Switched-Capacitor Low-Noise Amplifier for Low-Gain Linearity
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Solution Overview
Problem
Conventional low-noise amplifiers face challenges in achieving uniform gain spacings and high linearity, particularly at low-gain levels, with passive structures affecting signal phase and active structures increasing power consumption without satisfactory results.
Innovation Solution
A high-linearity low-noise amplifier design incorporating a primary-stage and secondary-stage amplification unit, a switched capacitor branch, and configurable load units, utilizing bias voltage control and capacitor voltage cancellation to achieve uniform gain and improved linearity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a passive structure signal path is used to improve linearity at low-gain level, then linearity is improved, but signal phase is changed and gain spacings become non-uniform
Solution Approach 1:
The patent changes the structural parameters of the amplification units by introducing switched capacitor branches and configurable load units. By adjusting the switching states of these components, the circuit can operate in different modes (high-gain/low-linearity and low-gain/high-linearity) while maintaining uniform gain spacings and signal phase characteristics across frequency points.
2Reliability
If bias voltage of amplifying tube is raised to improve linearity in active structure, then linearity is improved to some extent, but power consumption increases
Solution Approach 1:
The patent implements dynamic control of the amplification circuit by using switching transistors and configurable load units that can be adjusted in real-time. The circuit dynamically switches between different amplification paths and loading conditions based on the required gain level, achieving high linearity at low-gain levels without requiring continuous high bias voltage, thus reducing overall power consumption.
3Adaptability or versatility
If active structure is used to provide gain coverage range, then gain coverage is achieved, but linearity at low-gain levels remains insufficient
Solution Approach 1:
The patent segments the amplification function into multiple parallel paths: a primary-stage amplification unit and one or more secondary-stage amplification units. Each unit can be independently controlled through switching mechanisms. By selectively activating different segments based on the required gain level, the circuit achieves wide gain coverage while maintaining high linearity at low-gain levels through the switched capacitor branch configuration.
Data Source
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AI summary
Disclosed are a high-linearity low-noise amplifier, a chip, and an electronic device. The low-noise amplifier comprises a primary-stage amplification unit, at least one secondary-stage amplification unit, a drive unit, a configurable load unit, an input impedance matching unit and an output impedance matching unit, and further comprises a switched capacitor branch; wherein the input end of the at least one secondary-stage amplification unit is connected via the switched capacitor branch to the input end of the primary-stage amplification unit, and the input end of the secondary-stage amplification unit is provided with an independent bias voltage; in a low-gain operating mode, the switched capacitor branch is closed, and at the same time, a secondary amplification unit path connected to the switched capacitor branch is opened. By adopting the technical solutions of capacitor voltage division and nonlinear component cancellation, and when a low-noise amplifier adopts an active amplification structure, the present invention achieves relatively high linearity performance for a low-noise amplifier in a low-gain operating mode.