figure 7A circuit diagram of a power supply module provided by this utility model;

[0044] Figure 8 A circuit diagram of a level conversion circuit provided by this utility model.

[0045] The reference numerals in the attached figures are as follows:

[0046] 11-Voltage-controlled oscillator module, 12-Phase-locked loop, 13-Adjustable filter module, 14-Power amplifier module, 15-Digital attenuator, 16-Power supply module, 17-Microcontroller, 18-Temperature detection module, 131-Adjustable resistor module, 161-First step-down circuit, 162-Second step-down circuit, 163-Dual-channel step-down circuit. Detailed Implementation

[0047] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0048] The core of this utility model is to provide a microwave circuit with adjustable power and frequency and a point frequency source.

[0049] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0050] To address the aforementioned problems, this invention provides a power-frequency adjustable microwave circuit. Figure 1 A schematic diagram of a power-frequency adjustable microwave circuit is provided for this utility model, as shown below. Figure 1 As shown, it includes:

[0051] 11. Voltage-controlled oscillator module; 12. Phase-locked loop; 13. Adjustable filter module; 14. Power amplifier module; 15. Digital attenuator; 16. Power supply module; 17. Microcontroller.

[0052] The output of the voltage-controlled oscillator module 11 is connected to the input of the phase-locked loop 12, the output of the phase-locked loop 12 is connected to the input of the adjustable filter module 13, the output of the adjustable filter module 13 is connected to the input of the power amplifier module 14, and the output of the power amplifier module 14 is connected to the input of the digital attenuator 15.

[0053] The power supply module 16 is connected to the voltage-controlled oscillator module 11, phase-locked loop 12, adjustable filter module 13, power amplifier module 14, digital attenuator 15, and microcontroller 17 respectively; the microcontroller 17 is connected to the phase-locked loop 12 and the adjustable filter module 13.

[0054] The voltage-controlled oscillator module 11 (VCO) is responsible for generating the initial microwave signal. By adjusting the voltage, the oscillation frequency can be changed, thereby adjusting the frequency. The power supply module 16 outputs a specified voltage signal to the voltage-controlled oscillator module 11 to adjust the magnitude of the microwave signal.

[0055] The main function of the phase-locked loop (PLL) 12 is to achieve automatic phase locking and eliminate frequency errors. It receives the signal generated by the VCO and locks it to a stable frequency. The PLL 12 is controlled by the microcontroller 17 to ensure the stability of the frequency and phase of the output signal and improve signal quality.

[0056] The adjustable filter module 13 filters the signal output from the phase-locked loop 12 to eliminate unwanted frequency components and retain only the desired signal. The filter parameters are controlled and adjusted by the microcontroller 17 to adapt to different signal processing requirements.

[0057] The power amplifier module 14 amplifies the filtered signal to the required power level to meet transmission or application needs. The output of this module is connected to the input of the digital attenuator 15 for final signal power adjustment.

[0058] The main function of the digital attenuator 15 is to precisely adjust the amplitude of the signal through digital control signals, and further adjust the power of the signal output after amplification by the power amplifier module 14, so as to precisely control the strength of the output signal.

[0059] The power module 16 provides a stable power supply for the entire circuit system, ensuring that each module can work normally. Specifically, it provides different power supply voltages and designs the power output circuit according to the actual voltage requirements.

[0060] The microcontroller 17 is connected to the phase-locked loop 12 and the adjustable filter module 13. It adjusts the frequency and filtering characteristics by sending control signals to achieve precise control of the entire circuit.

[0061] The power-frequency adjustable microwave circuit provided in this application includes: a voltage-controlled oscillator module 11, a phase-locked loop 12, an adjustable filter module 13, a power amplifier module 14, a digital attenuator 15, a power supply module 16, and a microcontroller 17. The output terminal of the voltage-controlled oscillator module 11 is connected to the input terminal of the phase-locked loop 12, the output terminal of the phase-locked loop 12 is connected to the input terminal of the adjustable filter module 13, the output terminal of the adjustable filter module 13 is connected to the input terminal of the power amplifier module 14, and the output terminal of the power amplifier module 14 is connected to the input terminal of the digital attenuator 15. The power supply module 16 is connected to the voltage-controlled oscillator module 11, the phase-locked loop 12, the adjustable filter module 13, the power amplifier module 14, the digital attenuator 15, and the microcontroller 17. The microcontroller 17 is connected to the phase-locked loop 12 and the adjustable filter module 13. According to actual needs, users can adjust the output frequency signal of the phase-locked loop 12 by using the microcontroller 17 and change the capacitance value by controlling the voltage of the varactor diode to change the resonant frequency of the circuit to adjust the output signal range. The magnitude of the output signal can be adjusted by using the digital attenuator 15, thereby meeting the needs of different application scenarios. By combining the voltage-controlled oscillator module 11, the phase-locked loop 12, the adjustable filter module 13, and the microcontroller 17, the precise adjustment of the microwave signal output frequency and power is realized.

