Tunable Multi-Path RF Filter for Wideband Frequency Coverage
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Solution Overview
Problem
Conventional radio products using surface acoustic wave (SAW) filters are limited to frequencies up to 3 GHz with fixed center frequency and bandwidth, requiring multiple filters for each frequency band, which is inefficient.
Innovation Solution
A tunable multi-path filter with a voltage-controlled current source and an oscillator source generating a tunable clock signal, allowing each filter path to produce output voltage signals based on the current and clock signals, enabling adjustable center frequency and bandwidth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If surface acoustic wave filters are used, then filtering function is provided, but frequency range is limited to 3 GHz and center frequency is fixed
Solution Approach 1:
The patent implements dynamic tuning capability by replacing fixed SAW filters with electronically controllable filters whose center frequency and bandwidth can be adjusted in real-time through control signals, allowing a single filter to adapt to multiple frequency bands
Solution Approach 2:
The patent creates a universal filter system that can handle multiple frequency bands (from 0.1 GHz to 6 GHz) with a single multi-path filter device, eliminating the need for separate dedicated filters for each frequency band
2Adaptability or versatility
If multiple surface acoustic wave filters are used for each frequency band, then frequency coverage is improved, but device complexity and cost increase
Solution Approach 1:
The patent merges multiple filter functions into a single multi-path filter device that processes multiple frequency bands simultaneously through parallel signal paths, reducing the total number of filter components required
Solution Approach 2:
The patent divides the filter into multiple parallel paths that can be independently controlled, allowing each path to handle specific frequency bands while working together to provide comprehensive frequency coverage
Data Source
AI summary
A tunable multi-path filter, a method for filtering a radio frequency signal with the tunable multi-path filter, and a communication device including the tunable multi-path filter. In one embodiment, the tunable multi-path filter includes a voltage controlled current source, an oscillator source, and at least two filter paths. The voltage controlled current source for receiving a radio frequency (RF) signal and generating a current signal. The oscillator source for generating a tunable clock signal. Each of the at least two filter paths are coupled to the voltage controlled current source and the oscillator source, and are configured to generate an output voltage signal based at least in part on the current signal and the tunable clock signal. In some embodiments, the tunable multi-path filter further includes a carrier signal rejection component that is configured to reduce the carrier feedthrough in the output voltage signals.