Microwave solid-state source generating circuit

Abstract

The invention discloses a microwave solid-state source generation circuit. Relates to the field of electronic circuits and solves the problem of high control cost of a microwave solid-state source. Stable microwave signals are generated through the crystal oscillator frequency selection circuit, signal level is adjusted through the adjustable attenuation circuit, frequency selection and preliminary attenuation adjustment of the signals are achieved through connection of the crystal oscillator frequency selection circuit and the adjustable attenuation circuit, the signals are amplified through the power amplification and control circuit, and the signals are output through the coupling circuit. The coupling output of signals is realized, the accurate control of the whole circuit and the stable control of the output power are realized through the single-chip microcomputer control circuit, and the system design is simplified while the microwave radiation effect can be realized.

Description

Technical Field

[0001] The present application relates to the field of electronic circuits, and in particular to a microwave solid-state source generating circuit. Background Art

[0002] Phase-Locked Loop (PLL) is an automatic control circuit that uses feedback control principles to achieve phase synchronization. It is mainly composed of a phase detector (PD), a loop filter (LF) and a voltage controlled oscillator (VCO). The working principle of the phase-locked loop is to compare the phase of the input signal with the phase of the output signal of the voltage controlled oscillator, filter and amplify it through the loop filter, output the control voltage, and adjust the phase and frequency of the output signal of the voltage controlled oscillator to keep it synchronized with the phase and frequency of the input signal.

[0003] The controller controls the phase detector frequency and voltage-controlled oscillator of the phase-locked loop to achieve the adjustment of the fixed frequency and power output of the solid-state source. In actual use, it is necessary to adjust the loop through software, perform complex debugging and maintenance, and spend more time and cost.

[0004] It can be seen that how to solve the problem of high control cost of microwave solid-state sources is a technical problem that needs to be solved urgently by people in this field. Summary of the invention

[0005] The purpose of the present application is to provide a microwave solid-state source generating circuit to solve the problem of high control cost of the microwave solid-state source.

[0006] In order to solve the above technical problems, the present application provides a microwave solid-state source generating circuit, comprising: Crystal oscillator frequency selection circuit, adjustable attenuation circuit, power amplifier and control circuit, coupling circuit, single chip microcomputer control circuit; The output end of the crystal oscillator frequency selection circuit is connected to the input end of the adjustable attenuation circuit, the output end of the adjustable attenuation circuit is connected to the input end of the power amplification and control circuit, the output end of the power amplification and control circuit is connected to the coupling circuit, and the output end of the coupling circuit serves as the output end of the microwave solid-state source generation circuit; The single-chip microcomputer control circuit is connected to the control end of the crystal oscillator frequency selection circuit, the control end of the adjustable attenuation circuit, and the control end of the power amplification and control circuit; the single-chip microcomputer control circuit controls the crystal oscillator voltage of the crystal oscillator frequency selection circuit, the adjustable attenuator level of the adjustable attenuation circuit, and the on and off of the power amplification and control circuit.

[0007] As an optional solution, in the above microwave solid-state source generating circuit, the crystal oscillator frequency selection circuit includes: a crystal oscillator circuit and a balun circuit; The crystal oscillator circuit comprises: a crystal oscillator, a first capacitor, and a second capacitor; The power supply interface of the crystal oscillator is connected to the single-chip control circuit and grounded through a first capacitor; the ground port of the crystal oscillator is grounded through a second capacitor; the enable pin of the crystal oscillator is connected to a power supply; The balun circuit comprises: a balun transformer, a third capacitor, and a fourth capacitor; The negative clock output terminal of the crystal oscillator is connected to the first input terminal of the balun transformer through a third capacitor; the positive clock output terminal of the crystal oscillator is connected to the second input terminal of the balun transformer through a fourth capacitor, and the output terminal of the balun transformer serves as the output terminal of the crystal oscillator frequency selection circuit.

[0008] As an optional solution, the microwave solid-state source generating circuit further includes: a fourth-order low-pass filter circuit; the output end of the crystal oscillator frequency selection circuit is connected to the input end of the adjustable attenuation circuit through the fourth-order low-pass filter circuit; The fourth-order low-pass filter circuit comprises: a first inductor, a second inductor, a fifth capacitor, and a sixth capacitor; The output end of the crystal oscillator frequency selection circuit is connected to the first end of the first inductor, the second end of the first inductor is connected to the first end of the second inductor and is grounded through the fifth capacitor; the second end of the second inductor is grounded through the sixth capacitor, and the second end of the second inductor is connected to the input end of the adjustable attenuation circuit as the output end of the fourth-order low-pass filter circuit.

[0009] As an optional solution, in the above microwave solid-state source generating circuit, the adjustable attenuation circuit includes: an adjustable attenuator, a seventh capacitor, and a first resistor; The input end of the adjustable attenuator is connected to the output end of the fourth-order low-pass filter circuit, the control end of the adjustable attenuator is grounded through the seventh capacitor, the control end of the adjustable attenuator is connected to the single-chip control circuit through the first resistor, and the output end of the adjustable attenuator serves as the output end of the adjustable attenuation circuit.

[0010] As an optional solution, in the above microwave solid-state source generating circuit, the power amplification and control circuit includes: a power amplification circuit, a power amplifier control circuit; The control end of the power amplifier circuit is connected to the single-chip control circuit, the input end of the power amplifier circuit is connected to the output end of the adjustable attenuation circuit, and the output end of the power amplifier circuit is connected to the input end of the coupling circuit; the output end of the power amplifier circuit is connected to the output end of the power amplifier control circuit, and the control end of the power amplifier control circuit is connected to the single-chip control circuit.

