Power Amplifier Output Network for Third-Harmonic Phase Control
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Solution Overview
Problem
Existing power amplifier circuits face difficulties in appropriately adjusting the phase of the third harmonic wave reflection coefficient, which affects the efficiency of the amplifier operation.
Innovation Solution
A power amplifier circuit design that includes an amplifier, a matching circuit, and resonant circuits to adjust the phase of the third harmonic wave by using a resonant circuit that resonates at frequencies greater than or equal to the fourth harmonic wave, allowing for impedance conversion and phase adjustment of the third harmonic wave without terminating it, thereby enhancing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a variable line tuner for third harmonic wave is connected to a harmonic wave reflection filter, then the phase of reflection coefficient of harmonic wave can be adjusted, but it is difficult to appropriately adjust the phase of reflection coefficient of third harmonic wave
Solution Approach 1:
The patent changes the resonant frequency parameter of the resonant circuit from traditional values (below third harmonic) to a new range (greater than or equal to fourth harmonic frequency). This parameter change enables the resonant circuit to provide appropriate reactance at the third harmonic frequency without directly resonating at it, thereby achieving proper phase adjustment of the reflection coefficient that was not possible with conventional designs.
2Loss of energy
If a resonant circuit resonating at third harmonic frequency is used, then the third harmonic wave can be terminated, but the phase of reflection coefficient cannot be appropriately adjusted
Solution Approach 1:
Instead of resonating at the third harmonic frequency to terminate the wave, the patent inverts the approach by resonating at frequencies greater than or equal to the fourth harmonic. This inverted frequency selection allows the circuit to provide the desired reactive impedance at the third harmonic frequency without direct resonance, thereby simultaneously achieving both termination and phase adjustment capabilities.
3Device complexity
If conventional harmonic wave filters are used, then the circuit structure is simple, but the amplifier efficiency cannot be optimized due to improper phase adjustment
Solution Approach 1:
The patent modifies the resonant frequency parameter of the existing resonant circuit structure to be greater than or equal to the fourth harmonic frequency. This simple parameter change maintains the circuit's structural simplicity while fundamentally improving its ability to adjust the phase of the reflection coefficient, thereby optimizing amplifier efficiency without adding complex circuitry.
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
The circuit enables precise adjustment of the third harmonic wave phase, improving amplifier efficiency and reducing losses, while using smaller components and maintaining optimal output power and current levels.
Implementation Method 1
a resonant circuit provided between ground and a signal path that connects the output port of the amplifier and the input of the matching circuit, the resonant circuit resonating at a resonant frequency that is greater than or equal to a frequency of a fourth harmonic wave of the amplified signal
Data Source
AI summary
A power amplifier circuit includes an amplifier that amplifies an input signal RFin, a matching circuit that provides impedance matching between an output port of the amplifier and an output terminal, an input of the matching circuit being connected to the output port of the amplifier, an output of the matching circuit being connected to the output terminal, and a resonant circuit provided between ground and a signal path that connects the output port of the amplifier and the input of the matching circuit, the resonant circuit resonating at a resonant frequency greater than or equal to the frequency of a fourth harmonic wave of an amplified signal obtained by amplifying the input signal.