Wideband Tunable Filter for Interference Suppression
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Solution Overview
Problem
Conventional methods for reducing radio frequency interference (RFI) in wireless communications are inefficient, particularly in handling wideband interference, and often result in signal distortion or require costly and complex materials, limiting their use in consumer products.
Innovation Solution
A wideband frequency and bandwidth tunable filter system that includes a splitter, modifier blocks, an adjustment circuit, and a compensation device to adjust phase and amplitude of input signals, allowing for effective filtering of wideband interference while minimizing distortion and maintaining signal integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional filtering methods (band-stop or notch filters) are used to suppress interference at a particular frequency, then narrowband interference is removed, but wideband interference cannot be effectively removed and multiple filters are required increasing cost
Solution Approach 1:
The filter is divided into multiple parallel filter sections, each handling a specific frequency segment. This segmentation allows the system to process wideband interference by combining the outputs of multiple sections, each optimized for its frequency range, thereby achieving effective wideband suppression without requiring a single complex filter.
Solution Approach 2:
The filter system is designed to handle multiple types of interference (narrowband and wideband) using the same basic architecture. By adjusting the tuning elements in different filter sections, the system can adapt to suppress various interference patterns, making it universally applicable to different interference scenarios without requiring separate specialized filters.
2Object-affected harmful factors
If band-stop filters are used to remove interference at a particular frequency, then interference is suppressed, but the desired signal at the same frequency is also removed
Solution Approach 1:
Each filter section is designed with specific local characteristics tailored to its frequency range. The tuning elements in each section can be independently adjusted to create nulls at specific interference frequencies while maintaining passband characteristics for the desired signal. This local optimization allows selective suppression of interference without affecting the desired signal.
Solution Approach 2:
The filter system employs tunable elements that can dynamically adjust their characteristics based on the detected interference pattern. This dynamic adjustment allows the filter to adaptively place nulls at interference frequencies while maintaining signal integrity for the desired communication signal, preventing the simultaneous removal of both interference and desired signal.
3Reliability
If Type III-IV semiconductor materials such as gallium nitride are used to tolerate higher power levels, then distortion is reduced, but cost and complexity significantly increase
Solution Approach 1:
The patent replaces the need for high-power tolerant semiconductor materials with a signal processing approach using tunable filters. Instead of relying on expensive GaN materials to handle high power, the system uses adjustable filter sections with tuning elements to manage interference, thereby reducing both cost and complexity while maintaining distortion-free operation.
Solution Approach 2:
The filter system changes the operating parameters (frequency, phase, amplitude) of the filter sections dynamically to achieve the desired filtering effect. By adjusting the tuning elements, the system can optimize performance for different interference conditions without requiring expensive high-power materials, thus reducing cost and complexity while maintaining reliability.
4Ease of manufacture
If CMOS materials are used in consumer products, then cost is reduced, but distortion sensitivity increases requiring operation at reduced power
Solution Approach 1:
The tunable filters perform preliminary filtering of interference signals before they reach the vulnerable CMOS receiver circuits. By preemptively removing wideband and narrowband interference through the parallel filter sections, the system protects the cost-sensitive CMOS components from distortion, allowing them to operate at higher power levels without sacrificing reliability.
Data Source
AI summary
Methods, systems, and computer readable media for wideband frequency and bandwidth tunable filtering are disclosed. According to one aspect, the subject matter described herein includes a wideband frequency and bandwidth tunable filter that splits a filter input signal into first and second input signals, modifies the first input signal to produce a first output signal, modifies the second input signal to produce a second output signal having an intermediate frequency response, and combines the first and second output signals while adjusting their relative phases and/or amplitudes to produce a filter output signal with the target frequency response. Adjustment includes splitting the second input signal into third and fourth input signals, which are modified and then combined to produce the second output signal having the intermediate frequency response.