[0011] As an optional solution, in the above microwave solid-state source generating circuit, the power amplifier circuit includes: a first amplifier, a second amplifier, an eighth capacitor, a ninth capacitor, a tenth capacitor, a second resistor, a third resistor, and a fourth resistor; The input end of the first amplifier is connected to the output end of the adjustable attenuation circuit and the first end of the second resistor; the second end of the second resistor is grounded through the eighth capacitor and connected to the single-chip control circuit; the output end of the first amplifier is connected to the first end of the fourth resistor and the input end of the second amplifier; the second end of the fourth resistor is connected to a power supply and grounded through the tenth capacitor; the input end of the second amplifier is connected to the first end of the third resistor; the second end of the third resistor is grounded through the ninth capacitor and connected to the single-chip control circuit; the output end of the second amplifier serves as the output end of the power amplifier circuit.

[0012] As an optional solution, in the above microwave solid-state source generating circuit, the power amplifier control circuit includes: a first transistor, a second transistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, an eleventh capacitor, and a twelfth capacitor; The first end of the first transistor is connected to the first end of the fifth resistor and a power supply; the second end of the fifth resistor is connected to the control end of the first transistor and the first end of the sixth resistor, the second end of the sixth resistor is connected to the first end of the second transistor, the second end of the second transistor is grounded, and the control end of the second transistor is connected to the single-chip control circuit through the seventh resistor; the second end of the first transistor is connected to the first end of the eighth resistor and is grounded through the eleventh capacitor; the second end of the eighth resistor is connected to the output end of the second amplifier and is connected to the input end of the coupling circuit through the twelfth capacitor.

[0013] As an optional solution, in the above microwave solid-state source generating circuit, the coupling circuit includes: a first coupling magnetic ring, a second coupling magnetic ring, a ninth resistor, and a tenth resistor; The first end of the primary coil of the first coupling magnetic ring serves as the input end of the coupling circuit, and the second end of the primary coil of the first coupling magnetic ring is connected to the antenna; the first end of the secondary coil of the first coupling magnetic ring is connected to the first end of the tenth resistor, the second end of the secondary coil of the first coupling magnetic ring is connected to the first end of the ninth resistor, the second end of the ninth resistor and the second end of the tenth resistor are connected to the first end of the primary coil of the second coupling magnetic ring, the second end of the primary coil of the second coupling magnetic ring is grounded, the first end of the secondary coil of the second coupling magnetic ring is connected to the antenna, and the second end of the secondary coil of the second coupling magnetic ring is grounded.

[0014] As an optional solution, the microwave solid-state source generating circuit further includes: a detection circuit; the detection circuit includes: a mean value detector, an eleventh resistor, and a twelfth resistor; The twelfth resistor is connected in parallel between the two ports of the first channel of the mean detector, the eleventh resistor is connected in parallel between the two ports of the second channel of the mean detector, the first end of the secondary coil of the first coupling magnetic ring is connected to the first port of the second channel of the mean detector, the second end of the secondary coil of the first coupling magnetic ring is connected to the first port of the first channel of the mean detector, and the first output port and the second output port of the mean detector are connected to the single-chip control circuit.

[0015] As an optional solution, in the above microwave solid-state source generating circuit, the single-chip control circuit comprises: a micro control unit; The input reverse DC level detection of the microcontroller unit is connected to the first output port of the mean detector, the input forward DC level detection of the microcontroller unit is connected to the second output port of the mean detector, and the voltage output port of the microcontroller unit is connected to the power supply interface of the crystal oscillator; the level control port of the microcontroller unit is connected to the control end of the second transistor through the seventh resistor; the digital-to-analog conversion port of the microcontroller unit is connected to the control end of the adjustable attenuator; the first control end of the microcontroller unit is connected to the second end of the second resistor, and the second control end of the microcontroller unit is connected to the second end of the third resistor.

[0016] The microwave solid-state source generating circuit provided by the present application comprises: a crystal oscillator frequency selection circuit, an adjustable attenuation circuit, a power amplification and control circuit, a coupling circuit, and a single-chip microcomputer control circuit; the output end of the crystal oscillator frequency selection circuit is connected to the input end of the adjustable attenuation circuit, the output end of the adjustable attenuation circuit is connected to the input end of the power amplification and control circuit, the output end of the power amplification and control circuit is connected to the coupling circuit, and the output end of the coupling circuit serves as the output end of the microwave solid-state source generating circuit; the single-chip microcomputer control circuit is connected to the control end of the crystal oscillator frequency selection circuit, the control end of the adjustable attenuation circuit, and the control end of the power amplification and control circuit; the single-chip microcomputer control circuit controls the crystal oscillator voltage of the crystal oscillator frequency selection circuit, the adjustable attenuator level of the adjustable attenuation circuit, and the on-off of the power amplification and control circuit. The present application generates a stable microwave signal through a crystal oscillator frequency selection circuit, adjusts the signal level through an adjustable attenuation circuit, and realizes the frequency selection and preliminary attenuation adjustment of the signal by connecting the crystal oscillator frequency selection circuit and the adjustable attenuation circuit. The signal is amplified through a power amplification and control circuit, and the signal is output through a coupling circuit, thereby realizing the coupled output of the signal. The overall single-chip microcomputer control circuit realizes precise control of the entire circuit, stably controls the output power, and simplifies the system design while being able to realize the microwave radiation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 A schematic diagram of a microwave solid-state source generating circuit is provided for an embodiment of the present application; Figure 2 A circuit diagram of a crystal oscillator circuit and a balun circuit is provided for an embodiment of the present application; Figure 3 A circuit diagram of a fourth-order low-pass filter circuit is provided for an embodiment of the present application; Figure 4 A simulation diagram of a fourth-order low-pass filter provided in an embodiment of the present application Figure 5 A circuit diagram of an adjustable attenuation circuit is provided for an embodiment of the present application; Figure 6 A schematic diagram of an adjustable attenuator curve graph is provided for an embodiment of the present application; Figure 7 A circuit diagram of a power amplifier circuit is provided for an embodiment of the present application; Figure 8 A circuit diagram of a power amplifier control circuit is provided for an embodiment of the present application; Fig. 9 A circuit diagram of a coupling circuit is provided for an embodiment of the present application; FIG10 (a) is a simulation result of a coupling circuit provided in an embodiment of the present application; FIG10( b ) is a simulation result of a coupling circuit provided in an embodiment of the present application; FIG10( c ) is a simulation result of a coupling circuit provided in an embodiment of the present application; FIG10( d ) is a simulation result of a coupling circuit provided in an embodiment of the present application; Fig.11 A circuit diagram of a detection circuit is provided for an embodiment of the present application; Fig.12 A circuit diagram of a single-chip microcomputer control circuit is provided for an embodiment of the present application. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0020] The core of this application is to provide a microwave solid-state source generating circuit.