[0062] Furthermore, such as Figure 1 As shown, it also includes: a temperature detection module 18;

[0063] The temperature detection module 18 is located at the power amplifier module 14; the temperature detection module 18 is connected to the power supply module 16 and the microcontroller 17 respectively.

[0064] A temperature detection module 18 is located at the chip of the power amplifier module 14 to monitor the temperature of the power amplifier module 14 in real time. Since the power amplifier module 14 may generate a lot of heat during operation, temperature detection is crucial for preventing overheating and protecting the circuit.

[0065] The connection between the temperature detection module 18 and the power module 16 provides the necessary power to ensure that the temperature detection module 18 can work normally.

[0066] The temperature detection module 18 is connected to the microcontroller 17 to transmit the detected temperature data to the microcontroller 17. The microcontroller 17 can use this data to determine whether the power amplifier module 14 is operating normally and take corresponding control measures, such as reducing power output or shutting down the power amplifier module 14, to prevent overheating damage.

[0067] By incorporating a temperature detection module 18 at the power amplifier module 14, the module's temperature can be monitored in real time, allowing for timely detection of overheating issues and improving circuit safety and reliability. The microcontroller 17 can take proactive measures based on the data provided by the temperature detection module 18, such as adjusting the operating state of the power amplifier module 14, to prevent equipment damage due to overheating. The addition of the temperature detection module 18 enables the circuit to operate stably even in high-temperature environments, extending the equipment's lifespan.

[0068] The newly added temperature detection module 18 provides important safety assurance for the adjustable point frequency source microwave circuit. It not only improves the safety and reliability of the circuit, but also enhances the automation and intelligence level of the circuit through intelligent temperature monitoring and control.

[0069] According to the above embodiments, in one specific embodiment... Figure 2 A circuit diagram of a voltage-controlled oscillator module 11 provided by this utility model is shown below. Figure 2 As shown, the voltage-controlled oscillator module 11 includes: a first capacitor C1, a second capacitor C2, a third capacitor C3, a first inductor L1, a first resistor R1, a second resistor R2, a third resistor R3, and a voltage-controlled oscillator U1;

[0070] The output terminal of the power module 16 is connected to the first terminal of the first capacitor C1 and the first terminal of the first inductor L1. The second terminal of the first capacitor C1 is grounded. The second terminal of the first inductor L1 is connected to the input terminal of the voltage-controlled oscillator U1. The output terminal of the voltage-controlled oscillator U1 is connected to the first terminal of the second capacitor C2. The second terminal of the second capacitor C2 is connected to the first terminal of the first resistor R1 and the first terminal of the second resistor R2. The second terminal of the second resistor R2 is connected to the first terminal of the third resistor R3 and the first terminal of the third capacitor C3. The second terminals of the first resistor R1 and the third resistor R3 are grounded. The second terminal of the third capacitor C3 is connected to the phase-locked loop 12 (Ref_in).

[0071] The first capacitor C1 is connected to the output terminal of the power module 16 and one end of the first inductor L1, serving as a filter and energy storage unit. The other end of the first capacitor C1 is connected to the input terminal of the voltage-controlled oscillator U1, forming an oscillation circuit together with the capacitor.

[0072] The voltage-controlled oscillator U1 (VCO) receives a signal from the first inductor L1 and adjusts the oscillation frequency according to the control voltage. Its output is connected to one end of the second capacitor C2.

[0073] The first resistor R1, the second resistor R2, and the third resistor R3 constitute a PI attenuation circuit, which reduces the power of the input signal to achieve attenuation.

[0074] By adjusting the control voltage of the voltage-controlled oscillator U1, the oscillation frequency can be precisely controlled to meet the needs of different application scenarios.

