Multi-Input Amplifier Degeneration Matrix for Gain-Mode Linearity
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Solution Overview
Problem
Wireless communication devices face reduced performance in signal amplifiers across various gain modes, particularly in terms of linearity, due to the use of single amplifier cores for all gain modes, which fail to achieve desired noise figures and linearity characteristics.
Innovation Solution
The implementation of a variable-gain signal amplifier with multiple switchable amplifier cores and a degeneration matrix that provides tailored impedances without using switches, allowing for selective direction of signals to dedicated amplifier architectures for specific gain modes, enhancing noise figure and linearity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single amplifier core is used for all gain modes, then the device complexity is reduced, but the linearity and noise figure performance deteriorate across various gain modes
Solution Approach 1:
The amplifier is segmented into multiple dedicated amplifier cores (first amplifier core, second amplifier core) where each core is optimized for specific gain modes. The gain mode selector divides the signal path and directs signals to appropriate amplifier cores based on the required gain mode, allowing each core to specialize in particular performance characteristics such as linearity or noise figure for its designated gain modes.
2Reliability
If multiple dedicated amplifier cores are used for different gain modes, then the linearity and noise figure performance improve, but the device complexity increases
Solution Approach 1:
The degeneration matrix serves multiple functions simultaneously: it provides tailored impedances for different gain modes, enables switching between amplifier cores without using physical switches, and optimizes performance characteristics for each signal path. This multi-functional component reduces overall device complexity despite the presence of multiple amplifier cores.
Solution Approach 2:
The gain mode selector and degeneration matrix are combined into an integrated control mechanism that simultaneously manages signal routing to different amplifier cores and provides appropriate impedance transformation. This merging of functions reduces the number of separate components needed and simplifies the overall amplifier architecture.
3Adaptability or versatility
If switches are used for degeneration switching between amplifier cores, then the adaptability to different gain modes improves, but the device complexity and control logic requirements increase
Solution Approach 1:
The patent replaces mechanical or electronic switches with a degeneration matrix that uses passive impedance transformation to achieve switching between amplifier cores. The gain mode selector controls the degeneration matrix to provide tailored impedances that naturally route signals to the appropriate amplifier core without requiring physical switch closure or complex control logic.
Solution Approach 2:
The degeneration matrix automatically provides the appropriate impedance transformation and signal routing based on the gain mode selected. The system self-adjusts the impedance characteristics to direct signals to the correct amplifier core without requiring external control signals or complex switching logic, making the switching process autonomous and simplifying the overall control architecture.
Data Source
AI summary
Disclosed herein are signal amplifiers that include a plurality of switchable amplifier architectures so that particular gain modes can use dedicated amplifier architectures to provide desired characteristics for those gain modes, such as low noise figure or high linearity. The disclosed signal amplifier architectures provide tailored impedances using a degeneration block or matrix without using switches in the degeneration switching block. The disclosed signal amplifier architectures provide a plurality of gain modes where different gain modes use different paths through the amplifier architecture. Switches that are used to select the path through the amplifier architecture also provide targeted impedances in a degeneration block or matrix. The switches that select the gain path are provided in the amplifier architecture and are thus not needed or used in the degeneration block, thereby reducing the size of the package for the amplifier architecture.