Duplexer Layout for High-Isolation Communication Modules

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Solution Overview

Problem

Communication modules with high density circuits face reduced isolation characteristics due to the proximity of transmit and receive signal paths, which is not effectively suppressed by existing duplexer arrangements that integrate transmit and receive filters.

Innovation Solution

A communication module design that includes an input/output switch, a duplexer with specific terminal arrangements, and separate transmit and receive filters, where the duplexer's second side is positioned farther from the input/output switch in a second direction orthogonal to the first direction, and one of the filters is disposed adjacent to the input/output switch in the first direction, allowing for improved isolation characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a duplexer integrates transmit and receive filters, then the number of discrete components is reduced, but isolation characteristics degrade due to proximity of transmit and receive signal paths

Engineering Contradiction:

Improvenumber of discrete componentsVSAvoidisolation characteristics

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent positions the duplexer such that its second side is disposed at a location farther from the input/output switch than the first side in a second direction orthogonal to the first direction. This three-dimensional spatial arrangement creates effective separation between transmit and receive signal paths while maintaining the integrated duplexer structure, thereby improving isolation characteristics without increasing component count

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent specifies that one of the transmit filter or receive filter is disposed adjacent to the input/output switch in the first direction, while the duplexer's second side is positioned farther away in the orthogonal second direction. This creates localized zones with different functional qualities - the first direction handles signal routing proximity while the orthogonal second direction provides isolation spacing

Inventive Principle:

Principle #3Local quality

2Quantity of substance

If transmit and receive filters are disposed close together for high density, then circuit density improves, but signal leakage between paths increases

Engineering Contradiction:

Improvecircuit densityVSAvoidsignal leakage

Core Design Contradiction:

Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent utilizes orthogonal directions for spatial arrangement: the first direction (parallel to duplexer sides) allows compact positioning for high density, while the second direction (orthogonal to first direction) provides the separation distance needed to reduce signal leakage. This dimensional approach enables both high circuit density and low signal interference

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS11258422B2Communication module

Publication Date: 2022.02.22 MURATA MFG CO LTD

AI summary

A communication module includes an input/output switch, a duplexer, a transmit filter, and a receive filter. In the duplexer, a second side is disposed at a position farther from the input/output switch than a first side in a second direction orthogonal to a first direction. Any one of the transmit filter and the receive filter is disposed adjacent to the input/output switch in the first direction.