[0021] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0022] The present application does not limit the application fields of microwave solid-state sources, such as medical field, communication field, radar field, etc.

[0023] In order to solve the above problems, the present invention provides a microwave solid-state source generating circuit. Figure 1 A schematic diagram of a microwave solid-state source generating circuit is provided for an embodiment of the present application, such as Figure 1 As shown, including: Crystal oscillator frequency selection circuit 11, adjustable attenuation circuit 12, power amplification and control circuit 13, coupling circuit 14, single chip microcomputer control circuit 15; The output end of the crystal oscillator frequency selection circuit 11 is connected to the input end of the adjustable attenuation circuit 12, the output end of the adjustable attenuation circuit 12 is connected to the input end of the power amplification and control circuit 13, the output end of the power amplification and control circuit 13 is connected to the coupling circuit 14, and the output end of the coupling circuit 14 serves as the output end of the microwave solid-state source generation circuit; The single-chip microcomputer control circuit 15 is connected to the control end of the crystal oscillator frequency selection circuit 11, the control end of the adjustable attenuation circuit 12, and the control end of the power amplification and control circuit 13; the single-chip microcomputer control circuit 15 controls the crystal oscillator voltage of the crystal oscillator frequency selection circuit 11, the adjustable attenuator level of the adjustable attenuation circuit 12, and the on and off of the power amplification and control circuit 13.

[0024] The crystal oscillator frequency selection circuit 11 refers to a circuit for generating a microwave signal of a specific frequency, and can be specifically designed according to actual needs. The specific microwave signal frequency is not limited in the embodiment of the present application. The crystal oscillator frequency selection circuit 11 outputs a small microwave signal to the adjustable attenuation circuit 12 .

[0025] The adjustable attenuation circuit 12 refers to a circuit part that can adjust the level of the input signal. The specific circuit design can be carried out according to actual needs. The specific adjustable attenuation range is not limited in this embodiment. The output of the adjustable attenuation circuit 12 is the attenuated signal to the power amplification and control circuit 13 to achieve further processing of the signal.

[0026] The power amplifier and control circuit 13 is a circuit that amplifies the signal and controls the on-off, and is used to amplify the small signal level to a high-power signal. The high-power signal after output amplification by the power amplifier and control circuit 13 is connected to the coupling circuit 14 to achieve signal coupling output.

[0027] The coupling circuit 14 refers to a circuit part for coupling forward power and reverse power, ensuring low loss, high coupling degree and high isolation. The output end of the coupling circuit 14 serves as the output end of the microwave solid-state source generation circuit to achieve the final output of the signal.

[0028] The single-chip control circuit 15 refers to the circuit part used to control the entire microwave solid-state source generation circuit, and is responsible for controlling the crystal oscillator voltage, the adjustable attenuator level, and the on-off control of the power amplifier and control circuit 13. The single-chip control circuit 15 is connected to the control end of the crystal oscillator frequency selection circuit 11, the control end of the adjustable attenuation circuit 12, and the control end of the power amplifier and control circuit 13 to achieve precise control of the entire circuit.

[0029] The crystal oscillator voltage refers to the operating voltage of the crystal oscillator, which affects the stability and frequency accuracy of the crystal oscillator output signal.

[0030] The adjustable attenuator level refers to the control voltage of the adjustable attenuator, which affects the level value of the output signal.

[0031] The on and off of the power amplification and control circuit 13 refers to the power supply state of the power amplifier, which affects the amplification and output of the signal.

[0032] The microwave solid-state source generating circuit provided by the embodiment of the present application includes: a crystal oscillator frequency selection circuit 11, an adjustable attenuation circuit 12, a power amplification and control circuit 13, a coupling circuit 14, and a single-chip microcomputer control circuit 15; the output end of the crystal oscillator frequency selection circuit 11 is connected to the input end of the adjustable attenuation circuit 12, the output end of the adjustable attenuation circuit 12 is connected to the input end of the power amplification and control circuit 13, the output end of the power amplification and control circuit 13 is connected to the coupling circuit 14, and the output end of the coupling circuit 14 serves as the output end of the microwave solid-state source generating circuit; the single-chip microcomputer control circuit 15 is connected to the control end of the crystal oscillator frequency selection circuit 11, the control end of the adjustable attenuation circuit 12, and the control end of the power amplification and control circuit 13; the single-chip microcomputer control circuit 15 controls the crystal oscillator voltage of the crystal oscillator frequency selection circuit 11, the adjustable attenuator level of the adjustable attenuation circuit 12, and the on-off of the power amplification and control circuit 13. The present application generates a stable microwave signal through a crystal oscillator frequency selection circuit 11, and adjusts the signal level through an adjustable attenuation circuit 12. The connection between the crystal oscillator frequency selection circuit 11 and the adjustable attenuation circuit 12 realizes the frequency selection and preliminary attenuation adjustment of the signal, amplifies the signal through a power amplification and control circuit 13, and outputs the signal through a coupling circuit 14, thereby realizing the coupled output of the signal. The overall single-chip microcomputer control circuit 15 realizes precise control of the entire circuit, which simplifies the system design while realizing the microwave radiation effect, and realizes precise frequency control and stable output power control.

