Multifinger Power Amplifier Gate Inductance Compensation
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Solution Overview
Problem
Conventional power amplifiers with multifinger transistors face inefficiency due to varying gate-to-source voltages among gate fingers, as the distance from the higher harmonic processing circuit to each finger differs, preventing uniform efficiency improvement.
Innovation Solution
A power amplifier design with a multifinger transistor where source and drain fingers are alternately arranged, and a line is attached to the source fingers to cause a phase rotation, making gate fingers closer to the center more inductive, thereby equalizing gate-to-source voltage amplitudes and phases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a higher harmonic processing circuit is attached to the input side to short-circuit the impedance for the second harmonic wave, then the power loss in the higher harmonic wave is suppressed and efficiency is improved, but the voltage between gate and source at each gate finger differs due to different distances from the processing circuit, preventing uniform efficiency improvement across all fingers
Solution Approach 1:
The patent applies local quality by making each gate finger have different inductance values according to its position. Gate fingers closer to the central part are made more inductive, while those farther away are less inductive. This localized adjustment compensates for the distance difference from the higher harmonic processing circuit, ensuring uniform voltage distribution and efficiency improvement across all gate fingers.
Solution Approach 2:
The patent changes the inductance parameter of the gate fingers based on their position. By adjusting the inductance value for each gate finger according to its distance from the central part, the patent compensates for the varying electrical characteristics and achieves uniform gate-to-source voltage across all fingers, resolving the contradiction between efficiency improvement and uniform voltage distribution.
2Ease of operation
If the distances from the higher harmonic processing circuit to different gate fingers are different, then the voltage between gate and source varies among fingers, but making all gate fingers equally inductive would require complex additional circuitry
Solution Approach 1:
The patent merges the phase rotation function into the existing gate finger structure by integrating inductors directly into the gate finger connections. This combination eliminates the need for separate external phase rotation circuits while achieving uniform voltage distribution, thus reducing device complexity while maintaining ease of operation.
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 design enhances the power amplifier's efficiency by uniformly compensating phase and voltage differences among gate fingers, allowing for optimal higher harmonic processing and improved power amplification.
Implementation Method 1
a line attached to the plurality of source fingers in an area on a gate side and causing a phase rotation such that the nearer to a central part, being on a signal input end side, of the plurality of gate fingers a gate finger is, the more inductive the gate finger is
Data Source
AI summary
A multifinger transistor in which source fingers (201 to 206) and drain fingers (301 to 305) are arranged alternately with each of gate fingers (101 to 110) being sandwiched between one of the source fingers and one of the drain fingers is used. Line (10) and line (20) are attached to the source fingers (201 to 206) in an area on a gate side and causing a phase rotation such that the nearer to a central part a gate finger is, the more inductive the gate finger is.