Switched Multiplexer for Carrier Aggregation Filter Reuse
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Solution Overview
Problem
Conventional mobile devices face challenges in supporting multiple wireless communication bands for carrier aggregation due to the need for multiple copies of filter circuits, leading to increased size and cost, as well as difficulties in impedance matching across different frequency bands.
Innovation Solution
A switched multiplexer device with a multi-state switch that selectively connects combinations of filter circuits and matching networks to a common antenna node, allowing for flexible switching of band combinations and impedance matching, using a single copy of each filter and low Q reactive circuits to replace out-of-band impedance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple copies of filter circuits are used to support all possible band combinations for carrier aggregation, then all band combinations can be supported, but device size and cost increase
Solution Approach 1:
The patent implements a switched multiplexer with a multi-state switch that dynamically connects different filter circuits to the common antenna node based on the required band combination. Instead of having all filters permanently connected, the system dynamically reconfigures the connections to support different carrier aggregation scenarios, reducing the number of simultaneously active filters while maintaining full band combination support capability.
Solution Approach 2:
Each filter circuit is designed to be universally connectable to the common antenna node through the switched multiplexer. The same set of filter circuits can serve multiple different band combinations by being selectively connected in different configurations, making each filter circuit multi-functional rather than dedicated to a single band combination.
2Adaptability or versatility
If multiple copies of filter circuits are used to support all possible band combinations, then carrier aggregation flexibility improves, but manufacturing cost increases
Solution Approach 1:
The switched multiplexer enables dynamic reconfiguration of filter connections without requiring multiple permanent hardware copies. A single set of filter circuits is reused across different band combinations through electronic switching, significantly reducing component count and manufacturing cost while preserving carrier aggregation flexibility.
Solution Approach 2:
The patent merges multiple filter circuits into a single shared pool that serves all band combinations. Instead of manufacturing separate filter sets for each band combination, the system combines all filters into one unified resource that is dynamically allocated based on operational requirements.
3Area of stationary object
If a common antenna node is used for multiple signal paths, then device area is reduced, but impedance matching difficulty increases
Solution Approach 1:
The switched multiplexer acts as an intermediary between the common antenna node and multiple filter circuits. It provides impedance transformation and matching functionality, translating between the antenna's impedance and the impedances of different filter circuits. This mediator role simplifies the impedance matching problem by handling it centrally at the switching point rather than requiring individual matching networks for each filter.
Solution Approach 2:
The switched multiplexer changes the electrical parameters (impedance, connectivity) dynamically based on which filter circuit is connected to the common antenna node. By adjusting the connection state and electrical characteristics according to the active band combination, the system maintains proper impedance matching across different operational configurations.
Data Source
AI summary
A device combines filter circuits to be connected to an antenna, enabling carrier aggregation for wireless communications over multiple RF frequency bands in different operational environments. The device includes first, second and third filter circuits having first, second and third matching networks and one or more first, second and third band pass filters with corresponding passbands, respectively. The device further includes multiple individual matching networks not dedicated to any of the first, second or third filter circuits, and a multi-state switch configured to provide different filter circuit combinations by selectively connecting at least two of the first, second and third filter circuits, respectively, and at least one individual matching network of the multiple matching networks. Each filter circuit combination includes a combined matching network having at least two of the first, second and third matching networks and the at least one individual matching network.