[0075] According to the above embodiments, in one specific embodiment... Figure 3 A circuit diagram of an adjustable filter module 13 provided by this utility model is shown below. Figure 3 As shown, the adjustable filter module 13 includes: a second inductor L2, a third inductor L3, a fourth inductor L4, a fifth inductor L5, a sixth inductor L6, a seventh inductor L7, an eighth inductor L8, a ninth inductor L9, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7, an eighth capacitor C8, a ninth capacitor C9, and six adjustable resistor modules;

[0076] The adjustable resistor module includes: a first adjustable resistor RL1, a fourth resistor R4, a fifth resistor R5, and a first diode D1; the first end of the first adjustable resistor RL1 is connected to the power supply, the second end of the first adjustable resistor RL1 is connected to the first end of the fourth resistor R4 and the first end of the fifth resistor R5, the second end of the fourth resistor R4 is grounded, the second end of the fifth resistor R5 is connected to the negative terminal of the first diode D1, and the positive terminal of the first diode D1 is grounded.

[0077] The output terminal of the phase-locked loop 12 is connected to the first terminal of the second inductor L2. The second inductor L2, the third inductor L3, the fourth inductor L4, the fifth inductor L5, the sixth inductor L6, and the seventh inductor L7 are connected in series. The first terminal of the fourth capacitor C4 is connected to the first terminal of the second inductor L2. The first terminal of the fifth capacitor C5 is connected to the first terminal of the third inductor L3. The first terminal of the sixth capacitor C6 is connected to the first terminal of the fourth inductor L4. The first terminal of the seventh capacitor C7 is connected to the first terminal of the fifth inductor L5. The first terminal of the eighth inductor L8 is connected to the first terminal of the sixth inductor L6, and the second terminal of the eighth inductor L8 is connected to the first terminal of the eighth capacitor C8. The first terminal of the ninth inductor L9 is connected to the first terminal of the seventh inductor L7, and the second terminal of the ninth inductor L9 is connected to the first terminal of the ninth capacitor C9.

[0078] The second terminals of the fourth capacitor C4, the fifth capacitor C5, the sixth capacitor C6, the seventh capacitor C7, the eighth capacitor C8, and the ninth capacitor C9 are respectively connected to the negative terminal of the first diode D1 of each adjustable resistor module.

[0079] The second terminal of the seventh inductor L7 serves as the output terminal of the adjustable filter module 13.

[0080] In one implementation, the output signal port impedance of the phase-locked loop 12 is 100Ω. A 7th-order Chebyshev low-pass filter not only achieves impedance matching from 100Ω to 50Ω but also filters the input signal. This is followed by a 5th-order inverse Chebyshev low-pass filter. Inter-stage matching is simulated using ADS (a microwave circuit and communication system simulation tool). When the input signal enters the first low-pass filter, high-frequency components are filtered out, retaining only low-frequency components. The filtered signal then passes through a second low-pass filter, removing the remaining high-frequency components to obtain a cleaner low-frequency signal. This design combination achieves no change in signal phase, strong noise immunity, strong high-frequency suppression, low in-band insertion loss, and low ripple. Subsequently, the resonant frequency can be changed by controlling the adjustable resistors to divide the +5V voltage and apply it to the first diode D1 (varactor diode) of each adjustable resistor module, thus achieving frequency adjustment. Varactor diodes have the advantages of fast tuning speed and high reliability.

[0081] Each adjustable resistor module includes a first adjustable resistor RL1, a fourth resistor R4, a fifth resistor R5, and a first diode. The first adjustable resistor RL1 has an adjustable value and is used to adjust the resonant frequency and bandwidth of the filter. The fourth resistor R4 and the fifth resistor R5 are connected in series with the adjustable resistor to provide a stable bias and reference point. The first diode D1 is connected to the second terminal of the fifth resistor R5 for rectifier protection circuitry.

[0082] According to the above embodiments, in one specific embodiment... Figure 4 A circuit diagram of a third-order passive loop filter provided by this utility model is shown below. Figure 4 As shown, it also includes: a third-order passive loop filter; the charge pump output of the phase-locked loop 12 is connected to the input of the third-order passive loop filter;

[0083] The third-order passive loop filter includes: the sixth resistor R6, the seventh resistor R7, the tenth capacitor C10, the eleventh capacitor C11, and the twelfth capacitor C12.

