Power Amplifier Control Circuit for TX/RX Supply Swing Suppression
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Solution Overview
Problem
In transmit/receive switching systems like TDD, the power amplifier experiences non-linear operation due to power supply voltage swings during mode switching, leading to signal corruption.
Innovation Solution
A circuitry with a load circuit and a first switch is used to absorb the power supply voltage swing, switching on ahead of the power amplifier activation, thereby reducing the voltage swing's impact during transmission initiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the power amplifier is turned on when transmission is initiated, then the system responds quickly to transmission start, but the power supply voltage swing causes non-linear operation and signal distortion
Solution Approach 1:
The patent applies preliminary action by turning on the power amplifier during the guard period before the actual transmission starts. This advance activation allows the PA to be fully operational when the transmission signal begins, preventing voltage swings during critical signal amplification while maintaining quick response through pre-positioning the PA in an ready state during the guard period
2Reliability
If the power amplifier is turned on in advance during guard period, then linear operation is maintained, but reception may be corrupted due to premature PA actuation
Solution Approach 1:
The patent applies dynamics by implementing different PA activation strategies for transmission and reception directions. During uplink transmission, the PA is activated during the guard period before downlink transmission. During downlink reception, the PA remains off until the actual reception starts, dynamically adapting the activation timing based on the communication direction to prevent reception corruption while maintaining transmission quality
3Device complexity
If fast TX/RX switching is implemented, then system simplicity is improved, but power supply voltage swing causes non-linear PA operation
Solution Approach 1:
The patent applies preliminary action by utilizing the guard period in TDD systems to pre-activate the power amplifier before transmission begins. This timing strategy allows the PA to be fully operational during the actual transmission window, eliminating voltage swing effects during signal amplification while maintaining the simplicity of fast TX/RX switching through proper temporal coordination
Data Source
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Figure 6A
AI summary
According to embodiments of the present disclosure, circuitry (400, 600) and method (800) are provided for controlling a power amplifier (10) in a transmit/receive switching system. The circuitry (400, 600) comprises a load circuit (420, 620) for at least partly reducing a magnitude of a swing of a power supply voltage caused by a variation in load of the transmit/receive switching system that occurs upon initiation of a transmission by the transmit/receive switching system. The circuitry (400, 600) further comprises a first switch (410, 610), coupled in series with the load circuit (420, 620), operable to switch on to couple the power supply voltage to a ground voltage via the load circuit (420, 620). The circuitry (400, 600) further comprises a control circuit (430, 630) configured to switch on the first switch (410, 610) at a first timing, and to switch off the first switch (410, 610) and turn on the power amplifier (10) at a second timing. The first timing is a time interval ahead of the second timing.