Low-Noise Amplifier Topology for Carrier Aggregation Gain Control
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Solution Overview
Problem
Existing low noise amplifiers (LNAs) face challenges in efficiently supporting variously arranged frequency channels due to the large size of source degeneration inductors, which affect gain and occupy significant area, especially in non-contiguous intra-band carrier aggregation modes.
Innovation Solution
The LNA design includes multiple amplifier stages with individually allocated source degeneration inductors for each path, allowing independent control of gain and reducing the overall area by sharing inductors between stages, thereby supporting different carrier aggregation modes efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If source degeneration inductors are allocated for each path to control gain independently, then gain characteristics are improved, but area occupied by inductors increases
Solution Approach 1:
The patent merges the source degeneration inductors of the first and second gain stages into a single shared inductor. This allows both gain stages to independently control their gain characteristics while occupying less area than if separate inductors were used for each stage.
Solution Approach 2:
The shared source degeneration inductor serves multiple functions by being common to both the first and second gain stages. It provides source degeneration for both stages simultaneously, enabling each stage to operate independently while sharing a common component.
2Adaptability or versatility
If multiple amplifier stages are used to support variously arranged frequency channels, then adaptability is improved, but device complexity increases
Solution Approach 1:
The patent combines multiple amplifier stages (first and second gain stages) into a single integrated LNA structure with shared components. This reduces the overall device complexity while maintaining the ability to support variously arranged frequency channels through carrier aggregation.
Solution Approach 2:
The LNA is designed with universal functionality to handle multiple carrier aggregation modes (inter-band, contiguous intra-band, and non-contiguous intra-band) through a unified multi-stage architecture, rather than requiring separate amplifiers for each mode.
3Area of stationary object
If source degeneration inductors are reduced in size to decrease area, then area is reduced, but gain characteristics deteriorate
Solution Approach 1:
By merging the source degeneration inductors of multiple gain stages into a single shared inductor, the patent achieves area reduction while maintaining gain characteristics. The shared inductor is optimally designed to provide appropriate degeneration for both stages simultaneously.
Solution Approach 2:
The patent optimizes the parameters of the shared source degeneration inductor to achieve the right balance between area and gain characteristics. By carefully selecting the inductor value and configuration, both area is reduced and gain characteristics are maintained across different operating conditions.
Data Source
AI summary
A low noise amplifier includes a first input port configured to receive a first input signal, a second input port configured to receive a second input signal, and a first amplifier stage including a first gain stage connected to the first input port and the second input port, and a first drive stage between the first gain stage and a first load circuit. The first gain stage includes a first-first gain block connected to the first input port, a first-second gain block connected to the second input port, and a first degeneration inductor between a ground terminal and a first common node of the first-first gain block and the first-second gain block. The amplifier includes a second amplifier stage including a second gain stage connected to the first input port and the second input port, and a second drive stage between the second gain stage and a second load.