[0084] The charge pump output terminal TUNE of phase-locked loop 12 is connected to the first terminal of the sixth resistor R6 and the first terminal of the tenth capacitor C10. The second terminal of the tenth capacitor C10 is grounded. The second terminal of the sixth resistor R6 is connected to the first terminal of the eleventh capacitor C11 and the first terminal of the twelfth capacitor C12. The second terminal of the eleventh capacitor C11 is grounded through the seventh resistor R7, and the twelfth capacitor C12 is grounded.

[0085] Figure 5 A schematic diagram of a phase-locked loop 12 provided by this utility model is shown below. Figure 5 As shown, the charge pump output of phase-locked loop U2 is connected to a third-order passive loop filter.

[0086] Loop bandwidth and phase margin are important indicators for evaluating the performance of a phase-locked loop (PLL). A wider loop bandwidth results in a shorter locking time, but correspondingly, phase noise deteriorates. While active loop filters offer advantages in some aspects, they increase phase noise, system complexity, and cost. Therefore, this design employs a third-order passive loop filter (3R3C structure) to minimize phase noise while maintaining locking speed, and to preserve design simplicity and cost-effectiveness.

[0087] According to the above embodiments, in one specific embodiment... Figure 6 A circuit diagram of a power amplifier module 14 provided by this utility model is shown below. Figure 6 As shown, the power amplifier module 14 includes: a control circuit and an amplifier circuit;

[0088] The control circuit is connected to the microcontroller 17, the control circuit is connected to the amplifier circuit, the input terminal of the amplifier circuit is connected to the output terminal of the adjustable filter module 13, and the output terminal of the amplifier circuit is connected to the input terminal of the digital attenuator 15.

[0089] The amplifier circuit includes: a first current transformer T1, a second current transformer T2, a third current transformer T3, an amplifier U3, a tenth inductor L10, an eleventh inductor L11, a thirteenth capacitor C13, a fourteenth capacitor C14, an eighth resistor R8, a ninth resistor R9, a second adjustable resistor RL2, and a Zener diode D2.

[0090] The output terminal of the adjustable filter module 13 is connected to the first terminal of the primary coil of the first current transformer T1. The second terminal of the primary coil of the first current transformer T1 is connected to the input terminal of the amplifier U3, the first terminal of the secondary coil of the first current transformer T1, and the first terminal of the eighth resistor R8. The second terminal of the secondary coil of the first current transformer T1 is grounded. The output terminal of the amplifier U3 is connected to the first terminal of the tenth inductor L10, the first terminal of the primary coil of the second current transformer T2, the first terminal of the primary coil of the third current transformer T3, and the first terminal of the secondary coil of the third current transformer T3. The second terminal of the primary coil of the second current transformer T2 is connected to the second terminal of the primary coil of the third current transformer T3 and the first terminal of the secondary coil of the second current transformer T2. The second terminal of the secondary coil of the third current transformer T3 serves as the output terminal of the amplifier circuit.

[0091] The second terminal of the tenth inductor L10 is connected to the first terminal of the fourteenth capacitor C14 and the first terminal of the ninth resistor R9. The second terminal of the fourteenth capacitor C14 is grounded. The second terminal of the ninth resistor R9 is connected to the first terminal of the second adjustable resistor RL2, the negative terminal of the Zener diode D2, and the power supply terminal. The second terminal of the second adjustable resistor RL2 and the positive terminal of the Zener diode D2 are grounded.

[0092] The second terminal of the eighth resistor R8 is connected to the first terminal of the thirteenth capacitor C13 and the control circuit through the eleventh inductor L11. The second terminal of the thirteenth capacitor C13 is grounded.

[0093] The control circuit is connected to the microcontroller 17, receives control signals, and is connected to the amplifier circuit to adjust the working state of the amplifier circuit according to the control signals.

[0094] An amplifier circuit includes multiple transformers, inductors, capacitors, resistors, and diodes for signal amplification and filtering. The use of transformers provides good signal isolation, reducing interference during signal transmission.

[0095] In one implementation, amplifier U3 is an NXP LDMOS amplifier U3, operating at a frequency of 1.8MHz-2GHz, capable of outputting 25W in the 30-512MHz range, with an actual gain of 17.1dB. This circuit uses the same chip to drive both the power amplifier and the final stage power amplifier, producing a 25W power output after two stages of amplification. The quiescent operating point of the power amplifier chip can be set by adjusting the second adjustable resistor RL2.