[0033] According to the above embodiment, in a specific embodiment, the crystal oscillator frequency selection circuit 11 includes: a crystal oscillator circuit, a balun circuit; Figure 2 A schematic diagram of a crystal oscillator circuit and a balun circuit is provided for an embodiment of the present application, such as Figure 2 As shown: The crystal oscillator circuit includes: a crystal oscillator U1, a first capacitor C1, and a second capacitor C2; The power supply interface VF of the crystal oscillator U1 is connected to the single-chip control circuit 15 and is grounded through the first capacitor C1; the ground port of the crystal oscillator U1 is grounded through the second capacitor C2; the enable pin of the crystal oscillator U1 is connected to the power supply; The balun circuit includes: a balun transformer U2, a third capacitor C3, and a fourth capacitor C4; The clock negative output terminal of the crystal oscillator U1 is connected to the first input terminal of the balun transformer U2 through the third capacitor C3; the clock positive output terminal of the crystal oscillator U1 is connected to the second input terminal of the balun transformer U2 through the fourth capacitor C4, and the output terminal of the balun transformer U2 serves as the output terminal of the frequency selection circuit of the crystal oscillator U1.

[0034] The crystal oscillator U1 circuit is the core part for generating a specific frequency signal, including the crystal oscillator U1 itself and two capacitor elements. The crystal oscillator U1 is a frequency control element used to generate an accurate frequency signal. The first capacitor C1 and the second capacitor C2 are used to stabilize the power supply and grounding, and reduce noise and interference. In one implementation, the crystal oscillator U1 specifically refers to the Si550 crystal oscillator, which can output a small microwave signal with a frequency range of 10-945MHz, an operating voltage of +3.3V, and generate a stable small microwave signal of 433MHz. The first capacitor C1 and the second capacitor C2 are used to decouple and stabilize the power supply line, reducing the impact of power supply noise on the operation of the crystal oscillator U1.

[0035] The balun circuit is a balanced-unbalanced conversion circuit, which is used to convert the balanced signal generated by the crystal oscillator U1 circuit into a single-ended signal for subsequent circuit processing. The balun transformer U2 is the core component of the balun circuit, which is used to realize the balanced to unbalanced signal conversion. The selection of the balun transformer U2 needs to consider its operating frequency range and impedance matching to ensure the efficiency of signal conversion and signal integrity. In one implementation scheme, a chip model H3-ETC1-1-13TR is used, which has an operating frequency of 4.5-3000MHz, 50ohm impedance, and a maximum input power of +24dBm. The third capacitor C3 and the fourth capacitor C4 are used to filter out high-frequency noise. The 433MHz microwave small signal becomes a single-ended small signal after the balanced-unbalanced conversion process.

[0036] The enable pin of the crystal oscillator U1 is connected to the power supply, and the working state of the crystal oscillator U1 can be controlled by the level of the enable pin, thereby turning the crystal oscillator U1 on or off. In this embodiment, the single-ended signal after the balun conversion will be used as the output of the frequency selection circuit of the crystal oscillator U1, providing an input signal for the subsequent adjustable attenuation circuit 12.

[0037] According to the above embodiment, in a specific embodiment, it also includes: a fourth-order low-pass filter circuit; the output end of the crystal oscillator U1 frequency selection circuit is connected to the input end of the adjustable attenuation circuit 12 through the fourth-order low-pass filter circuit; Figure 3 A schematic diagram of a fourth-order low-pass filter circuit is provided for an embodiment of the present application, such as Figure 3 As shown: The fourth-order low-pass filter circuit includes: a first inductor L1, a second inductor L2, a fifth capacitor C5, and a sixth capacitor C6; The output end of the crystal oscillator U1 frequency selection circuit is connected to the first end of the first inductor L1, the second end of the first inductor L1 is connected to the first end of the second inductor L2 and is grounded through the fifth capacitor C5; the second end of the second inductor L2 is grounded through the sixth capacitor C6, and the second end of the second inductor L2 is connected to the input end of the adjustable attenuation circuit 12 as the output end of the fourth-order low-pass filter circuit.

[0038] The fourth-order low-pass filter circuit is a circuit used to suppress high-frequency components and allow low-frequency signals to pass through, thereby improving signal quality, reducing spurious signals, and improving system stability. The fourth-order low-pass filter filters out the high-frequency components generated by the crystal oscillator to obtain a 433MHz sine wave.

[0039] Since the crystal oscillator directly generates microwaves at 433MHz, it will also generate many harmonic components, so a low-pass filter must be used to suppress high-frequency components. The 433MHz low-pass filter of the present invention is constructed using fourth-order inductor and capacitor devices. Conventional second-order low-pass filters usually suppress the second or third harmonics by -10 to -15dB, which is relatively low. Although it can be used in a low-pass filter in a phase-locked loop circuit, it is not suitable for this invention. Figure 4 A simulation diagram of a fourth-order low-pass filter provided in an embodiment of the present application is shown in FIG. Figure 4 As shown, this invention introduces a fourth-order low-pass filter, with an insertion loss of less than 1dB at 433MHz and second harmonic suppression close to -30dB, which can effectively suppress the high-order harmonic components brought by the crystal oscillator, reduce system spurious and improve system reliability.

[0040] The first inductor L1 is connected to the output end of the frequency selection circuit of the crystal oscillator U1 to filter out signal components higher than the cutoff frequency while allowing low-frequency signals to pass through. The second inductor L2 is connected in series with the first inductor L1 to further enhance the filtering effect and improve the ability to suppress high-frequency signals. The fifth capacitor C5 works together with the first inductor L1 to filter out high-frequency noise. The sixth capacitor C6 works together with the second inductor L2 to complete the filtering function of the fourth-order low-pass filter circuit.

