Automatic level control system

By introducing feedback loops of directional coupling unit, A/D conversion unit, analog operation unit and gain control unit into the automatic level control system, the problem of large dynamic changes of amplifier in the automatic level control system is solved, and automatic level control and stabilization of amplifier are realized.

CN224249668UActive Publication Date: 2026-05-15SICHUAN BOPU MICROWAVE TECH CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
SICHUAN BOPU MICROWAVE TECH CO LTD
Filing Date
2025-05-19
Publication Date
2026-05-15

AI Technical Summary

Technical Problem

Amplifiers in automatic level control systems exhibit significant dynamic changes and are easily affected by environmental factors, leading to rapid and frequent level switching and drastic dynamic changes.

Method used

A feedback loop is formed by a directional coupling unit, an A/D conversion unit, an analog computing unit, and a gain control unit. The detection voltage is stabilized by the mature detection device and equivalent LC matching network of the A/D conversion unit. The external control part of the analog computing unit performs feedback calculations, and the gain control unit adjusts the amplifier gain to achieve automatic level control.

Benefits of technology

It achieves automatic level control of the amplifier, stabilizes level changes, avoids excessive dynamic changes, and adapts to various signal modes and scenarios.

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Abstract

The utility model discloses an automatic level control system, which relates to the technical field of radio frequency communication and comprises a feedback loop formed by sequentially connecting a directional coupling unit, an A / D (analog / digital) conversion unit, an analog operation unit, a gain control unit and an amplifier. The analog operation unit is also used as an external control level input end, the gain control unit is also used as a signal input end of the automatic level control system, and the directional coupling unit is also used as a signal output end. The utility model provides a simple and convenient design mode, the circuit is simple, the cost is low, the reliability is high, the application range is wide, and the practicability is strong.
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Description

Technical Field

[0001] This application relates to the field of radio frequency circuit technology, and in particular to an automatic level control system. Background Technology

[0002] Amplifiers are the most basic and widely used microwave circuit functional units in radio frequency and microwave systems. For an amplifier, its amplification capability is very limited within a typical dynamic range and is easily affected by changes in the environment, the device itself, and changes in the operating point caused by the environment, which can lead to considerable dynamic changes in the amplifier.

[0003] Especially in automatic level control systems, the levels switch rapidly and frequently, resulting in more drastic dynamic changes in the amplifier. Utility Model Content

[0004] To address the aforementioned shortcomings in the existing technology, this utility model provides a level automatic control system that solves the problem of large dynamic changes in amplifiers within the level automatic control system.

[0005] To achieve the above-mentioned utility model objectives, the technical solution adopted by this utility model is as follows: a level automatic control system, comprising: a feedback loop formed by sequentially connecting a directional coupling unit, an A / D conversion unit, an analog operation unit, a gain control unit, and an amplifier;

[0006] The analog computing unit also serves as an external control level input terminal, the gain control unit also serves as a signal input terminal of the level automatic control system, and the directional coupling unit also serves as a signal output terminal.

[0007] Furthermore, the A / D conversion unit includes a detector whose output voltage is inversely proportional to the power and an equivalent LC matching network.

[0008] Furthermore: the analog computing unit includes an interconnected preprocessing section and an external control section;

[0009] The preprocessing section is connected to the A / D conversion unit, and the external control section is connected to the gain control unit.

