Non-Uniform Harmonic Trap Filter for RF Amplifier Distortion
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Solution Overview
Problem
Existing RF amplifiers face challenges in effectively suppressing harmonic frequencies, leading to waveform distortion due to non-uniform input drive currents and mutual inductances, which are not adequately addressed by conventional harmonic filters.
Innovation Solution
Implementing a harmonic trap filter with an array of shunt filter legs having a non-uniform resonance frequency distribution, where edges and center shunt filter legs have different resonance frequencies, coupled with dampening resistors to mitigate distortions and improve input drive uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional harmonic filters with uniform resonance frequency distribution are used, then the filter structure is simple and easy to manufacture, but the harmonic suppression is insufficient and input drive uniformity is poor
Solution Approach 1:
The patent applies local quality by creating non-uniform resonance frequency distribution across different spatial locations of the filter legs. Specifically, filter legs at different positions (edge vs center) are designed with different resonance frequencies to match the local current distribution characteristics, thereby improving harmonic suppression performance in different regions of the amplifier device.
Solution Approach 2:
The patent implements asymmetry by deliberately designing the filter leg resonance frequencies to be asymmetrically distributed rather than uniform. The edge filter legs have different resonance frequencies compared to center filter legs, creating an asymmetric frequency distribution that compensates for the non-uniform current distribution in the amplifier device.
2Manufacturing precision
If uniform resonance frequency distribution is used in shunt filter legs, then the design and manufacturing is simpler, but input drive uniformity and harmonic suppression are degraded
Solution Approach 1:
The patent applies local quality by creating non-uniform resonance frequency distribution across different spatial locations of the filter legs. Specifically, filter legs at different positions (edge vs center) are designed with different resonance frequencies to match the local current distribution characteristics, thereby improving harmonic suppression performance in different regions of the amplifier device.
Solution Approach 2:
The patent changes the resonance frequency parameter of the shunt filter legs from uniform to non-uniform distribution. By adjusting the resonance frequencies of individual filter legs based on their positions, the patent achieves improved input drive uniformity and harmonic suppression without requiring complex manufacturing processes.
3Reliability
If conventional harmonic filters are used, then the device structure is simpler, but waveform distortion occurs due to inadequate harmonic blocking
Solution Approach 1:
The patent applies local quality by creating non-uniform resonance frequency distribution across different spatial locations of the filter legs. Specifically, filter legs at different positions (edge vs center) are designed with different resonance frequencies to match the local current distribution characteristics, thereby improving harmonic suppression performance in different regions of the amplifier device.
Solution Approach 2:
The patent segments the filter into multiple shunt filter legs with individually optimized resonance frequencies. Instead of using a single uniform filter structure, the patent divides the filter into discrete legs that can be independently designed and tuned to address specific harmonic suppression requirements at different locations.
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 non-uniform resonance frequency distribution enhances the suppression of harmonic frequencies, mitigating distortions and improving RF amplifier performance by uniformizing input drive currents, thereby enhancing overall amplifier efficiency.
Implementation Method 1
A first set of shunt filter legs of the array of shunt filter legs near edges of the array of shunt filter legs may have first resonance frequencies that are lower than second resonance frequencies of a second set of shunt filter legs of the array of shunt filter legs near a center of the array of shunt filter legs
Data Source
AI summary
An RF amplifier includes at least one harmonic trap filter with an array of shunt filter legs having a non-uniform resonance frequency distribution. The harmonic trap filter is configured to suppress frequencies in a suppression frequency range that includes harmonic frequencies of carrier frequencies in a range of carrier frequencies. Each of the shunt filter legs includes a capacitor and inductor coupled in series, and an intermediate node coupled between the capacitor and the inductor. Each intermediate node of the shunt filter leg is coupled to at least one other intermediate node of another shunt filter leg of the filter with a dampening resistor. Shunt filters at or near edges of the array are configured to have lower resonance frequencies than those at or near the center of the array to suppress excess current flow at edges of the RF amplifier.