[0041] The fourth-order low-pass filter circuit can effectively suppress the high-frequency harmonic components generated by the crystal oscillator U1, reduce system spurious, and improve the purity of the signal. Through the coordinated work of multiple inductors and capacitors, the signal quality is improved, providing a more stable input signal for the subsequent adjustable attenuation circuit 12. The impact of high-frequency signals on the system is reduced, and the stability and reliability of the entire microwave solid-state source generation circuit are enhanced.

[0042] According to the above embodiment, in a specific embodiment, Figure 5 A schematic diagram of an adjustable attenuation circuit 12 is provided for an embodiment of the present application, as shown in FIG. Figure 5 As shown, the adjustable attenuation circuit 12 includes: an adjustable attenuator, a seventh capacitor C7, and a first resistor R1; The input terminal RF1 of the adjustable attenuator is connected to the output terminal of the fourth-order low-pass filter circuit, the control terminal of the adjustable attenuator is grounded through the seventh capacitor C7, the control terminal of the adjustable attenuator is connected to the single-chip control circuit 15 (DAC terminal) through the first resistor R1, and the output terminal RF3 of the adjustable attenuator serves as the output terminal of the adjustable attenuation circuit 12.

[0043] The adjustable attenuator is a key component in the circuit for adjusting the degree of signal attenuation. The attenuation value of the signal can be dynamically adjusted according to the control signal. The input end is connected to the output end of the fourth-order low-pass filter circuit to receive the filtered signal. The control end receives the control signal from the single-chip control circuit 15 to adjust the working state of the attenuator, thereby changing the level of the output signal.

[0044] The seventh capacitor C7 is connected between the control terminal of the adjustable attenuator and the ground, and is used for decoupling and stabilizing the control signal, thereby reducing the influence of noise on the control signal.

[0045] The input end of the adjustable attenuator is connected to the output end of the fourth-order low-pass filter circuit, ensuring that the filtered signal can be accurately adjusted. The control end of the adjustable attenuator is connected to the single-chip control circuit 15 through the first resistor R1, so that the single-chip microcomputer dynamically adjusts the working state of the attenuator according to system requirements.

[0046] Figure 6 A schematic diagram of an adjustable attenuator curve diagram is provided for an embodiment of the present application, such as Figure 6 As shown, when the control voltage DAC is 0.6V, the attenuation value is close to 0, and the output signal level is maximum at this time. When the control voltage DAC is 2.0V, the attenuation value reaches -35dB, and the output signal level is minimum at this time.

[0047] The attenuation degree of the signal is dynamically adjusted through the adjustable attenuator according to actual needs, which improves the flexibility and adaptability of the system.

[0048] According to the above embodiment, in a specific embodiment, the power amplification and control circuit 13 includes: a power amplifier circuit, a power amplifier control circuit; The control end of the power amplifier circuit is connected to the single-chip control circuit 15, the input end of the power amplifier circuit is connected to the output end of the adjustable attenuation circuit 12, and the output end of the power amplifier circuit is connected to the input end of the coupling circuit 14; the output end of the power amplifier circuit is connected to the output end of the power amplifier control circuit, and the control end of the power amplifier control circuit is connected to the single-chip control circuit 15.

[0049] Power amplifier circuit This is the circuit part used to amplify the signal to the required power level. The control end is connected to the single-chip control circuit 15, and receives the control signal to adjust the working state of the power amplifier, such as the amplifier on, off or working mode. The input end is connected to the output end of the adjustable attenuation circuit 12 to receive the attenuated signal. The output end is connected to the input end of the coupling circuit 14 to pass the amplified signal to the coupling circuit 14.

[0050] The power amplifier control circuit is used to control the working state of the power amplifier to ensure that the power amplifier can work safely and effectively according to system requirements. The control end is connected to the single chip control circuit 15 and receives a control signal to control on and off.

[0051] By connecting the single chip control circuit 15 to the control terminal of the power amplifier circuit, dynamic power control of the power amplifier can be achieved, improving the flexibility and efficiency of the system. The power amplifier control circuit controls the on and off of the power amplifier circuit to prevent damage caused by overload or other abnormal conditions.

[0052] According to the above embodiment, in a specific embodiment, Figure 7 A schematic diagram of a power amplifier circuit is provided for an embodiment of the present application, such as Figure 7 As shown, the power amplifier circuit includes: a first amplifier U4, a second amplifier U5, an eighth capacitor C8, a ninth capacitor C9, a tenth capacitor C10, a second resistor R2, a third resistor R3, and a fourth resistor R4; The input end of the first amplifier U4 is connected to the output end of the adjustable attenuation circuit 12 and the first end of the second resistor R2; the second end of the second resistor R2 is grounded through the eighth capacitor C8 and connected to the single-chip control circuit 15 (VGS1 end); the output end of the first amplifier U4 is connected to the first end of the fourth resistor R4 and the input end of the second amplifier U5; the second end of the fourth resistor R4 is connected to the power supply and grounded through the tenth capacitor C10; the input end of the second amplifier U5 is connected to the first end of the third resistor R3; the second end of the third resistor R3 is grounded through the ninth capacitor C9 and connected to the single-chip control circuit 15 (VGS2 end); the output end of the second amplifier U5 serves as the output end of the power amplifier circuit.

[0053] The first amplifier U4 of the power amplifier circuit is the first amplification stage in the power amplifier circuit, and the second amplifier U5 is the second amplification stage in the power amplifier circuit.

[0054] The input end of the first amplifier U4 is connected to the output end of the adjustable attenuation circuit 12 and the first end of the second resistor R2 to ensure that the signal can be received and amplified by the first amplifier U4.

[0055] The second end of the second resistor R2 is grounded through the eighth capacitor C8 and connected to the single-chip control circuit 15. The single-chip control circuit 15 can dynamically adjust the working state of the first amplifier U4.