[0010] Furthermore, the preprocessing section includes an operational amplifier N5 (model AD826ARZ). The output 1 cathode of operational amplifier N5 is connected to one end of resistor R16 and one end of resistor R19, respectively. The other end of resistor R16 is connected to the external control section. The other end of resistor R19 is connected to the invert pin of operational amplifier N5 and one end of resistor R23, respectively. The other end of resistor R23 serves as the positive voltage input terminal. The non-in pin of operational amplifier N5 is connected to one end of resistor R25 and grounding resistor R26, respectively. The other end of resistor R25 is connected to a 5V voltage. The VCC- pin of operational amplifier N5 is connected to grounding capacitor C22 and resistor R2... One end of resistor R8 is connected, and the other end of resistor R28 is connected to a -0.6V voltage. The VCC+ pin of operational amplifier N5 is connected to ground capacitor C21 and 5V voltage respectively. The Output2 pin of operational amplifier N5 is connected to one end of resistor R17 and one end of resistor R21 respectively. The other end of resistor R17 is connected to the A / D conversion unit. The other end of resistor R21 is connected to the Invert pin of operational amplifier N5 and one end of resistor R24 ​​respectively. The other end of resistor R24 ​​serves as the inverted voltage input terminal. The Non-in2 pin of operational amplifier N5 is connected to one end of resistor R29 and ground resistor R30 respectively. The other end of resistor R29 is connected to a 5V voltage.

[0011] Furthermore: The external control section includes an operational amplifier N18 of model AD826ARZ. The VCC+ pin of operational amplifier N18 is connected to ground capacitor C76 and one end of resistor R121, respectively. The other end of resistor R121 is connected to 5V. The Invert pin of operational amplifier N18 is connected to one end of ground resistor R98 and resistor R97, respectively. The other end of resistor R97 is connected to the Output2 pin of operational amplifier N18 and one end of resistor R94, respectively. The other end of resistor R94 is connected to the NO pin of switch controller U2 of model DG4599, one end of resistor R92, and ground resistor R122, respectively. The other end of resistor R92 is connected to one end of resistor R93 and the Output1 pin of operational amplifier N18, respectively. The other end of resistor R93 is connected to operational amplifier N18... The Invert pin of the operational amplifier is connected to one end of resistor R95, and the other end of resistor R95 is connected to the other end of resistor R16. The VCC- pin of operational amplifier N18 is connected to one end of ground capacitor C77 and resistor R101, and the other end of resistor R101 is connected to -0.6V voltage. The Non-in pin of operational amplifier N18 is connected to one end of ground resistor R100 and resistor R96, and the other end of resistor R96 is connected to ground capacitor C78, ​​ground capacitor C79 and the IN- pin of operational amplifier N17 (model LM7321MF). The V+ pin of operational amplifier N17 is connected to ground capacitor C75. The IN+ pin of operational amplifier N17 is connected to one end of ground capacitor C80, ground resistor R103 and resistor R99, and the other end of resistor R99 is used as an external control level input terminal.

[0012] The NC pin of switch controller U2 is connected to one end of resistor R87 and one end of resistor R88. The other end of resistor R87 is connected to a 5V voltage, and the other end of resistor R88 is connected to grounding resistor R89. The COM pin of switch controller U2 is connected to one end of grounding capacitors C70 and C72, and resistor R84. The other end of resistor R84 is connected to one end of grounding capacitors C88 and C87, and resistor R137. The other end of resistor R137 is connected to variable gain amplifier V2092. The V+ pin of switch controller U2 is connected to grounding capacitor C74. The IN pin of the controller U2 is connected to one end of the grounding capacitor C68, grounding capacitor C69, grounding resistor R91, and resistor R90. The other end of resistor R90 is connected to the 2Y pin of inverter N16 (model SN74LVC2G04DCKR). The VCC pin of inverter N16 is connected to one end of the grounding capacitor C71 and resistor R112. The other end of resistor R112 is connected to 5V voltage. The 2A pin of inverter N16 is connected to one end of the grounding capacitor C73, grounding resistor R85, and resistor R86. The other end of resistor R86 is connected to the gain control unit.

[0013] Furthermore, resistors R94, R97, and R98 together constitute the amplification factor setting unit.

[0014] Furthermore: The operational amplifier N18, together with resistors R93, R95, R96 and R100, constitutes a subtraction operation unit.

[0015] Furthermore: the gain control unit uses a variable gain amplifier. 。

[0016] The beneficial effects of this utility model are as follows:

[0017] 1. The A / D conversion unit uses mature detection devices, and the output voltage is inversely proportional to the power to adapt to various signal modes and application scenarios. The detection voltage is stabilized through an equivalent LC matching network.

