Switch limiter low noise amplifier

Abstract

The utility model relates to the technical field of microwave communication, in particular to a switch amplitude limiter low-noise amplifier which comprises an attenuation circuit, an amplitude limiting circuit, a filter circuit, an amplifying circuit, a noise reduction circuit and a processor. The amplitude limiting circuit comprises a fixed amplitude limiting circuit and a dynamic amplitude limiting circuit, the dynamic amplitude limiting circuit comprises a field effect transistor, and the processor sends a signal to the field effect transistor to control a switch of the field effect transistor, so that amplitude limiting parameters in the amplitude limiting circuit can be dynamically adjusted; the amplifying circuit comprises a digital-to-analog converter, and analog signals output by the digital-to-analog converter are used for simulating the function of a potentiometer, so that the gain of the amplifying circuit is changed. According to the utility model, the technical problem that the amplitude limiting parameter and the amplification factor cannot be dynamically adjusted in the existing amplitude limiting low-noise amplifier is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of microwave communication, in particular to a switch limiter low noise amplifier. Background Art

[0002] The low noise amplifier is an indispensable step in the microwave signal processing circuit. It mainly amplifies the received microwave signal and minimizes the introduction of noise so that the subsequent circuit can analyze the amplified microwave signal. However, if the microwave signal with too high power directly enters the low noise amplifier, it is easy to cause the low noise amplifier to overload, thereby causing the internal components of the low noise amplifier to be damaged. Therefore, it is extremely important to study how the microwave signal can enter the low noise amplifier with appropriate power.

[0003] The Chinese utility model patent with the name of "A Switch Limiting Low Noise Amplifier" and publication number CN204836091U has been published. It includes a single-pole double-throw switch unit, a high-power resistor, a limiter, and an amplifier circuit. The utility model patent integrates the switch limiter and the low-noise amplifier into an integrated design so that the microwave signal can enter the low-noise amplifier with appropriate power. However, the patent cannot dynamically adjust the limiting parameters and amplification factor. Not only can it not adapt to a variety of application scenarios, but it also cannot maintain the best signal processing effect. Utility Model Content

[0004] The purpose of the present application is to provide a switch limiter low noise amplifier, which solves the technical problem that the limiting parameters and the amplification factor cannot be dynamically adjusted in the existing limiting low noise amplifier.

[0005] In order to solve the above technical problems, the solution adopted by this application is as follows:

[0006] The utility model provides a switch limiter low noise amplifier, comprising a limiter circuit, an amplifier circuit connected to the limiter circuit, and a noise reduction circuit connected to the amplifier circuit, and is characterized in that: a processor is also included, the processor is respectively connected to the limiter circuit, the amplifier circuit, and the noise reduction circuit, the signal output by the noise reduction circuit is transmitted to the processor, and after the processor receives the signal, it is analyzed and processed and sent to the limiter circuit or the amplifier circuit; the limiter circuit comprises a fixed limiter circuit and a dynamic limiter circuit;

[0007] The processor includes a single chip microcomputer, and the single chip microcomputer is respectively connected to the dynamic limiting circuit and the amplifying circuit;

[0008] The dynamic limiting circuit includes a field effect transistor, the gate of the field effect transistor is connected to the single chip microcomputer in the processor, and the single chip microcomputer sends a signal to the field effect transistor to control the switch of the field effect transistor;

[0009] The amplifier circuit includes a digital-to-analog converter circuit, which includes a digital-to-analog converter. The digital-to-analog converter is connected to the single-chip microcomputer. The digital-to-analog converter receives a signal sent by the single-chip microcomputer and outputs a voltage to the amplifier circuit after conversion.

[0010] In some embodiments, the fixed amplitude limiting circuit includes a normal diode and a Schottky diode, and the normal diode and the Schottky diode are connected in parallel.

[0011] In some embodiments, an attenuation circuit is also included, wherein the input end of the attenuation circuit receives a microwave signal, and after attenuation processing by the attenuation circuit, the attenuation circuit sends the processed microwave signal to a limiting circuit connected thereto.

[0012] In some embodiments, a filtering circuit is also included. After receiving a signal sent by a limiting circuit connected to the filtering circuit, the filtering circuit processes the signal, and after the processing is completed, sends the signal to an amplifying circuit connected to the filtering circuit.

