Dual-Amplifier Bias Control for Stable Power Mode Switching
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Solution Overview
Problem
Power amplifier circuits experience a gain decrease when switching between high and low power modes, leading to degradation of transmission signals.
Innovation Solution
A power amplifier circuit design that includes two amplifiers and two bias circuits, controlled by a single control circuit, which manages bias currents or voltages to maintain continuous operation of the primary amplifier during mode switching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the power amplifier circuit switches between high power mode and low power mode, then the output power level is adjusted, but the gain temporarily decreases during switching
Solution Approach 1:
The patent applies preliminary action by maintaining a predetermined bias current in the second amplifier even when it is not actively amplifying in low power mode. This preparatory bias current ensures that when switching to high power mode, the amplifier can immediately contribute to signal amplification without gain degradation, thus resolving the contradiction between power level adjustment and gain stability.
Solution Approach 2:
The patent implements continuity of useful action by keeping the second amplifier in a standby state with predetermined bias current flowing through it during low power mode. This continuous readiness ensures seamless transition to high power mode without interruption or gain loss, maintaining continuous useful amplification action across mode transitions.
2Device complexity
If a single amplifier is used for both high and low power modes, then the circuit structure is simplified, but gain degradation occurs during mode switching
Solution Approach 1:
The patent applies segmentation by dividing the amplification function into two separate amplifiers: a first amplifier for low power mode and a second amplifier for high power mode. This segmentation allows each amplifier to be optimized for its specific power level while maintaining gain stability during switching, resolving the contradiction between circuit simplicity and gain reliability.
Solution Approach 2:
The patent implements local quality by providing different bias current conditions to different amplifiers based on the operating mode. The first amplifier receives bias current optimized for low power operation, while the second amplifier receives predetermined bias current for high power readiness, allowing each component to have locally optimized characteristics for its specific function.
3Use of energy by moving object
If bias current is reduced to save power in low power mode, then current consumption decreases, but gain characteristics deteriorate when switching to high power mode
Solution Approach 1:
The patent applies preliminary action by maintaining a predetermined bias current in the second amplifier during low power mode, preparing it in advance for high power operation. This preliminary bias current consumption ensures that when switching to high power mode, the amplifier can immediately provide full gain without degradation, resolving the contradiction between power savings and gain reliability.
Solution Approach 2:
The patent uses the predetermined bias current as an intermediary state that bridges low power mode and high power mode. This intermediary bias current is sufficient to maintain the second amplifier's readiness for high power operation without fully activating it, thus mediating between power consumption reduction and gain characteristic maintenance.
Data Source
AI summary
A power amplifier circuit 10 includes amplifiers 102 and 103, bias circuits 1023 and 1033, and a control circuit 106 that controls the bias circuits 1023 and 1033. When the power amplifier circuit 10 operates in a low power mode, the control circuit 106 controls the bias circuit 1023 and the bias circuit 1033 such that a bias current or voltage is supplied to the amplifier 102 and a bias current or voltage is not supplied to the amplifier 103. When the power amplifier circuit 10 operates in a high power mode in which an output power is higher than an output power in the low power mode, the control circuit 106 controls the bias circuit 1023 and the bias circuit 1033 such that a bias current or voltage is supplied to the amplifier 102 and a bias current or voltage is supplied to the amplifier103.