Split-Band RF Multiplexer for Low-Loss Carrier Aggregation

Solution Overview

Problem

Current RF front-end module designs face challenges in achieving lower cost and smaller size while maintaining performance, particularly in carrier aggregation scenarios where additional loss and complexity arise due to the need for multiple filters and power amplifiers to support multiple bands simultaneously.

Innovation Solution

The implementation of a switched multiplexer system that includes an assembly of filters and a switching circuit, allowing for simultaneous operation of multiple filtered paths with an antenna port, and the use of phase shifting and impedance matching circuits to reduce insertion loss and increase flexibility in band aggregation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple filters and power amplifiers are used to support multiple bands simultaneously, then carrier aggregation capability is improved, but device size and cost increase

Engineering Contradiction:

Improvecarrier aggregation capabilityVSAvoiddevice size

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent combines multiple filter functions into a single multiplexer device that can handle multiple bands (e.g., B1, B3, B4) simultaneously. The multiplexer integrates what would traditionally require separate filters and duplexers into one unified component, reducing the overall number of parts needed in the RF front-end module.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The multiplexer is designed to perform multiple functions: it provides filtering for different bands, enables carrier aggregation across multiple bands, and replaces traditional duplexer functionality. This multi-functional design eliminates the need for separate dedicated components for each band, thereby reducing device size and component count.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If multiple filters and power amplifiers are used to support multiple bands simultaneously, then carrier aggregation capability is improved, but device cost increases

Engineering Contradiction:

Improvecarrier aggregation capabilityVSAvoiddevice cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent combines multiple filter functions into a single multiplexer device that can handle multiple bands (e.g., B1, B3, B4) simultaneously. The multiplexer integrates what would traditionally require separate filters and duplexers into one unified component, reducing the overall number of parts needed in the RF front-end module.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The multiplexer is designed to perform multiple functions: it provides filtering for different bands, enables carrier aggregation across multiple bands, and replaces traditional duplexer functionality. This multi-functional design eliminates the need for separate dedicated components for each band, thereby reducing device size and component count.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If traditional filter configurations are used for carrier aggregation, then filtering performance is maintained, but insertion loss increases

Engineering Contradiction:

Improvefiltering performanceVSAvoidinsertion loss

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The multiplexer employs switching mechanisms that dynamically connect different filter paths based on the active carrier aggregation configuration. This dynamic switching allows the system to optimize the signal path and minimize insertion loss by activating only the necessary filter paths for the current operating mode, rather than having all filters permanently connected.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The filtering function is segmented into multiple independent paths within the multiplexer, each optimized for specific band combinations. This segmentation allows the system to activate only the relevant filter segments needed for the current carrier aggregation mode, reducing overall insertion loss compared to a monolithic filter configuration where all paths are always active.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS11038543B2Carrier aggregation using split band filters

Publication Date: 2021.06.15 SKYWORKS SOLUTIONS INC

AI summary

Improved switched multiplexer architecture for supporting carrier aggregation in front-end applications. Front end architectures are disclosed that use two filters for a particular frequency band to allow for carrier aggregation using bands that at least partially overlap in frequency. An antenna switch module can be used to independently couple individual filters to an antenna to support a variety of carrier aggregation modes. Switches that connect to the two filters that split the particular frequency band can be configured to operate independently so as to only pass signals within a sub-band of the particular frequency band when operating in certain carrier aggregation modes.