[0096] Specifically, the control circuit includes: a first transistor Q1, a second transistor Q2, a tenth resistor R10, and an eleventh resistor R11;

[0097] The first terminal of the thirteenth capacitor C13 is connected to the first terminal of the second transistor Q2. The second terminal of the second transistor Q2 is connected to the first terminal of the twelfth resistor R12. The control terminal of the second transistor Q2 is connected to the second terminal of the twelfth resistor R12 and the first terminal of the eleventh resistor R11. The second terminal of the eleventh resistor R11 is connected to the first terminal of the first transistor Q1. The second terminal of the first transistor Q1 is grounded. The control terminal of the first transistor Q1 is connected to the microcontroller 17.

[0098] The control terminal of the first transistor Q1 is connected to the I / O port SW-VG1 of the microcontroller 17 to control the input level at that point. The circuit uses the first transistor Q1, specifically an NMOS (N-Metal-Oxide-Semiconductor), and the second transistor Q2, specifically a PMOS (positive-channel Metal-Oxide-Semiconductor). When SW-VG1 receives a high-level input, the first transistor Q1 turns on, and its first terminal is grounded (GND). The VDD voltage is directly applied to the second terminal of the second transistor Q2. After being divided by the tenth resistor R10 and the eleventh resistor R11, the second transistor Q2 also turns on, and the VDD voltage is applied to the VG gate of the power amplifier U3, thereby controlling the operating state of the amplifier U3.

[0099] If the temperature detection circuit detects that the temperature is too high, it will communicate with the microcontroller 17 via the I / O port. After receiving the instruction, the microcontroller 17 will lower the level of SW-VG1, causing VG to have no output, and the power amplifier will stop working, thus realizing the function of the protection circuit.

[0100] According to the above embodiments, in one specific embodiment, the power module 16 includes a first step-down circuit 161, a second step-down circuit 162, and two dual-channel step-down circuits 163.

[0101] The power supply is connected to the input terminal of the first step-down circuit 161, the output terminal of the first step-down circuit 161 is connected to the input terminal of the second step-down circuit 162, the output terminal of the second step-down circuit 162 is connected to the input terminals of the two dual-channel step-down circuits 163 respectively, and the four output terminals of the two dual-channel step-down circuits 163 serve as power output terminals.

[0102] Figure 7 A circuit diagram of a power module 16 provided for this utility model is shown below. Figure 7 As shown, the +50V input voltage is converted to +24V by the first buck circuit 161. Then, the +24V voltage is converted again by the second buck circuit 162 to obtain a +5V output. This +5V voltage is supplied to two dual-channel buck circuits 163 (low-dropout linear regulators), enabling the U7 module to generate two +3.3V power outputs. The U8 module's VOUT1 generates +3.3V, and VOUT2 generates +1.8V, with different buck conversion conditions set according to the actual power supply requirements.

[0103] Specifically, both low-dropout linear regulators utilize the same model, the ADP223ACPZ-R7 linear regulator. The ADP223ACPZ-R7 is renowned for its low-noise characteristics, ensuring power output stability and effectively reducing potential interference to electronic equipment. Simultaneously, its high power supply rejection ratio (PSRR) allows the output voltage to remain stable even when the input voltage fluctuates, significantly improving the power supply's immunity to interference. This characteristic is particularly important for the phase-locked loop (PLL), as it ensures greater stability of the PLL's output signal in both frequency and phase, thereby enhancing the overall circuit performance and reliability.

[0104] Specifically, the microcontroller 17 is connected to the phase-locked loop 12 through a level conversion circuit.

[0105] The microcontroller 17 operates at a high level of 3.3V logic, while the phase-locked loop 12 chip may only be compatible with a 1.8V control logic level. Directly connecting the I / O port of the microcontroller 17 to the pin of the phase-locked loop 12 chip may cause a level mismatch, which may lead to communication failure or chip damage. In order to solve the level incompatibility problem, a level conversion circuit is added. Figure 8 A circuit diagram of a level conversion circuit provided by this utility model is shown below. Figure 8 As shown, the microcontroller's 17IO generates 0-3.3V high and low levels, which are converted to 0-1.8V via U9 and output to the various pins of the phase-locked loop (PLL) 12 chip for communication. Integer / fractional frequency division is implemented through the configuration register to ensure a stable differential signal output from the PLL 12. After passing through a balun, the differential signal achieves impedance conversion between the input and output ports, effectively reducing signal reflection and interference, thereby improving the quality and stability of signal transmission.

