Shared RF Filtering Element for Multi-Band Front End Modules

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Solution Overview

Problem

RF front end modules require a large area due to multiple dedicated RF filtering elements for each operating band, making them bulky and inefficient for servicing multiple frequency bands.

Innovation Solution

Implementing a shared RF filtering element that can isolate signals within different operating bands by configuring the switching circuitry to couple the shared element to the antenna node in various operating configurations, reducing the number of filtering elements needed while maintaining functionality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a dedicated RF filtering element is used for each operating band, then the RF front end module can service multiple operating bands, but the area occupied by the module increases

Engineering Contradiction:

Improvenumber of operating bands servicedVSAvoidarea of RF front end module

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent implements a shared RF filtering element that can be configured to filter multiple different operating bands through switching circuitry. This single filtering element replaces what would traditionally require multiple dedicated filtering elements, thereby reducing the overall area of the RF front end module while maintaining the capability to service multiple operating bands.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines the functionality of multiple dedicated filtering elements into a single shared filtering element. By merging these functions and using switching circuitry to selectively connect the shared element to different antenna nodes, the module achieves multi-band support with reduced component count and smaller area.

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If filtering elements are duplicated for easier impedance matching, then the matching between filtering elements is improved, but the number of filtering elements and overall size increases

Engineering Contradiction:

Improveimpedance matching between filtering elementsVSAvoidnumber of filtering elements

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The shared filtering element is designed to work with switching circuitry that connects it to different antenna nodes corresponding to different operating bands. This universal design eliminates the need for multiple duplicated filtering elements while maintaining proper impedance matching through the switching mechanism.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS11424769B2Radio frequency filtering circuitry with reduced filter set

Publication Date: 2022.08.23 QORVO US INC

AI summary

A radio frequency (RF) front end module includes an antenna node, a number of RF filtering elements and switching circuitry. Each one of the RF filtering elements is configured to pass RF signals within a filter pass band and attenuate RF signals outside the filter pass band. The switching circuitry is configured to selectively couple one or more of the RF filtering elements to the antenna node such that RF signals in different operating bands received at the antenna node are separately isolated by the RF filtering elements. The RF filtering elements include a shared filtering element, which is switchable such that in a first operating configuration is used to isolate signals within a first operating band and in a second operating configuration is used to isolate signals within a second operating band that is different from the first operating band.