[0013] In some embodiments, the filter circuit is an LC filter circuit, and the LC filter circuit includes an inductor and a capacitor, and the inductor and the capacitor are connected in parallel.

[0014] In some embodiments, the dynamic limiting circuit further includes a diode connected to the drain of the field effect transistor.

[0015] In some embodiments, a power supply module is also included, and the power supply module is connected to the processor, the amplifying circuit, and the noise reduction circuit respectively.

[0016] In some embodiments, the digital-to-analog converter is DAC8830IDR.

[0017] In some embodiments, the model of the single chip microcomputer is STM32F103C8T6.

[0018] The technical solution of the present application has at least the following advantages and beneficial effects:

[0019] 1. The utility model can dynamically adjust the parameters of the limiting circuit and the amplifying circuit according to the parameters set by the staff, can adapt to a variety of application scenarios, and can achieve different functional requirements without changing the hardware. In the process of processing signals, the dynamic adjustment of circuit parameters can maintain the best signal processing effect;

[0020] 2. The amplifier circuit of the utility model is provided with a digital-to-analog converter, and the analog signal output by the digital-to-analog converter simulates the function of the potentiometer, thereby changing the gain of the amplifier circuit, thereby achieving the effect of amplifying the amplifier circuit by different multiples. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a signal processing flow chart of the utility model;

[0022] Figure 2 It is the circuit principle diagram of the utility model;

[0023] Figure 3 The figure is a schematic diagram of a digital-to-analog converter circuit in the amplifier circuit of the utility model. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0025] It should be noted that similar numbers and letters represent similar items in the following figures, so once an item is defined in one figure, it does not need to be further defined and explained in the subsequent figures. If the terms "center", "upper", "lower", "inner", "outer", etc. indicate an orientation or position relationship based on the orientation or position relationship shown in the figure, or the orientation or position relationship in which the product of the application is usually placed when in use, it is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present application. It should also be noted that unless otherwise clearly specified and limited, if the terms "set", "install", and "connect" appear, they should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be a connection between the two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0026] Example 1

[0027] Please refer to Figure 1-Figure 3The utility model provides a switch limiter low-noise amplifier, which is the same as the prior art and includes an attenuation circuit, a limiting circuit, an amplifying circuit, and a noise reduction circuit; the attenuation circuit is connected to the limiting circuit, and after receiving a microwave signal, the attenuation circuit processes the microwave signal, and outputs the signal to the limiting circuit after the processing is completed; after receiving the signal and completing the limiting operation, the limiting circuit transmits the signal to the amplifying circuit connected thereto, and after completing the amplifying operation, the amplifying circuit outputs the signal to the noise reduction circuit connected thereto, and the noise reduction circuit performs noise reduction processing on the received signal, and outputs the signal after the processing is completed.

[0028] In this embodiment, a filtering circuit is also included. The filtering circuit is arranged at the connection between the limiting circuit and the amplifying circuit. After receiving the output signal of the limiting circuit, the filtering circuit filters the signal to complete preliminary noise reduction. After the processing is completed, the signal is sent to the amplifying circuit, and the amplifying circuit performs corresponding processing operations. In this embodiment, the filtering circuit is an LC filtering circuit.

[0029] Different from the prior art, the present invention further comprises a processor, the processor comprises a single chip microcomputer, and the single chip microcomputer is respectively connected to the limiter circuit, the amplifier circuit, and the noise reduction circuit; the single chip microcomputer obtains the output signal from the noise reduction circuit, compares the signal with the signal parameter set by the staff, and sends the signal to the limiter circuit and the amplifier circuit respectively according to the comparison result, and dynamically adjusts the limiter parameters of the limiter circuit and the amplification factor of the amplifier circuit; in this embodiment, the model of the single chip microcomputer is STM32F103C8T6;

[0030] In this embodiment, the amplitude limiting circuit includes a fixed amplitude limiting circuit and a dynamic amplitude limiting circuit. The dynamic amplitude limiting circuit includes a field effect transistor and a diode. The field effect transistor is connected to the single chip microcomputer and the diode respectively. The single chip microcomputer controls the field effect transistor to turn on and off, thereby adjusting the amplitude limiting parameters of the amplitude limiting circuit. The diode is used to enhance the amplitude limiting capability of the dynamic amplitude limiting circuit. The fixed amplitude limiting circuit is provided with an ordinary diode and a Schottky diode. The purpose of mixing these two diodes is to balance cost and performance and achieve higher overall efficiency.

