RF Power Amplifier Control for Intermodulation-Limited Coexistence
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Radio-frequency circuits that support multiband and multimode communication face issues with intermodulation distortion when simultaneously transmitting radio-frequency signals of different frequencies, leading to deterioration in signal quality due to leakage and mixing of signals from power amplifiers.
Innovation Solution
A radio-frequency circuit design that includes two power amplifiers, where at least one amplifier reduces its transmission power when both are simultaneously outputting signals, ensuring the power component of intermodulation distortion is less than or equal to a threshold value, thereby reducing unwanted waves and maintaining signal quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple power amplifiers simultaneously transmit radio-frequency signals of different frequencies, then communication capability is improved, but intermodulation distortion increases causing signal quality deterioration
Solution Approach 1:
The patent dynamically adjusts the transmission power parameter of at least one power amplifier based on the simultaneous transmission state. When multiple amplifiers transmit simultaneously, the system reduces the power of at least one amplifier to suppress intermodulation distortion while maintaining communication functionality. This parameter change resolves the contradiction by adapting power levels to transmission conditions.
2Reliability
If transmission power of power amplifiers is reduced to suppress intermodulation distortion, then signal quality is improved, but transmission efficiency decreases
Solution Approach 1:
The patent implements dynamic power adjustment where the transmission power of power amplifiers is not fixed but varies based on real-time transmission conditions. When simultaneous transmission occurs, power is reduced to maintain signal quality; when transmitting separately, full power is used to maximize efficiency. This dynamic approach resolves the contradiction by adapting power levels to operational context.
Solution Approach 2:
The system periodically monitors the transmission state of multiple power amplifiers and adjusts power levels accordingly. The control mechanism operates in cycles, detecting simultaneous transmission conditions and applying power reduction only when necessary, then restoring full power when conditions allow. This periodic control resolves the contradiction by applying power suppression selectively rather than continuously.
3Productivity
If power amplifiers transmit at full power simultaneously, then transmission efficiency is improved, but unwanted waves such as intermodulation distortion are generated
Solution Approach 1:
The patent employs a feedback control mechanism where the system monitors the transmission state of multiple power amplifiers and adjusts power levels based on this feedback. When simultaneous transmission is detected, the control unit reduces power to suppress unwanted waves; when transmission is sequential, full power is maintained for efficiency. This feedback loop resolves the contradiction by continuously adapting to transmission conditions.
Data Source
AI summary
A radio-frequency circuit includes a first power amplifier that outputs a first transmission signal and a second power amplifier that outputs a second transmission signal having a frequency different from a frequency of the first transmission signal. In a period in which the first transmission signal the second transmission signal are simultaneously outputted, at least one of the first power amplifier or the second power amplifier reduces transmission power of the at least one of the first power amplifier or the second power amplifier to cause a power component of intermodulation distortion superimposed on a transmission signal output from the first power amplifier and the second power amplifier to be less than or equal to a threshold value.