[0018] 2. The external control section of the analog operation unit uses an operational amplifier N18 and a subtraction operation unit composed of resistors R93, R95, R96, and R100 to stabilize the external control voltage and perform feedback calculation with the detected voltage after inversion processing. The switch controller U2 adjusts the switching of the fixed output voltage and the feedback loop to realize the automatic level control function to turn on and off.

[0019] 3. By feeding back changes in output power and external control level through the gain control unit, the amplifier gain is adjusted and the level is automatically controlled, thus avoiding problems such as large dynamic changes in amplification. Attached Figure Description

[0020] Figure 1 This is a diagram of the level-based automatic control system framework.

[0021] Figure 2 Schematic diagram of the preprocessing section for the analog computing unit;

[0022] Figure 3 This is the control principle diagram of the analog computing unit. Detailed Implementation

[0023] The specific embodiments of this utility model are described below to enable those skilled in the art to understand this utility model. However, it should be understood that this utility model is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of this utility model as defined and determined by the appended claims, these changes are obvious. All creations utilizing the concept of this utility model are protected.

[0024] like Figure 1 As shown, in one embodiment of this utility model, a level automatic control system is provided, including: a directional coupling unit, an A / D conversion unit, an analog operation unit, a gain control unit, and an amplifier connected in sequence to form a feedback loop;

[0025] The analog computing unit also serves as an external control level input terminal, the gain control unit also serves as a signal input terminal of the level automatic control system, and the directional coupling unit also serves as a signal output terminal.

[0026] In this system, the amplifier output signal is proportionally distributed through a directional coupling unit, enabling the A / D conversion unit system to accurately read the current output power status of the amplifier.

[0027] The analog computing unit includes interconnected preprocessing and external control sections;

[0028] The preprocessing section is connected to the A / D conversion unit, and the external control section is connected to the gain control unit.

[0029] like Figure 2As shown, the preprocessing section includes an operational amplifier N5 (model AD826ARZ). The cathode of operational amplifier N5's Output1 is connected to one end of resistor R16 and one end of resistor R19, respectively. The other end of resistor R16 is connected to the external control section. The other end of resistor R19 is connected to the Invert pin of operational amplifier N5 and one end of resistor R23, respectively. The other end of resistor R23 serves as the positive voltage input terminal. The Non-in pin of operational amplifier N5 is connected to one end of resistor R25 and ground resistor R26, respectively. The other end of resistor R25 is connected to a 5V voltage. The VCC- pin of operational amplifier N5 is connected to ground capacitor C22 and resistor R28, respectively. One end of the resistor R28 is connected to the ground capacitor C21 and the 5V voltage. The Output2 pin of the operational amplifier N5 is connected to one end of the resistor R17 and one end of the resistor R21. The other end of the resistor R17 is connected to the A / D conversion unit. The other end of the resistor R21 is connected to the Invert pin of the operational amplifier N5 and one end of the resistor R24. The other end of the resistor R24 ​​serves as the inverting voltage input terminal. The Non-in2 pin of the operational amplifier N5 is connected to one end of the resistor R29 and the ground resistor R30. The other end of the resistor R29 is connected to the 5V voltage.

[0030] During the calculation process, the voltage is amplified, filtered, and limited by R19, R24, R25, and R26, and then converted into a detector voltage that increases with power. This voltage is then output to the external control section of the analog computing unit via R16.