[0031] It should be noted that in this embodiment, the dynamic limiter circuit is provided with two field effect transistors, which serve as a basic dynamic limiter circuit. According to actual conditions, several basic dynamic limiter circuits can be connected in parallel to increase the limiter range.

[0032] In this embodiment, the amplifier circuit includes a digital-to-analog converter circuit, in which a digital-to-analog converter is provided. The purpose is to use the analog signal output by the digital-to-analog converter to simulate the function of the potentiometer and then change the gain of the amplifier circuit, thereby achieving the effect of amplifying the amplifier circuit by different multiples; the model of the digital-to-analog converter is DAC8830IDR.

[0033] The circuit in this embodiment includes a digital-to-analog converter U1, a transistor Q7, field effect transistors Q1, Q2, Q3, Q4, Q5, Q6, capacitors C1, C2, C3, C4, C5, an inductor L1, ordinary diodes D1, D2, D5, D6, Schottky diodes D3, D4, resistors R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13; the attenuation circuit includes resistors R1, R2, R3, R4; the fixed limiter circuit includes ordinary diodes D1, D2, and Schottky diodes D3, D4. The dynamic limiting circuit includes field effect transistors Q1, Q2, and ordinary diodes D5, D6; the amplifier circuit includes a digital-to-analog converter U1, a transistor Q6, a field effect transistor Q3, Q4, capacitors C2, C5, and resistors R5, R6, R10, R11, R12, and R13; the digital-to-analog converter circuit in the amplifier circuit includes a digital-to-analog converter U1, a transistor Q6, a capacitor C5, and resistors R10, R11, R12, and R13; the noise reduction circuit includes field effect transistors Q5, Q6, capacitors C3, C4, and resistors R7, R8, and R9.

[0034] Further, one end of the resistor R1 is connected to one end of the resistor R2, and a port is set at the connection as an IN end for receiving an initial microwave signal; the other end of the resistor R1 is grounded, the other end of the resistor R2, one end of the resistor R3, and one end of the resistor R4 are connected, the other end of the resistor R3 is grounded, the other end of the resistor R4, the cathode of the common diode D1, the anode of the common diode D2, the cathode of the Schottky diode D3, the anode of the Schottky diode D4, the cathode of the common diode D5, the anode of the common diode D6, one end of the inductor L1, and one end of the capacitor C1 are connected, and the anode of the common diode D1 is connected to The cathode of the common diode D2 is grounded, the anode of the Schottky diode D3 is grounded, the cathode of the Schottky diode D4 is grounded, and the other end of the inductor L1 is grounded; the anode of the common diode D5 is connected to the D end (drain) of the field effect transistor Q1, the S end (source) of the field effect transistor Q1 is grounded, and the G end (gate) of the field effect transistor Q1 is connected to the PA4 pin of the single chip microcomputer; the cathode of the common diode D6 is connected to the D end (drain) of the field effect transistor Q2, the S end (source) of the field effect transistor Q2 is grounded, and the G end (gate) of the field effect transistor Q2 is connected to the PA3 pin of the single chip microcomputer ; The other end of the capacitor C1 is connected to the G end of the field effect transistor Q3, the S end of the field effect transistor Q3 is grounded, the D end of the field effect transistor Q3, one end of the resistor R5, and one end of the capacitor C2 are connected, and the other end of the resistor R5 is set to the A end for receiving the voltage output by the digital-to-analog conversion circuit; the other end of the capacitor C2 is connected to the G end of the field effect transistor Q4, the S end of the field effect transistor Q4 is grounded, the D end of the field effect transistor Q4, one end of the resistor R6, and one end of the capacitor C3 are connected, and the other end of the resistor R6 is set to the B end for receiving the voltage output by the digital-to-analog conversion circuit; the other end of the capacitor C3 It is connected to the G end of the field effect transistor Q5, the S end of the field effect transistor Q5, the S end of the field effect transistor Q6, and one end of the resistor R9, and the other end of the resistor R9 is connected to the negative power supply; the D end of the field effect transistor Q5 is connected to one end of the resistor R7, and an output end is set at this connection, and it is called the OUT end, which is used to output the processed microwave signal; the other end of the resistor R7 is connected to one end of the resistor R8 and connected to the power supply, the other end of the resistor R8 is connected to the D end of the field effect transistor Q6, the G end of the field effect transistor Q6 is connected to one end of the capacitor C4, and the other end of the capacitor C4 is grounded.

