SIMO LNA Noise Splitting for Lower Noise Figure
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Solution Overview
Problem
Current amplifiers face challenges in efficiently supporting carrier aggregation by maintaining good noise performance when simultaneously receiving multiple transmissions, leading to increased noise figures due to noise coupling between amplifier circuits.
Innovation Solution
The implementation of Single-Input Multiple-Output (SIMO) Low Noise Amplifiers (LNAs) with noise splitting, where noise is distributed among multiple outputs, reducing the noise power at each load circuit and improving the noise figure by shorting the outputs of multiple amplifier circuits together.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple amplifier circuits are used to support carrier aggregation, then the ability to simultaneously receive multiple transmissions is improved, but noise coupling between amplifier circuits increases the noise figure
Solution Approach 1:
The patent divides the noise figure into separable components by introducing auxiliary amplifier circuits that process only noise signals. This segmentation allows the main amplifier circuits to handle signal paths independently while dedicated auxiliary circuits handle noise paths, preventing noise coupling between signal paths and enabling carrier aggregation without penalty to noise figure.
2Productivity
If multiple amplifier circuits are used for simultaneous reception, then carrier aggregation is supported, but the noise power at each load circuit increases
Solution Approach 1:
The patent introduces auxiliary amplifier circuits as intermediary elements that process noise signals separately from the main signal paths. These auxiliary circuits act as mediators that extract and process noise components, preventing noise from coupling between multiple amplifier circuits and maintaining lower noise power at each load circuit while supporting simultaneous reception.
3Object-affected harmful factors
If amplifier circuits are configured for noise splitting, then noise figure is improved, but device complexity increases
Solution Approach 1:
The patent merges the noise processing function into the existing amplifier circuit structure by adding auxiliary amplifier circuits that are integrated with the main signal paths. This merging approach implements noise splitting without requiring completely separate noise processing subsystems, thereby improving noise figure while limiting the increase in device complexity.
Data Source
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AI summary
Amplifiers with noise splitting to improve noise figure are disclosed. In an exemplary design, an apparatus (e.g., a wireless device, an integrated circuit, etc.) includes a plurality of amplifier circuits (550a, 550b, 550m) and at least one interconnection circuit (580a, 580b). The amplifier circuits (550a, 550b, 550m) receive an input radio frequency signal (RFin). The interconnection circuits (580a, 580b) are coupled between the plurality of amplifier circuits (550a, 550b, 550m). Each interconnection circuit (580a, 580b) is closed to short the outputs or internal nodes of two amplifier circuits coupled to that interconnection circuit (580a, 580b). The plurality of amplifier circuits (550a, 550b, 550m) may include a plurality of gain circuits (560a, 560b, 560m) coupled to a plurality of current buffers (570a, 570b, 570m), one gain circuit and one current buffer for each amplifier circuit.