[0106] Finally, this application also provides a point frequency source, including the aforementioned power-frequency adjustable microwave circuit. The output frequency signal of the phase-locked loop 12 is adjusted by the microcontroller 17, and the capacitance value of the varactor diode is changed by controlling the voltage of the varactor diode, thereby changing the resonant frequency of the circuit to adjust the output signal range. The magnitude of the output signal is adjusted by the digital attenuator 15, thus meeting the needs of different application scenarios. By combining the voltage-controlled oscillator module 11, the phase-locked loop 12, the adjustable filter module 13, and the microcontroller 17, precise adjustment of the microwave signal output frequency and power is achieved.

[0107] The power-frequency adjustable microwave circuit and point frequency source provided by this utility model have been described in detail above. The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section. It should be noted that those skilled in the art can make several improvements and modifications to this utility model without departing from the principle of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model.

[0108] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

Claims

1. A power frequency adjustable microwave circuit, characterized by Include: Voltage controlled oscillation module (11), phase-locked loop (12), adjustable filter module (13), power amplifier module (14), digital attenuator (15), power module (16), single-chip microcomputer (17); The output end of the voltage controlled oscillation module (11) is connected with the input end of the phase-locked loop (12), the output end of the phase-locked loop (12) is connected with the input end of the adjustable filter module (13), the output end of the adjustable filter module (13) is connected with the input end of the power amplifier module (14), and the output end of the power amplifier module (14) is connected with the input end of the digital attenuator (15); The power module (16) is connected with the voltage controlled oscillation module (11), the phase-locked loop (12), the adjustable filter module (13), the power amplifier module (14), the digital attenuator (15) and the single-chip microcomputer (17) respectively, and the single-chip microcomputer (17) is connected with the phase-locked loop (12) and the adjustable filter module (13).

2. The power frequency tunable microwave circuit of claim 1, wherein, Also include: Temperature detection module (18); The temperature detection module (18) is arranged at the power amplifier module (14), and the temperature detection module (18) is connected with the power module (16) and the single-chip microcomputer (17) respectively.

3. The power frequency tunable microwave circuit of claim 1, wherein, The voltage controlled oscillation module (11) comprises a first capacitor, a second capacitor, a third capacitor, a first inductor, a first resistor, a second resistor, a third resistor and a voltage controlled oscillator. The output end of the power module (16) is connected with the first end of the first capacitor and the first end of the first inductor, the second end of the first capacitor is grounded, the second end of the first inductor is connected with the input end of the voltage controlled oscillator, the output end of the voltage controlled oscillator is connected with the first end of the second capacitor, the second end of the second capacitor is connected with the first end of the first resistor and the first end of the second resistor, the second end of the second resistor is connected with the first end of the third resistor and the first end of the third capacitor, the second ends of the first resistor and the third resistor are grounded, and the second end of the third capacitor is connected with the phase-locked loop (12).

4. The power frequency tunable microwave circuit of claim 3, wherein, The adjustable filter module (13) comprises a second inductor, a third inductor, a fourth inductor, a fifth inductor, a sixth inductor, a seventh inductor, an eighth inductor, a ninth inductor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor and six adjustable resistor modules (131). The adjustable resistor module (131) comprises a first adjustable resistor, a fourth resistor, a fifth resistor and a first diode, the first end of the first adjustable resistor is connected with a power supply, the second end of the first adjustable resistor is connected with the first end of the fourth resistor and the first end of the fifth resistor, the second end of the fourth resistor is grounded, the second end of the fifth resistor is connected with the negative electrode of the first diode, and the positive electrode of the first diode is grounded. The output end of the phase-locked loop (12) is connected with the first end of the second inductor, the second inductor, the third inductor, the fourth inductor, the fifth inductor, the sixth inductor and the seventh inductor are connected in series; the first end of the fourth capacitor is connected with the first end of the second inductor; the first end of the fifth capacitor is connected with the first end of the third inductor; the first end of the sixth capacitor is connected with the first end of the fourth inductor; the first end of the seventh capacitor is connected with the first end of the fifth inductor; the first end of the eighth inductor is connected with the first end of the sixth inductor, and the second end of the eighth inductor is connected with the first end of the eighth capacitor; the first end of the ninth inductor is connected with the first end of the seventh inductor, and the second end of the ninth inductor is connected with the first end of the ninth capacitor; The second ends of the fourth capacitor, the fifth capacitor, the sixth capacitor, the seventh capacitor, the eighth capacitor and the ninth capacitor are respectively connected with the negative poles of the first diodes of the adjustable resistance modules (131); The second end of the seventh inductor is used as the output end of the adjustable filter module (13).