[0031] like Figure 3As shown, the external control section includes an operational amplifier N18 of model AD826ARZ. The VCC+ pin of operational amplifier N18 is connected to ground capacitor C76 and one end of resistor R121, respectively. The other end of resistor R121 is connected to a 5V voltage. The Invert pin of operational amplifier N18 is connected to ground resistor R98 and one end of resistor R97, respectively. The other end of resistor R97 is connected to the Output2 pin of operational amplifier N18 and one end of resistor R94, respectively. The other end of resistor R94 is connected to the NO pin of switch controller U2 of model DG4599, one end of resistor R92, and ground resistor R122, respectively. The other end of resistor R92 is connected to one end of resistor R93 and the Output1 pin of operational amplifier N18, respectively. The other end of resistor R93 is connected to the... The Invert pin is connected to one end of resistor R95, and the other end of resistor R95 is connected to the other end of resistor R16. The VCC- pin of operational amplifier N18 is connected to one end of ground capacitor C77 and resistor R101. The other end of resistor R101 is connected to -0.6V. The Non-in pin of operational amplifier N18 is connected to one end of ground resistor R100 and resistor R96. The other end of resistor R96 is connected to ground capacitors C78 and C79 and the IN- pin of operational amplifier N17 (model LM7321MF). The V+ pin of operational amplifier N17 is connected to ground capacitor C75. The IN+ pin of operational amplifier N17 is connected to one end of ground capacitor C80, ground resistor R103 and resistor R99. The other end of resistor R99 serves as an external control level input.

[0032] The NC pin of switch controller U2 is connected to one end of resistor R87 and one end of resistor R88. The other end of resistor R87 is connected to a 5V voltage, and the other end of resistor R88 is connected to grounding resistor R89. The COM pin of switch controller U2 is connected to one end of grounding capacitors C70 and C72, and resistor R84. The other end of resistor R84 is connected to one end of grounding capacitors C88 and C87, and resistor R137. The other end of resistor R137 is connected to variable gain amplifier V2092. The V+ pin of switch controller U2 is connected to grounding capacitor C74. The IN pin of the controller U2 is connected to one end of the grounding capacitor C68, grounding capacitor C69, grounding resistor R91, and resistor R90. The other end of resistor R90 is connected to the 2Y pin of inverter N16 (model SN74LVC2G04DCKR). The VCC pin of inverter N16 is connected to one end of the grounding capacitor C71 and resistor R112. The other end of resistor R112 is connected to 5V voltage. The 2A pin of inverter N16 is connected to one end of the grounding capacitor C73, grounding resistor R85, and resistor R86. The other end of resistor R86 is connected to the gain control unit.

[0033] In the external control section of the analog computing unit, a subtraction application unit composed of operational amplifier N18 and resistors R93, R95, R96, and R100 performs feedback calculations on the external control voltage, which has been isolated and stabilized by operational amplifier N17, and the detector voltage, which has undergone inversion processing. The result is output to the switch controller U2 through resistor R92. The externally provided automatic level control enable switch adjusts the fixed output voltage and the switching of the feedback loop through the U2 switch controller to realize the automatic level control function's on / off state.

[0034] Specifically, resistors R94, R97, and R98 together constitute the amplification factor setting unit, thereby adjusting the amplification factor of operational amplifier N17 for the detector voltage to meet different actual amplifier usage requirements and customize response accuracy and response speed.

[0035] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A level-based automatic control system, characterized in that, include: The feedback loop is formed by connecting the directional coupling unit, A / D conversion unit, analog computing unit, gain control unit and amplifier in sequence; The analog computing unit also serves as an external control level input terminal, the gain control unit also serves as a signal input terminal of the level automatic control system, and the directional coupling unit also serves as a signal output terminal.

2. The level-based automatic control system according to claim 1, characterized in that, The A / D conversion unit includes a detector whose output voltage is inversely proportional to the power and an equivalent LC matching network.

3. The level-based automatic control system according to claim 1, characterized in that, The analog computing unit includes interconnected preprocessing and external control sections; The preprocessing section is connected to the A / D conversion unit, and the external control section is connected to the gain control unit.

