Adjustable Filter Switching via Parallel Paths and Multiplexing

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing filters face performance degradation due to disturbances introduced when adjusting frequency response, particularly in switched circuit elements, which affect system stability during transition periods.

Innovation Solution

An adjustable filter design incorporating multiple filters with distinct frequency responses and a multiplexing circuit controlled by a control signal, allowing seamless switching between output signals without significant disturbance, achieved by ensuring low output impedance of filters and high input impedance of the load circuit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a switched circuit element is used to adjust filter frequency response, then the filter response can be adjusted, but disturbances are introduced to the system during switching transitions

Engineering Contradiction:

Improvefilter frequency response adjustmentVSAvoidsystem stability during transition

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The filter is divided into multiple parallel filter paths (first filter path with first frequency response, second filter path with second frequency response), each processing the input signal independently. The multiplexing circuit then selects between these segmented paths based on control signals, avoiding the need to switch within a single filter circuit and thereby eliminating transition disturbances.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A multiplexing circuit is introduced as an intermediary component between the parallel filter paths and the output. This multiplexing circuit selects filtered signals from different paths based on control signals without causing disturbances to the filter operation, effectively mediating the selection process while maintaining system stability.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If multiple filters with distinct frequency responses are used, then seamless switching between frequency responses is achieved, but device complexity increases

Engineering Contradiction:

Improvefrequency response selectionVSAvoidnumber of filter paths and multiplexing circuit

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Each filter path is designed to process the common input signal independently to produce a filtered signal with a specific frequency response. The multiplexing circuit universally selects from these multiple paths based on control signals, allowing a single system to provide multiple frequency response options without requiring separate processing chains for each response type.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS9083299B2Filter of adjustable frequency response and method thereof

Publication Date: 2015.07.14 REALTEK SEMICON CORP

AI summary

A filter of an adjustable frequency response comprises a plurality of filters having a plurality of distinct frequency responses, respectively. These filters receive a common input signal and generate a plurality of intermediate signals, respectively. A multiplexing circuit is used to select one of these intermediate signals as a filtered signal. The multiplexing circuit is controlled by a control signal that is related to a state of the filtered signal.