[0056] The input end of the second amplifier U5 is connected to the first end of the third resistor R3, and receives the signal amplified by the first amplifier U4. The second end of the third resistor R3 is grounded through the ninth capacitor C9 and connected to the single-chip control circuit 15, and the single-chip control circuit 15 can dynamically adjust the working state of the second amplifier U5. The output end of the second amplifier U5 serves as the output end of the power amplifier circuit to provide the final amplified signal.

[0057] Through the design of two-stage amplifier, the power level of the signal can be significantly improved to meet the needs of high-power output. The two-stage power amplifier is added after the adjustable attenuator, mainly to amplify the small signal level. In one implementation scheme, the two-stage amplifiers use BLP0427M9S20 and BLF647P respectively. BLP0427M9S20 is used as a driver amplifier, with an operating frequency of 400-2700MHz, an output power of up to 20W, a signal gain of about 19dB, a drain operating voltage of +28V, and a gate operating voltage of about 2.1V. It is a lateral diffused metal oxide semiconductor (LDMOS) high linearity power amplifier with an efficiency greater than 50%. BLF647P is used as a power amplifier. Its main function is to provide high-power output signals. The output power can reach 200W, the operating frequency is 30-1500MHz, the signal gain is about 18dB, the drain operating voltage can reach +32V, and the gate operating voltage is about 1.8V.

[0058] According to the above embodiment, in a specific embodiment, Figure 8 A circuit diagram of a power amplifier control circuit is provided for an embodiment of the present application, such as Figure 8 As shown, the power amplifier control circuit includes: a first transistor Q1, a second transistor Q2, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, an eleventh capacitor C11, and a twelfth capacitor C12; The first end of the first transistor Q1 is connected to the first end of the fifth resistor R5 and the power supply (power supply +28V); the second end of the fifth resistor R5 is connected to the control end of the first transistor Q1 and the first end of the sixth resistor R6, the second end of the sixth resistor R6 is connected to the first end of the second transistor Q2, the second end of the second transistor Q2 is grounded, and the control end of the second transistor Q2 is connected to the single-chip control circuit 15 (RF_ON) through the seventh resistor R7; the second end of the first transistor Q1 is connected to the first end of the eighth resistor R8 and is grounded through the eleventh capacitor C11; the second end of the eighth resistor R8 is connected to the output end of the second amplifier U5 and is connected to the input end of the coupling circuit 14 through the twelfth capacitor C12.

[0059] The first end of the first transistor Q1 is directly connected to the power supply, and is connected to the power supply through the fifth resistor R5, ensuring that the transistor can receive the power supply voltage. The control end of the first transistor Q1 is connected to the sixth resistor R6 through the fifth resistor R5, receives a control signal from the single-chip control circuit 15, and adjusts the conduction state of the transistor. The first end of the second transistor Q2 is connected to the control end of the first transistor Q1 through the sixth resistor R6, and the second end is grounded. The control end is connected to the single-chip control circuit 15 through the seventh resistor R7 for receiving the control signal. The control end RF_ON controls the on and off of the power amplifier power supply +28V. When RF_ON is high level, the power amplifier works, and when RF_ON is low level, the power amplifier is turned off and does not work.

[0060] According to the above embodiment, in a specific embodiment, Fig. 9 A circuit diagram of a coupling circuit 14 is provided for an embodiment of the present application, such as Fig. 9 As shown, the coupling circuit 14 includes: a first coupling magnetic ring T1, a second coupling magnetic ring T2, a ninth resistor R9, and a tenth resistor R10; The first end of the primary coil of the first coupling magnetic ring T1 serves as the input end of the coupling circuit 14, and the second end of the primary coil of the first coupling magnetic ring T1 is connected to the antenna; the first end of the secondary coil of the first coupling magnetic ring T1 is connected to the first end of the tenth resistor R10, the second end of the secondary coil of the first coupling magnetic ring T1 is connected to the first end of the ninth resistor R9, the second end of the ninth resistor R9 and the second end of the tenth resistor R10 are connected to the first end of the primary coil of the second coupling magnetic ring T2, the second end of the primary coil of the second coupling magnetic ring T2 is grounded, the first end of the secondary coil of the second coupling magnetic ring T2 is connected to the antenna, and the second end of the secondary coil of the second coupling magnetic ring T2 is grounded.

[0061] The output of the power amplifier circuit is connected in series with a coupling circuit 14, and the coupling circuit 14 uses a first coupling magnetic ring T1 and a second coupling magnetic ring T2 for coupling to ensure low loss, high coupling, high isolation, and high directivity. The coupling circuit 14 is quite different from the conventional microstrip coupling circuit 14. The microstrip coupling has a relatively long microstrip line at 433MHz, occupies a large circuit board area, and has poor directivity, generally only about -10dB. The coupling circuit 14 used in the present invention adopts a magnetic ring structure, has a small size, occupies a small circuit board area, and can mainly achieve high directivity, achieve high isolation of forward and reverse power, and can be accurately changed according to the size of the forward and reverse power.

[0062] Figure 10 (a) is a simulation result of a coupling circuit 14 provided in an embodiment of the present application; Figure 10 (b) is a simulation result of a coupling circuit 14 provided in an embodiment of the present application; Figure 10 (c) is a simulation result of a coupling circuit 14 provided in an embodiment of the present application; Figure 10 (d) is a simulation result of a coupling circuit 14 provided in an embodiment of the present application; as shown in Figures 10 (a), 10 (b), 10 (c), and 10 (d), the insertion loss introduced by the directional coupler is -0.018dB, the forward coupling degree is close to -27dB, the isolation degree is -57dB, and the directivity is about 30dB, which avoids interference between forward and reverse signals caused by poor directivity and also ensures the accuracy of forward and reverse power detection.