4. The level-based automatic control system according to claim 3, characterized in that, The preprocessing section includes an operational amplifier N5 (model AD826ARZ). The output 1 cathode of operational amplifier N5 is connected to one end of resistor R16 and one end of resistor R19, respectively. The other end of resistor R16 is connected to the external control section. The other end of resistor R19 is connected to the invert pin of operational amplifier N5 and one end of resistor R23, with the other end of resistor R23 serving as the positive voltage input. The non-in pin of operational amplifier N5 is connected to one end of resistor R25 and ground resistor R26, with the other end of resistor R25 connected to a 5V voltage. The VCC- pin of operational amplifier N5 is connected to the ground capacitor C22 and resistor R28. One end of the resistor R28 is connected to the -0.6V voltage. The VCC+ pin of the operational amplifier N5 is connected to the ground capacitor C21 and the 5V voltage. The Output2 pin of the operational amplifier N5 is connected to one end of the resistor R17 and one end of the resistor R21. The other end of the resistor R17 is connected to the A / D conversion unit. The other end of the resistor R21 is connected to the Invert pin of the operational amplifier N5 and one end of the resistor R24. The other end of the resistor R24 ​​serves as the inverting voltage input terminal. The Non-in2 pin of the operational amplifier N5 is connected to one end of the resistor R29 and the ground resistor R30. The other end of the resistor R29 is connected to the 5V voltage.

5. The automatic level control system according to claim 4, characterized in that, The external control section includes an operational amplifier N18 (model AD826ARZ). The VCC+ pin of operational amplifier N18 is connected to ground capacitor C76 and one end of resistor R121, respectively. The other end of resistor R121 is connected to a 5V voltage. The Invert pin of operational amplifier N18 is connected to ground resistor R98 and one end of resistor R97, respectively. The other end of resistor R97 is connected to the Output2 pin of operational amplifier N18 and one end of resistor R94, respectively. The other end of resistor R94 is connected to the NO pin of switch controller U2 (model DG4599), one end of resistor R92, and ground resistor R122, respectively. The other end of resistor R92 is connected to one end of resistor R93 and the Output1 pin of operational amplifier N18, respectively. The other end of resistor R93 is connected to the Invert pin of operational amplifier N18, respectively. The vert pin is connected to one end of resistor R95, and the other end of resistor R95 is connected to the other end of resistor R16. The VCC- pin of operational amplifier N18 is connected to one end of ground capacitor C77 and resistor R101. The other end of resistor R101 is connected to -0.6V voltage. The Non-in pin of operational amplifier N18 is connected to one end of ground resistor R100 and resistor R96. The other end of resistor R96 is connected to ground capacitor C78, ​​ground capacitor C79 and the IN- pin of operational amplifier N17 (model LM7321MF). The V+ pin of operational amplifier N17 is connected to ground capacitor C75. The IN+ pin of operational amplifier N17 is connected to one end of ground capacitor C80, ground resistor R103 and resistor R99. The other end of resistor R99 is used as an external control level input terminal. The NC pin of switch controller U2 is connected to one end of resistor R87 and one end of resistor R88. The other end of resistor R87 is connected to a 5V voltage, and the other end of resistor R88 is connected to grounding resistor R89. The COM pin of switch controller U2 is connected to one end of grounding capacitors C70 and C72, and resistor R84. The other end of resistor R84 is connected to one end of grounding capacitors C88 and C87, and resistor R137. The other end of resistor R137 is connected to variable gain amplifier V2092. The V+ pin of switch controller U2 is connected to grounding capacitor C74. The IN pin of the controller U2 is connected to one end of the grounding capacitor C68, grounding capacitor C69, grounding resistor R91, and resistor R90. The other end of resistor R90 is connected to the 2Y pin of inverter N16 (model SN74LVC2G04DCKR). The VCC pin of inverter N16 is connected to one end of the grounding capacitor C71 and resistor R112. The other end of resistor R112 is connected to 5V voltage. The 2A pin of inverter N16 is connected to one end of the grounding capacitor C73, grounding resistor R85, and resistor R86. The other end of resistor R86 is connected to the gain control unit.

6. The level-based automatic control system according to claim 5, characterized in that, Resistors R94, R97, and R98 together constitute the amplification factor setting unit.

7. The automatic level control system according to claim 5, characterized in that, Operational amplifier N18, together with resistors R93, R95, R96 and R100, constitutes a subtraction unit.

8. The level-based automatic control system according to claim 1, characterized in that, The gain control unit uses a variable gain amplifier V2092.