RF Module Signal Path Isolation for Simultaneous Tx/Rx Sensitivity

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing radio-frequency modules experience degradation in reception sensitivity when transmission and reception signals are simultaneously processed in different frequency bands due to overlapping attenuation characteristics of transmission and reception filters, leading to signal interference and noise.

Innovation Solution

A radio-frequency module design that includes a switchable configuration with a third filter attenuating the transmission signal's frequency band, a bypass path for the reception signal, and separate paths for transmission and reception signals to prevent interference and maintain sensitivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If transmission and reception filters are connected in common via diplexer and switch, then simultaneous transmission and reception in different frequency bands is enabled, but reception sensitivity degrades when transmission signal frequency band overlaps with reception filter attenuation band

Engineering Contradiction:

Improvesimultaneous transmission and reception capabilityVSAvoidreception sensitivity

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent divides the signal path into separate segments: transmission path, reception path, and isolation path. By segmenting the filter connection and introducing a dedicated isolation filter in the reception path, the system prevents transmission signal leakage from degrading reception sensitivity while maintaining simultaneous transmission and reception capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces a third filter (isolation filter) as an intermediary component in the reception signal path. This filter specifically attenuates the transmission signal frequency band, acting as a mediator to block harmful interference from the transmission signal while allowing the reception signal to pass through.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If reception filter attenuation characteristics are insufficient in transmission signal frequency band, then simultaneous transmission and reception can be performed, but transmission signal leaks into reception circuit and degrades reception sensitivity

Engineering Contradiction:

Improvesimultaneous signal processing capabilityVSAvoidsignal leakage and interference

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary anti-action by pre-attenuating the transmission signal frequency band in the reception path using the third filter. This prevents the harmful effect of signal leakage before it can reach the reception circuit, countering the insufficient attenuation characteristics of the reception filter.

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The patent converts the harmful transmission signal leakage into a beneficial isolation mechanism. By deliberately adding a filter that targets the transmission frequency band in the reception path, the system transforms the potential harm of frequency overlap into a controlled isolation mechanism that protects reception sensitivity.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution effectively suppresses the degradation of reception sensitivity by isolating the transmission signal's interference, allowing for simultaneous transmission and reception with reduced signal loss and improved sensitivity across multiple frequency bands.

Implementation Method 1

a third filter that has the transmission band as an attenuation band and is connected between the second selection terminal and the first reception filter

Methodology Applied

Scientific EffectFilter (electronic): Filter (electronic)

Data Source

PatentUS11483019B2Radio-frequency module and communication device

Publication Date: 2022.10.25 MURATA MFG CO LTD

AI summary

A radio-frequency module includes a switch performing switching of the connection between a common terminal and a selection terminal, a reception filter having a reception band in a band A as a passband, a transmission filter that has a transmission band in a band B as a passband and has an output terminal connected to the selection terminal, a filter that has the transmission band in a band B as an attenuation band and has an input terminal connected to the selection terminal, a reception path which connects the selection terminal and an input terminal of the reception filter and on which the filter is disposed, a bypass path which connects the selection terminal and the input terminal of the reception filter and on which no filter is disposed, and a transmission path which connects the selection terminal and a transmission terminal and on which the transmission filter is disposed.