Adaptive RF Front-End Circuit with Dynamic Shunt Rejection
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Solution Overview
Problem
Conventional RF front-end designs in wireless devices suffer from high insertion loss due to the use of high-Q band-pass filters, which are overkill for scenarios where aggressor bands are not close to victim bands, leading to degraded performance and increased power loss in desired signals.
Innovation Solution
An adaptive RF front-end circuit with a multi-way switch and shunt circuit that provides varying levels of rejection, allowing for a bypass path in non-critical scenarios to reduce insertion loss and using higher rejection paths only when necessary in critical scenarios, thereby optimizing filter usage based on coexistence scenarios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a high-Q band-pass filter is used to reject close-in aggressor bands, then the rejection of aggressor bands is improved, but the insertion loss of the desired signal increases
Solution Approach 1:
The patent implements a dynamic filter selection mechanism where the RF front-end circuit can switch between different filter configurations based on the detected coexistence scenario. The system dynamically adjusts whether to insert a high-Q band-pass filter or use a bypass path, transforming the static filter architecture into a dynamic one that adapts to real-time spectral conditions.
Solution Approach 2:
The patent changes the operational parameters of the RF front-end by introducing multiple filter options with different Q factors and insertion loss characteristics. The system selects appropriate filter parameters (high-Q for critical scenarios, low-Q or bypass for non-critical scenarios) based on the spectral environment, thereby optimizing the balance between rejection and insertion loss.
2Object-affected harmful factors
If a high-Q band-pass filter is used in all scenarios, then the rejection of close-in aggressor bands is maintained, but the performance of the wireless system degrades in non-critical scenarios
Solution Approach 1:
The system dynamically adapts its filter configuration based on real-time detection of coexistence scenarios. By switching between high-Q filter mode, low-Q filter mode, and bypass mode, the system maintains high rejection only when necessary (critical scenarios) while preserving system performance in non-critical scenarios where aggressor bands are not present or are sufficiently isolated.
Solution Approach 2:
The patent introduces multiple filter configurations with different rejection characteristics and enables dynamic selection based on spectral conditions. This allows the system to adjust the rejection parameter adaptively - using high rejection only when close-in aggressor bands are detected, and reducing rejection (or bypassing filters) when they are not present, thereby maintaining overall system reliability.
3Device complexity
If a fixed filter position is used to address all coexistence scenarios, then the design is simple, but the insertion loss increases when high rejection is not needed
Solution Approach 1:
The patent transforms the fixed filter architecture into a dynamic one by introducing switching mechanisms that can selectively connect or disconnect filters based on operational needs. This dynamic approach adds moderate complexity but enables the system to avoid unnecessary insertion loss by bypassing filters when high rejection is not required.
Solution Approach 2:
The RF front-end circuit is designed with multi-functionality, incorporating both filtering and bypass capabilities within a single architecture. The system can universally handle both critical scenarios (requiring high rejection) and non-critical scenarios (where bypass is sufficient) using the same hardware platform, thereby avoiding the need for separate fixed-filter designs for different scenarios.
Data Source
AI summary
A radio frequency (RF) front-end circuit has a multi-way switch, an output terminal, and a shunt circuit. The multi-way switch has an input end, a plurality of output ends, and a control end. The input end is coupled to an antenna for receiving a radio frequency signal from the antenna. The control end is used to couple the input end to one of the output ends according to a switch control signal. The shunt circuit is coupled between the multi-way switch and the output terminal to provide one of shunt paths according to the switch control signal. The shunt paths correspond to different amounts of rejection to the radio frequency signal.