[0063] According to the above embodiment, in a specific embodiment, it further includes: a detection circuit 16; Fig.11 A circuit diagram of a detection circuit 16 is provided for an embodiment of the present application, as shown in FIG. Fig.11 As shown, the detection circuit 16 includes: a mean value detector U6, an eleventh resistor R11, and a twelfth resistor R12; The twelfth resistor R12 is connected in parallel between the two ports of the first channel of the mean detector U6, the eleventh resistor R11 is connected in parallel between the two ports of the second channel of the mean detector U6, the first end of the secondary coil of the first coupling magnetic ring T1 is connected to the first port of the second channel of the mean detector U6, the second end of the secondary coil of the first coupling magnetic ring T1 is connected to the first port of the first channel of the mean detector U6, and the first output port (RF_R) and the second output port (RF_F) of the mean detector U6 are connected to the single-chip control circuit 15.

[0064] The insertion loss introduced by the directional coupler is -0.018dB, the forward coupling is close to -27dB, the isolation is -57dB, and the directivity is about 30dB, which avoids interference between forward and reverse signals caused by poor directivity and ensures the accuracy of forward and reverse power detection. The forward and reverse voltage detection outputs are respectively connected to PI-type attenuation to adjust the coupling power, and then power detection is performed to output the forward and reverse power voltage values. The mean detector U6LTC5583 used in the detection circuit 16 is a dual-channel mean detector U6 that supports 40-6000MHz, with a dynamic range of 60dB and a detectable level range of -55dBm~+5dBm. It outputs a DC voltage of 0.6V~2.4V within the detectable level range and an operating voltage of +3.3V. According to the above embodiment, in a specific embodiment, Fig.12 A circuit diagram of a single chip control circuit 15 is provided for an embodiment of the present application, such as Fig.12 As shown, the single chip control circuit 15 includes: a micro control unit U7; The input reverse DC level detection RF_R of the microcontroller unit U7 is connected to the first output port of the mean detector U6, the input forward DC level detection RF_F of the microcontroller unit U7 is connected to the second output port of the mean detector U6, and the voltage output port VF of the microcontroller unit U7 is connected to the power supply interface of the crystal oscillator U1; the level control port RF_ON of the microcontroller unit U7 is connected to the control end of the second transistor Q2 through the seventh resistor R7; the digital-to-analog conversion port DAC of the microcontroller unit U7 is connected to the control end of the adjustable attenuator; the first control end VGS1 of the microcontroller unit U7 is connected to the second end of the second resistor R2, and the second control end VGS2 of the microcontroller unit U7 is connected to the second end of the third resistor R3.

[0065] The microcontroller in the microcontroller control circuit 15 can be selected from GD32F103RET6, which operates at an operating voltage of 2.6 V to 3.6 V and a temperature range of -40°C to +85°C, and provides up to three 12-bit ADCs (analog-to-digital conversion). It is mainly used for sampling of positive and negative DC level values ​​and power amplifier power supply control. RF_R is the reverse DC level detection of the microcontroller input, RF_F is the positive DC voltage detection of the microcontroller input, RF_ON is the microcontroller output control power amplifier power supply, VF crystal oscillator U1 controls the voltage, DAC controls the adjustable attenuator level, controls the attenuation value, and thus controls the final output power. VGS1 and VGS2 are the gate voltages of the control amplifier to adjust the static operating point of the power amplifier. Fig.12 It is the power amplifier control circuit. The MCU control pin RF_ON controls the on / off of the power amplifier power supply +28V. When RF_ON is high level, the power amplifier works. When RF_ON is low level, the power amplifier is turned off and does not work.

[0066] The size of the RF_R reverse detection level determines the size of the reflected power of the power amplifier. When the reflected power is greater than a certain value, that is, RF_R is greater than a certain voltage value, the microcontroller triggers the RF_ON low level, thereby shutting down the power amplifier for protection.

[0067] The size of the RF_F forward detection level determines the size of the forward power of the power amplifier. Different power levels have different RF_F detection level values. The microcontroller can detect the output power size based on the RF_F level size, and can control the size of the DAC value to adjust the output power size.

[0068] The microwave solid-state source generating circuit provided by the present application is introduced in detail above. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

[0069] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

Claims

1. A microwave solid-state source generating circuit, characterized in that: include: Crystal oscillator frequency selection circuit, adjustable attenuation circuit, power amplifier and control circuit, coupling circuit, single chip microcomputer control circuit; The output end of the crystal oscillator frequency selection circuit is connected to the input end of the adjustable attenuation circuit, the output end of the adjustable attenuation circuit is connected to the input end of the power amplification and control circuit, the output end of the power amplification and control circuit is connected to the coupling circuit, and the output end of the coupling circuit serves as the output end of the microwave solid-state source generation circuit; The single-chip microcomputer control circuit is connected to the control end of the crystal oscillator frequency selection circuit, the control end of the adjustable attenuation circuit, and the control end of the power amplification and control circuit; the single-chip microcomputer control circuit controls the crystal oscillator voltage of the crystal oscillator frequency selection circuit, the adjustable attenuator level of the adjustable attenuation circuit, and the on and off of the power amplification and control circuit.

2. The microwave solid-state source generating circuit according to claim 1, characterized in that: The crystal oscillator frequency selection circuit comprises: a crystal oscillator circuit and a balun circuit; The crystal oscillator circuit comprises: a crystal oscillator, a first capacitor, and a second capacitor; The power supply interface of the crystal oscillator is connected to the single-chip control circuit and grounded through a first capacitor; the ground port of the crystal oscillator is grounded through a second capacitor; the enable pin of the crystal oscillator is connected to a power supply; The balun circuit comprises: a balun transformer, a third capacitor, and a fourth capacitor; The negative clock output terminal of the crystal oscillator is connected to the first input terminal of the balun transformer through a third capacitor; the positive clock output terminal of the crystal oscillator is connected to the second input terminal of the balun transformer through a fourth capacitor, and the output terminal of the balun transformer serves as the output terminal of the crystal oscillator frequency selection circuit.