[0035] Furthermore, in the digital-to-analog converter circuit, the base of the transistor Q6 is connected to the PA6 pin of the single-chip microcomputer, the collector of the transistor Q7 is connected to one end of the resistor R12 and connected to the power supply, the emitter of the transistor Q7 is connected to one end of the resistor R11, the other end of the resistor R12, one end of the resistor R13, the other end of the resistor R11, and the VREF end of the digital-to-analog converter U1 are connected, and the other end of the resistor R13 is connected to the AGND end of the digital-to-analog converter U1 and grounded; the CS# end, SDI end, and SCLK end of the digital-to-analog converter U1 are respectively connected to the PA5 pin, SDA pin, and SCL pin of the single-chip microcomputer, the VDD end of the digital-to-analog converter U1 is connected to one end of the resistor R10, the other end of the resistor R10 is connected to one end of the capacitor C5 and connected to the power supply, and the other end of the capacitor C5 is connected to the DGND end of the digital-to-analog converter U1 and grounded; the VOUT end of the digital-to-analog converter U1 is connected to the A end or the B end in the amplifier circuit. The function of capacitor C1 is filtering, and its purpose is to stabilize the voltage; the microcontroller can send a signal to the digital-to-analog converter circuit through the PA6 pin, thereby adjusting the output voltage of the digital-to-analog converter circuit.

[0036] So far, various embodiments of the present invention have been described in detail. In order to avoid obscuring the concept of the present invention, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution of the present invention, and the scope of the present invention is defined by the attached claims.

Claims

1. A switching limiter low noise amplifier, comprising a limiter circuit, an amplifier circuit connected to the limiter circuit, and a noise reduction circuit connected to the amplifier circuit, characterized in that: It also includes a processor, which is connected to the limiting circuit, the amplifying circuit, and the noise reduction circuit respectively. The signal output by the noise reduction circuit is transmitted to the processor. After receiving the signal, the processor analyzes and processes it and sends the signal to the limiting circuit or the amplifying circuit. The limiting circuit includes a fixed limiting circuit and a dynamic limiting circuit. The processor includes a single chip microcomputer, and the single chip microcomputer is respectively connected to the dynamic limiting circuit and the amplifying circuit; The dynamic limiting circuit includes a field effect transistor, the gate of the field effect transistor is connected to the single chip microcomputer in the processor, and the single chip microcomputer sends a signal to the field effect transistor to control the switch of the field effect transistor; The amplifier circuit includes a digital-to-analog converter circuit, which includes a digital-to-analog converter. The digital-to-analog converter is connected to the single-chip microcomputer. The digital-to-analog converter receives a signal sent by the single-chip microcomputer and outputs a voltage to the amplifier circuit after conversion.

2. The switching limiter low noise amplifier according to claim 1, characterized in that: The fixed amplitude limiting circuit comprises a common diode and a Schottky diode, and the common diode and the Schottky diode are connected in parallel.

3. The switching limiter low noise amplifier according to claim 1, characterized in that: It also includes an attenuation circuit, wherein the input end of the attenuation circuit receives a microwave signal, and after attenuation processing by the attenuation circuit, the attenuation circuit sends the processed microwave signal to a limiting circuit connected thereto.

4. The switching limiter low noise amplifier according to claim 1, characterized in that: It also includes a filter circuit. After receiving the signal sent by the limiting circuit connected to it, the filter circuit processes the signal, and after the processing is completed, sends the signal to the amplifier circuit connected to it.

5. The switching limiter low noise amplifier according to claim 4, characterized in that: The filter circuit is an LC filter circuit, and the LC filter circuit includes an inductor and a capacitor, and the inductor and the capacitor are connected in parallel.

6. The switching limiter low noise amplifier according to claim 1, characterized in that: The dynamic amplitude limiting circuit further includes a diode connected to the drain of the field effect transistor.

7. The switching limiter low noise amplifier according to claim 1, characterized in that: It also includes a power supply module, which is connected to the processor, the amplifying circuit, and the noise reduction circuit respectively.

8. The switching limiter low noise amplifier according to claim 1, characterized in that: The model of the digital-to-analog converter is DAC8830IDR.

9. The switching limiter low noise amplifier according to claim 1, characterized in that: The model of the single chip microcomputer is STM32F103C8T6.

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