Magnetically Coupled LNA Inductors for Multi-Gain Impedance Matching
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Solution Overview
Problem
Low-noise amplifiers face challenges in achieving impedance matching and linearity across different gain modes, leading to decreased wireless communication performance due to the inability to dynamically adjust impedance matching and linearity according to varying gain requirements.
Innovation Solution
The integration of three or more magnetically-coupled inductors within the low-noise amplifier allows for gain-dependent impedance matching and linearity by changing the input impedance across different gain modes, reducing losses and noise levels, thereby improving wireless communication performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the low-noise amplifier uses fixed impedance matching for a specific gain mode, then impedance matching and linearity are improved for that gain mode, but performance deteriorates when operating in other gain modes
Solution Approach 1:
The patent implements dynamic impedance matching by making the matching network adjustable across different gain modes. Switches connect different inductor values to the input terminal, allowing the impedance matching network to be reconfigured dynamically. This enables the amplifier to maintain optimal impedance matching and linearity when transitioning between different gain settings, resolving the contradiction between fixed-performance optimization and multi-mode adaptability.
2Reliability
If the low-noise amplifier uses separate impedance matching networks for different gain modes, then impedance matching is improved across gain modes, but device complexity increases
Solution Approach 1:
The patent creates a universal impedance matching network that serves multiple gain modes through a single reconfigurable structure. Rather than implementing separate matching networks for each gain mode, the invention uses one matching network with switches that can connect different inductor values based on the desired gain mode. This multi-functional approach maintains optimal impedance matching across all gain modes while avoiding the complexity of multiple separate networks.
Solution Approach 2:
The patent changes the inductance parameter of the matching network dynamically based on the gain mode. By switching between different inductor values (L1, L2, L3) connected to the input terminal, the impedance characteristics of the matching network are adjusted to match the optimal values for different gain settings. This parameter change approach enables a single network to perform the function of multiple fixed networks with reduced complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enables improved impedance matching and linearity across different gain modes, maintaining similar performance across various gain settings and enhancing communication efficiency by reducing noise and losses.
Implementation Method 1
The at least two degeneration inductors are configured to establish a magnetic coupling with the input inductor. The at least two degeneration inductors are also configured to establish another magnetic coupling between each other.
Data Source
AI summary
An integrated circuit is disclosed for gain-dependent impedance matching and linearity. The integrated circuit includes at least two amplifier branches, an input inductor, and at least two degeneration inductors. Each amplifier branch includes a node, an input transistor, and a cascode stage connected between a drain of the input transistor and the node. Respective nodes of the at least two amplifier branches are connected together and respective gates of the input transistors of the at least two amplifier branches are connected together. The input inductor is connected to the respective gates, and the at least two degeneration inductors are connected between respective sources of the input transistors of the at least two amplifier branches and a ground. The at least two degeneration inductors are configured to establish a magnetic coupling with the input inductor and establish another magnetic coupling between each other.