Cascaded LNA Switching Matrix for Carrier Aggregation Routing
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Solution Overview
Problem
Conventional split LNA architectures for carrier aggregation in wireless devices face challenges in achieving low noise figure and high linearity with limited power consumption and area usage, leading to complex signal routing and degraded receiver performance as the number of carrier combinations increases.
Innovation Solution
A cascaded switching matrix module is introduced to route outputs of a first plurality of low noise amplifiers to a second plurality, providing flexible routing and reducing parasitic loading and system complexity, with a cascaded switch configuring a 'single input and single output' topology to connect selected inputs and outputs, improving receiver sensitivity and noise figure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a split LNA architecture is used to facilitate intra non-contiguous carrier aggregation, then the ability to process multiple non-contiguous carrier signals is improved, but signal routing complexity and receiver performance degradation increase
Solution Approach 1:
The LNA architecture is segmented into multiple independent LNA paths, each dedicated to specific carrier frequencies. This segmentation allows each LNA to be optimized for its specific frequency range while maintaining independence from other carrier paths, thereby reducing the complexity of signal routing between carriers.
Solution Approach 2:
The patent implements a universal LNA structure where identical or similar LNA circuits can handle multiple different carrier frequencies. This multi-functionality reduces the need for complex routing between specialized LNAs, as the same LNA design can be reused across different frequency bands with minimal reconfiguration.
2Productivity
If the number of carrier combinations increases to support higher downlink data rates, then wireless communication capability is improved, but signal routing complexity and chip area increase
Solution Approach 1:
The receiver is segmented into multiple independent processing paths, each handling specific carrier combinations. This allows the system to support multiple carrier aggregations simultaneously without requiring a completely new routing structure for each combination, thereby scaling efficiently with increased chip area requirements.
Solution Approach 2:
The patent employs parameter changes in the LNA design, such as adjustable gain and frequency tuning capabilities, to accommodate different carrier combinations. This flexibility allows the same hardware structure to support multiple carrier aggregations without proportionally increasing chip area, as the LNAs can be reconfigured for different frequency pairs.
3Adaptability or versatility
If conventional split LNA architecture is used, then intra non-contiguous carrier aggregation is enabled, but noise figure and linearity performance deteriorate
Solution Approach 1:
By segmenting the receiver into dedicated LNA paths for different carriers, each LNA operates independently with optimized matching and impedance control. This reduces signal interference and maintains better noise figure and linearity performance compared to shared routing architectures where signals from multiple carriers compete for the same path.
Solution Approach 2:
The patent introduces intermediary components such as isolators and matching networks between LNAs and subsequent processing stages. These intermediaries prevent signal reflections and impedance mismatches from degrading performance, thereby maintaining low noise figure and high linearity even when multiple carriers are processed simultaneously.
Data Source
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AI summary
An apparatus includes a first plurality of low noise amplifiers (LNAs) and a cascaded switch configured to route outputs of the first plurality of LNAs to a second plurality of LNAs.