RF Transceiver Pre-Distortion Using Dual-Tone Attenuation Calibration
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Solution Overview
Problem
Power amplifiers in communication devices suffer from nonlinear distortion due to non-linear gain characteristics, leading to signal distortion and misjudgment in power spectral density measurements.
Innovation Solution
A transceiver system with a signal generator and controller circuit, pre-distortion module, and attenuator circuit that generates and adjusts attenuation ranges based on dual-tone and single-tone signals to compensate for power amplifier distortion by executing pre-distortion processes at the baseband end, using digital pre-distortion algorithms and hardware components to improve signal linearity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a power amplifier is used to amplify signals in communication devices, then signal transmission capability is improved, but nonlinear distortion occurs due to non-linear gain characteristics
Solution Approach 1:
The patent applies pre-distortion technology that performs preliminary compensation on the input signal before it enters the power amplifier. By pre-modifying the signal characteristics in the opposite direction of the expected distortion, the system counteracts the nonlinear effects of the power amplifier, thereby reducing output distortion while maintaining signal amplification capability.
2Ease of operation
If traditional single-tone signal testing is used for power amplifier characterization, then measurement simplicity is maintained, but measurement accuracy is insufficient due to inability to capture full nonlinear characteristics
Solution Approach 1:
The patent segments the power amplifier's operating range into multiple discrete power levels. By conducting separate measurements at each power level using single-tone signals and then synthesizing the results, the system achieves comprehensive characterization of nonlinear characteristics while maintaining the simplicity of single-tone testing methods.
Solution Approach 2:
The patent changes the power level parameter of the test signal across multiple measurement stages. By systematically varying the input power and measuring output characteristics at each level, the system captures the full nonlinear behavior of the power amplifier without requiring complex multi-tone test signals.
Data Source
AI summary
A transceiver system includes a signal generator and controller circuit, a first signal converter circuit, an attenuator circuit, and a second signal converter circuit. Signal generator and controller circuit generates a transmitting baseband signal. First signal converter circuit generates a transmitting radio frequency signal according to transmitting baseband signal. Attenuator circuit generates an attenuated radio frequency signal according to transmitting radio frequency signal. Second signal converter circuit generates an attenuation range baseband reference signal according to attenuated radio frequency signal. Signal generator and controller circuit determines a first attenuation range for attenuator circuit according to attenuation range baseband reference signal when transmitting baseband signal is a dual-tone signal, and determines a second attenuation range from first attenuation range for attenuator circuit according to attenuation range baseband reference signal when transmitting baseband signal is a single-tone signal, and second attenuation range is for a pre-distortion process.