Duplexer Filter Layout for Overlapping Transmit and Receive Bands

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Solution Overview

Problem

Existing filter devices for communication bands with overlapping frequency bands require complex configurations due to the need for individual filters for each overlapping band, leading to increased complexity and cost.

Innovation Solution

A filter device with a simple configuration that uses a single input and output unit, employing a fixed frequency band that encompasses both overlapping communication bands, eliminating the need for separate filters for each band, and incorporating a duplexer or multiplexer to handle both transmit and receive signals within a single communication band.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If individual filters are used for each overlapping communication band, then signal handling for each band is effective, but device complexity increases

Engineering Contradiction:

Improvesignal handling effectivenessVSAvoidfilter device complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple filters designed for different overlapping communication bands into a single integrated filter device. This single filter device has a pass band that covers the frequency range of multiple bands simultaneously, eliminating the need for separate filters for each band while maintaining effective signal handling across all bands.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single filter device is designed to perform multiple functions by handling signals from different overlapping communication bands within a unified structure. The filter device serves as a universal component that can process signals for Band 28A, Band 28B, and potentially other bands without requiring band-specific filter units.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Manufacturing precision

If multiple filters are used for overlapping bands, then frequency selection is precise, but manufacturing cost increases

Engineering Contradiction:

Improvefrequency selection precisionVSAvoidmanufacturing cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent merges multiple band-specific filters into a single filter device, reducing the total number of components that need to be manufactured, assembled, and tested. This consolidation lowers manufacturing costs while maintaining precise frequency selection through the carefully designed pass band that covers all required communication bands.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If separate filters are used for each band, then signal filtering is effective, but the number of components increases

Engineering Contradiction:

Improvesignal filtering effectivenessVSAvoidnumber of filter components

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent consolidates multiple filter components into a single integrated filter device, reducing the quantity of discrete components in the system. This single filter device maintains effective signal filtering for all overlapping bands through its unified pass band design.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS11245385B2Filter device and radio frequency module

Publication Date: 2022.02.08 MURATA MFG CO LTD

AI summary

A duplexer included in a radio frequency module is used in a communication band in which the transmit band in a single communication band includes a first transmit band and a second transmit band overlapping each other and in which the receive band in the single communication band includes a first receive band and a second receive band overlapping each other. A transmit filter unit in the duplexer uses, as a pass band, a fixed frequency band including the first transmit band and the second transmit band. A receive filter unit of the duplexer uses, as a pass band, a fixed frequency band including the first receive band and the second receive band.