3. The microwave solid-state source generating circuit according to claim 2, characterized in that: Also includes: Fourth-order low-pass filter circuit; The output end of the crystal oscillator frequency selection circuit is connected to the input end of the adjustable attenuation circuit through the fourth-order low-pass filter circuit; The fourth-order low-pass filter circuit comprises: a first inductor, a second inductor, a fifth capacitor, and a sixth capacitor; The output end of the crystal oscillator frequency selection circuit is connected to the first end of the first inductor, the second end of the first inductor is connected to the first end of the second inductor and is grounded through the fifth capacitor; the second end of the second inductor is grounded through the sixth capacitor, and the second end of the second inductor is connected to the input end of the adjustable attenuation circuit as the output end of the fourth-order low-pass filter circuit.

4. The microwave solid-state source generating circuit according to claim 3, characterized in that: The adjustable attenuation circuit comprises: an adjustable attenuator, a seventh capacitor, and a first resistor; The input end of the adjustable attenuator is connected to the output end of the fourth-order low-pass filter circuit, the control end of the adjustable attenuator is grounded through the seventh capacitor, the control end of the adjustable attenuator is connected to the single-chip control circuit through the first resistor, and the output end of the adjustable attenuator serves as the output end of the adjustable attenuation circuit.

5. The microwave solid-state source generating circuit according to claim 4, characterized in that: The power amplification and control circuit comprises: a power amplification circuit and a power amplifier control circuit; The control end of the power amplifier circuit is connected to the single-chip control circuit, the input end of the power amplifier circuit is connected to the output end of the adjustable attenuation circuit, and the output end of the power amplifier circuit is connected to the input end of the coupling circuit; the output end of the power amplifier circuit is connected to the output end of the power amplifier control circuit, and the control end of the power amplifier control circuit is connected to the single-chip control circuit.

6. The microwave solid-state source generating circuit according to claim 5, characterized in that: The power amplifier circuit comprises: a first amplifier, a second amplifier, an eighth capacitor, a ninth capacitor, a tenth capacitor, a second resistor, a third resistor, and a fourth resistor; The input end of the first amplifier is connected to the output end of the adjustable attenuation circuit and the first end of the second resistor; the second end of the second resistor is grounded through the eighth capacitor and connected to the single-chip control circuit; the output end of the first amplifier is connected to the first end of the fourth resistor and the input end of the second amplifier; the second end of the fourth resistor is connected to a power supply and grounded through the tenth capacitor; the input end of the second amplifier is connected to the first end of the third resistor; the second end of the third resistor is grounded through the ninth capacitor and connected to the single-chip control circuit; the output end of the second amplifier serves as the output end of the power amplifier circuit.

7. The microwave solid-state source generating circuit according to claim 6, characterized in that: The power amplifier control circuit comprises: a first transistor, a second transistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, an eleventh capacitor, and a twelfth capacitor; The first end of the first transistor is connected to the first end of the fifth resistor and a power supply; the second end of the fifth resistor is connected to the control end of the first transistor and the first end of the sixth resistor, the second end of the sixth resistor is connected to the first end of the second transistor, the second end of the second transistor is grounded, and the control end of the second transistor is connected to the single-chip control circuit through the seventh resistor; the second end of the first transistor is connected to the first end of the eighth resistor and is grounded through the eleventh capacitor; the second end of the eighth resistor is connected to the output end of the second amplifier and is connected to the input end of the coupling circuit through the twelfth capacitor.

8. The microwave solid-state source generating circuit according to claim 7, characterized in that: The coupling circuit comprises: a first coupling magnetic ring, a second coupling magnetic ring, a ninth resistor, and a tenth resistor; The first end of the primary coil of the first coupling magnetic ring serves as the input end of the coupling circuit, and the second end of the primary coil of the first coupling magnetic ring is connected to the antenna; the first end of the secondary coil of the first coupling magnetic ring is connected to the first end of the tenth resistor, the second end of the secondary coil of the first coupling magnetic ring is connected to the first end of the ninth resistor, the second end of the ninth resistor and the second end of the tenth resistor are connected to the first end of the primary coil of the second coupling magnetic ring, the second end of the primary coil of the second coupling magnetic ring is grounded, the first end of the secondary coil of the second coupling magnetic ring is connected to the antenna, and the second end of the secondary coil of the second coupling magnetic ring is grounded.

9. The microwave solid-state source generating circuit according to claim 8, characterized in that: Also includes: Detection circuit; The detection circuit comprises: a mean value detector, an eleventh resistor, and a twelfth resistor; The twelfth resistor is connected in parallel between the two ports of the first channel of the mean detector, the eleventh resistor is connected in parallel between the two ports of the second channel of the mean detector, the first end of the secondary coil of the first coupling magnetic ring is connected to the first port of the second channel of the mean detector, the second end of the secondary coil of the first coupling magnetic ring is connected to the first port of the first channel of the mean detector, and the first output port and the second output port of the mean detector are connected to the single-chip control circuit.

10. The microwave solid-state source generating circuit according to claim 9, characterized in that: The single chip control circuit comprises: a micro control unit; The input reverse DC level detection of the microcontroller unit is connected to the first output port of the mean detector, the input forward DC level detection of the microcontroller unit is connected to the second output port of the mean detector, and the voltage output port of the microcontroller unit is connected to the power supply interface of the crystal oscillator; the level control port of the microcontroller unit is connected to the control end of the second transistor through the seventh resistor; the digital-to-analog conversion port of the microcontroller unit is connected to the control end of the adjustable attenuator; the first control end of the microcontroller unit is connected to the second end of the second resistor, and the second control end of the microcontroller unit is connected to the second end of the third resistor.

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