Power Amplifier Circuit With Voltage Limiting for RF Gain Stability
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Solution Overview
Problem
The quality of radio-frequency output signals from power amplifier circuits is degraded due to variations in power supply voltage, leading to gain shifts and inefficiencies.
Innovation Solution
A power amplifier circuit with a voltage limiter circuit and an RC series circuit that restricts the power supply voltage to a predetermined range, connected in parallel with the voltage limiter circuit, to stabilize the power supply voltage and reduce gain deviations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the power supply voltage is varied to improve power amplification efficiency, then power amplification efficiency is improved, but the gain of the power amplifier circuit shifts and the quality of the radio-frequency signal is degraded
Solution Approach 1:
The patent applies parameter changes by introducing a voltage limiter circuit that dynamically adjusts and constrains the power supply voltage to a predetermined range. This circuit monitors the power supply voltage and limits it when it exceeds the specified range, thereby preventing gain shifts while still allowing efficiency improvements through controlled voltage variation. The voltage limiter circuit transforms the uncontrolled voltage variation into a controlled parameter change that maintains signal quality.
2Reliability
If a voltage limiter circuit is added to restrict power supply voltage, then the quality of radio-frequency output signals is improved, but the device complexity increases
Solution Approach 1:
The voltage limiter circuit serves as an intermediary component between the power supply and the power amplifier. It mediates the power supply voltage by filtering and limiting it to appropriate levels before reaching the amplifier stages. This intermediary approach protects the sensitive amplifier circuits from voltage fluctuations while maintaining a relatively simple overall system architecture, as the limiter can be implemented with basic electronic components.
Data Source
AI summary
A power amplifier circuit includes a power amplifier and an external power terminal that receives a power supply voltage from a power supply circuit. The power amplifier includes two amplifying elements and, a limiter, and an RC circuit. The amplifying elements respectively include first and second input terminals, first and second output terminals, and first and second power terminals. The limiter restricts the power supply voltage to a predetermined range and outputs the restricted power supply voltage. The RC circuit is connected in parallel with the limiter. The first input terminal is connected to an external input terminal. The first output terminal is connected to the second input terminal. The second output terminal is connected to an external output terminal. The first power terminal is connected to the external power terminal via the limiter. The second power terminal is connected to the external power terminal.