5. The power frequency tunable microwave circuit of claim 1, wherein, Further comprising: A third-order passive loop filter; The charge pump output end of the phase-locked loop (12) is connected with the input end of the third-order passive loop filter; The third-order passive loop filter comprises a sixth resistor, a seventh resistor, a tenth capacitor, an eleventh capacitor and a twelfth capacitor; The charge pump output end of the phase-locked loop (12) is connected with the first end of the sixth resistor and the first end of the tenth capacitor, the second end of the tenth capacitor is grounded, the second end of the sixth resistor is connected with the first end of the eleventh capacitor and the first end of the twelfth capacitor, the second end of the eleventh capacitor is grounded through the seventh resistor, and the twelfth capacitor is grounded.

6. The power frequency tunable microwave circuit of claim 4, wherein, The power amplification module (14) comprises a control circuit and an amplification circuit; The control circuit is connected with the single-chip microcomputer (17), the control circuit is connected with the amplification circuit, the input end of the amplification circuit is connected with the output end of the adjustable filter module (13), and the output end of the amplification circuit is connected with the input end of the digital attenuator (15); The amplification circuit comprises a first mutual inductor, a second mutual inductor, a third mutual inductor, an amplifier, a tenth inductor, an eleventh inductor, a thirteenth capacitor, a fourteenth capacitor, an eighth resistor, a ninth resistor, a second adjustable resistor and a voltage stabilizing diode. The output end of the adjustable filter module (13) is connected with the first end of the primary coil of the first transformer, the second end of the primary coil of the first transformer is connected with the input end of the amplifier, the first end of the secondary coil of the first transformer, the first end of the eighth resistor, and the second end of the secondary coil of the first transformer is grounded; the output end of the amplifier is connected with the first end of the tenth inductor, the first end of the primary coil of the second transformer, the first end of the primary coil of the third transformer, and the first end of the secondary coil of the third transformer; the second end of the primary coil of the second transformer is connected with the second end of the primary coil of the third transformer and the first end of the secondary coil of the second transformer, and the second end of the secondary coil of the third transformer is used as the output end of the amplification circuit; The second end of the tenth inductor is connected with the first end of the fourteenth capacitor and the first end of the ninth resistor, the second end of the fourteenth capacitor is grounded, the second end of the ninth resistor is connected with the first end of the second adjustable resistor, the negative electrode of the voltage stabilizing diode, and the power supply end, and the second end of the second adjustable resistor and the positive electrode of the voltage stabilizing diode are grounded. The second end of the eighth resistor is connected with the first end of the thirteenth capacitor and the control circuit through the eleventh inductor, and the second end of the thirteenth capacitor is grounded.

7. The power frequency tunable microwave circuit of claim 6, wherein, The control circuit comprises a first transistor, a second transistor, a tenth resistor, an eleventh resistor, and a twelfth resistor. The first end of the thirteenth capacitor is connected with the first end of the second transistor, the second end of the second transistor is connected with the first end of the twelfth resistor, the control end of the second transistor is connected with the second end of the twelfth resistor and the first end of the eleventh resistor, the second end of the eleventh resistor is connected with the first end of the first transistor, the second end of the first transistor is grounded, and the control end of the first transistor is connected with a single-chip microcomputer (17).

8. The power frequency tunable microwave circuit of claim 1, wherein, The power supply module (16) comprises a first voltage reduction circuit (161), a second voltage reduction circuit (162), and two double-channel voltage reduction circuits (163). A power supply is connected with the input end of the first voltage reduction circuit (161), the output end of the first voltage reduction circuit (161) is connected with the input end of the second voltage reduction circuit (162), the output end of the second voltage reduction circuit (162) is respectively connected with the input end of two double-channel voltage reduction circuits (163), and four output ends of the two double-channel voltage reduction circuits (163) are used as power output ends.

9. The power frequency tunable microwave circuit of claim 5, wherein, The single-chip microcomputer (17) is connected with the phase-locked loop (12) through a level conversion circuit.

10. A point frequency source, characterized by The power frequency adjustable microwave circuit comprises the power frequency adjustable microwave circuit according to any one of claims 1-9. The power frequency adjustable microwave circuit comprises the power frequency adjustable microwave circuit according to any one of claims 1-9.

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