Power Amplifier Harmonic Tuning via FET Parasitic Capacitance
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Solution Overview
Problem
The characteristics of harmonic termination circuits in power amplifier modules deteriorate due to variations in elements, particularly with reduced substrate profiles and increased RF signal frequencies, making it difficult to adjust the circuit characteristics effectively.
Innovation Solution
Incorporating a harmonic termination circuit with at least one field effect transistor (FET) and a control circuit that adjusts the gate voltage of the FET to control the parasitic capacitance, allowing for dynamic adjustment of the resonance frequency to mitigate variations and maintain circuit performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the sizes of elements such as inductors and capacitors are determined in advance in a harmonic termination circuit, then the circuit structure is simple and easy to manufacture, but it becomes difficult to adjust the characteristics of the harmonic termination circuit in accordance with variations of the elements
Solution Approach 1:
The patent applies the dynamics principle by making the harmonic termination circuit adjustable through a control signal. The circuit characteristics can be dynamically changed in response to element variations, allowing the resonance frequency to be tuned after manufacturing. This resolves the contradiction by enabling both easy manufacturing (fixed initial structure) and adaptability (adjustable characteristics through control signals).
Solution Approach 2:
The patent applies parameter changes by modifying the electrical characteristics of the harmonic termination circuit through control signals. By changing parameters such as capacitance or inductance values dynamically, the circuit can compensate for element variations. This allows the circuit to maintain optimal performance despite manufacturing tolerances, resolving the contradiction between fixed manufacturing and adjustable characteristics.
2Speed
If the profile of substrates is reduced and RF signal frequencies are increased, then the power amplifier module achieves higher frequency operation and smaller size, but the characteristics of the harmonic termination circuit deteriorate due to variations from element to element
Solution Approach 1:
The patent applies feedback by using control signals to adjust the harmonic termination circuit characteristics based on detected performance or predetermined compensation requirements. This feedback mechanism allows the circuit to compensate for element variations that become more significant at higher frequencies, maintaining reliability while operating at elevated RF signal frequencies.
Solution Approach 2:
The patent applies dynamics by enabling the harmonic termination circuit to adapt its characteristics dynamically in response to operating conditions and element variations. This dynamic adjustment capability ensures consistent performance across different frequency operations and compensates for the increased sensitivity to element variations that occurs at higher frequencies.
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 solution enables the power amplifier module to maintain consistent harmonic termination circuit characteristics despite elemental variations, ensuring effective signal attenuation across a range of frequencies.
Implementation Method 1
a control circuit that controls a gate voltage of the at least one FET to adjust a capacitance value of a parasitic capacitance of the at least one FET
Implementation Method 2
The control circuit adjusts the capacitance value of the parasitic capacitance of the at least one FET, and thereby a resonance frequency of the harmonic termination circuit is adjusted
Implementation Method 3
a harmonic termination circuit that is disposed subsequent to the amplifier and that attenuates a harmonic component of the amplified signal
Data Source
AI summary
A power amplifier module includes an amplifier that amplifies an input signal and outputs the amplified signal, a harmonic termination circuit that is disposed subsequent to the amplifier and that attenuates a harmonic component of the amplified signal, the harmonic termination circuit including at least one field effect transistor (FET), and a control circuit that controls a gate voltage of the at least one FET to adjust a capacitance value of a parasitic capacitance of the at least one FET. The control circuit adjusts the capacitance value of the parasitic capacitance of the at least one FET, and thereby a resonance frequency of the harmonic termination circuit is adjusted.