High-Frequency Power Amplifier Matching Circuit for Flat Output Power

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

High-frequency power amplifiers struggle to maintain flat output power characteristics over a wide band while amplifying high-frequency signals with high-speed modulation, as existing solutions fail to effectively control voltage variable capacitance diodes for efficient amplification.

Innovation Solution

A high-frequency power amplifier configuration that includes an input terminal, input matching circuit, amplifying element, output matching circuit, coupling circuit, and detection circuit, where either the input or output matching circuit has an active element that adjusts impedance based on control voltage to maintain flat output power across the operating band.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a voltage variable capacitance diode is controlled by driving a DC amplifier, then output power characteristics can be adjusted, but the amplifier cannot amplify high frequency signals following high speed modulation

Engineering Contradiction:
Improvemodulation speedVSAvoidamplification capability
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent replaces the mechanical/electronic DC amplifier control system with a direct voltage control mechanism. The control voltage is applied directly to the gate terminal of the active element in the matching circuit, eliminating the need for a DC amplifier and enabling high-speed modulation response while maintaining amplification capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If either the input or output matching circuit has an active element controlled by voltage, then flat output power characteristics over wide band are achieved, but device complexity increases

Engineering Contradiction:
Improveoutput power flatnessVSAvoidcircuit complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent makes the matching circuit multi-functional by incorporating an active element that can be controlled by voltage. This single active element performs both impedance matching and output power control functions, achieving flat output power characteristics over a wide band without significantly increasing overall device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If voltage variable capacitance diode control is implemented, then output power can be adjusted, but power consumption increases

Engineering Contradiction:
Improveoutput power controlVSAvoidpower consumption
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent implements a self-service control mechanism where the control voltage directly modulates the active element in the matching circuit. This eliminates the need for additional control amplifiers and power consumption associated with complex control circuits, while still enabling output power adjustment and flatness control.

Inventive Principle:
Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution enables the high-frequency power amplifier to achieve flat output power characteristics over an operating band while amplifying high-frequency signals with high-speed modulation, reducing power consumption and maintaining efficient gain across varying input power levels.

Implementation Method 1

controls a voltage variable capacitance diode

Methodology Applied
Scientific EffectVoltage variable capacitance: Capacitance

Data Source

PatentEP3905533B1High-frequency power amplifier
Publication Date: 2023.03.29 MITSUBISHI ELECTRIC CORP
  • EP3905533B1 patent drawingFigure 1~2
  • EP3905533B1 patent drawingFigure 3~5
  • EP3905533B1 patent drawingFigure 6

AI summary

A high-frequency power amplifier (100, 100a) is configured in such a way as to include an input matching circuit (110, 110a), an amplifying element (120), an output matching circuit (130, 130a), a coupling circuit (140), a detection circuit (150), and an output terminal (199), and in such a way that either the input matching circuit (110) or the output matching circuit (130a) has an active element (160, 160a), the detection circuit (150) receives a signal outputted by the coupling circuit (140) and outputs a control voltage into which the detection circuit (150) converts the signal to the active element (160, 160a), and the active element (160, 160a) changes the impedance of the active element (160, 160a) in accordance with the control voltage outputted by the detection circuit (150), thereby changing the power of a signal outputted by either the input matching circuit (110) having the active element (160, 160a) or the output matching circuit having the active element (130a), to change the power of a signal which the coupling circuit (140) outputs to the output terminal (199) .