Power Amplifier Circuit With Second-Harmonic Distortion Compensation
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Solution Overview
Problem
Power amplifier circuits in mobile communication devices face increased insertion loss due to multiple frequency bands, leading to insufficient power of added harmonic waves for compensating intermodulation distortion, especially with the rise in output power demands for 4G and 5G systems.
Innovation Solution
A power amplifier circuit design that includes a power divider, distortion compensation circuit, and power combiner to generate and amplify a second-harmonic wave, which is combined with the fundamental wave to cancel out intermodulation distortion, using a phase adjustment circuit to ensure effective compensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the number of filter circuits is increased to support multiple frequency bands, then adaptability is improved, but insertion loss increases
Solution Approach 1:
The signal path is divided into a fundamental wave path and a second-harmonic wave path, with separate processing for each frequency component. This segmentation allows independent optimization of each path to reduce overall insertion loss while supporting multiple frequency bands.
Solution Approach 2:
The patent changes the frequency parameter by generating and processing second-harmonic waves at a different frequency from the fundamental wave. This parameter change enables the use of dedicated filter circuits for each harmonic, reducing cumulative insertion loss across multiple frequency bands.
2Power
If output power of transmit signals is increased to compensate for insertion loss, then power is improved, but intermodulation distortion increases
Solution Approach 1:
The patent applies preliminary anti-action by generating second-harmonic waves with specific amplitude and phase characteristics before they combine with the fundamental wave. This pre-configured anti-action reduces intermodulation distortion components that would otherwise be generated when high-power signals pass through the power amplifier.
Solution Approach 2:
The patent converts the harmful second-harmonic distortion components into a beneficial element by deliberately generating and controlling second-harmonic waves to cancel out intermodulation distortion. The previously harmful harmonic components become useful for distortion compensation.
3Object-generated harmful factors
If a second-harmonic wave is added for distortion compensation, then intermodulation distortion is reduced, but power of the second-harmonic wave is insufficient when output power is increased
Solution Approach 1:
The patent applies preliminary action by generating and amplifying the second-harmonic wave before it combines with the fundamental wave in the power amplifier. The second-harmonic wave is pre-amplified to ensure it has sufficient power to effectively cancel intermodulation distortion even when the overall output power is increased.
Solution Approach 2:
The patent introduces a dedicated second-harmonic wave generation circuit and amplification circuit as intermediary components. These intermediary circuits specifically handle the second-harmonic wave generation and amplification, ensuring sufficient power is available for distortion compensation without limiting the overall output power capability.
4Adaptability or versatility
If multiple filter circuits are added to support new communication standards, then adaptability is improved, but device complexity increases
Solution Approach 1:
The patent implements multi-functionality by designing filter circuits that can handle both fundamental waves and second-harmonic waves within a unified architecture. The same filter circuit structure serves multiple purposes: filtering fundamental frequencies and filtering second-harmonic frequencies, thereby supporting multiple communication standards without proportionally increasing complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enhances output power while reducing intermodulation distortion, improving linearity and output power efficiency compared to previous designs by ensuring a high-power second-harmonic wave is effectively added to the amplifier stage.
Implementation Method 1
a generation circuit configured to generate the second-harmonic wave of the input signal
Implementation Method 2
a filter circuit configured to attenuate the fundamental wave and pass the second-harmonic wave
Implementation Method 3
a phase adjustment circuit configured to adjust the phase of the second-harmonic wave
Data Source
AI summary
Provided is a power amplifier circuit that can increase output power and also reduce the effect of intermodulation distortion. The power amplifier circuit includes a power divider, a distortion compensation circuit provided on the secondary path, a power combiner, and a first amplifier configured. The distortion compensation circuit includes a generation circuit configured to generate the second-harmonic wave of the input signal, a filter circuit configured to attenuate the fundamental wave and pass the second-harmonic wave, and a phase adjustment circuit configured to adjust the phase of the second-harmonic wave.