Broadband RF Linear Amplifier With Multi-Band Gain and Phase Control
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Solution Overview
Problem
Conventional RF power amplifiers struggle to provide high linearity across multiple non-overlapping RF frequency bands, leading to increased complexity and cost in wireless devices, as they typically require multiple amplifiers to operate effectively, which complicates miniaturization and power consumption.
Innovation Solution
A broad-band linear amplifier circuit that includes a driver amplifier, power amplifier, sensing circuit, biasing circuit, and gain control circuit, along with a multi-band filter, allowing for linear amplification across multiple non-overlapping RF bands by selectively activating narrow-band filters and optimizing gain and phase control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple power amplifiers are used to cover multiple non-overlapping RF bands, then the frequency coverage is improved, but the device complexity and cost increase
Solution Approach 1:
The patent implements a single power amplifier capable of operating across multiple non-overlapping RF bands by incorporating a broadband matching network. This network includes multiple impedance transformation paths that can be selectively activated through switching mechanisms, allowing one amplifier to perform the function of multiple amplifiers would otherwise be needed for different frequency bands
2Adaptability or versatility
If multiple power amplifiers are used to cover multiple non-overlapping RF bands, then the frequency coverage is improved, but the device size increases
Solution Approach 1:
The patent merges multiple impedance matching networks into a single integrated broadband matching network structure. This network combines multiple L-section or Pi-section matching circuits that can be selectively activated through switching mechanisms, allowing one amplifier to serve multiple frequency bands without requiring separate amplifier circuits for each band
3Reliability
If conventional power amplifiers are designed for a single RF band, then the amplification linearity is maintained, but the bandwidth is limited
Solution Approach 1:
The patent employs dynamic impedance matching through switching mechanisms that can reconfigure the matching network according to the operating frequency band. The broadband matching network includes multiple impedance transformation paths with different characteristic impedances that are selectively activated to maintain optimal matching and linearity across different frequency bands
Solution Approach 2:
The patent changes the impedance parameters of the matching network dynamically by switching between different L-section or Pi-section matching circuits. Each section is designed with specific impedance values optimized for particular frequency ranges, allowing the system to maintain amplification linearity while adapting to different bandwidth requirements
Data Source
AI summary
A broad-band linear amplifier circuit includes a driver amplifier to produce a first amplified radio frequency (RF) signal in a first single RF band in response to a first input RF signal and to produce a second amplified RF signal in a second single RF band in response to a second input RF signal. The first single RF band and the second single RF band reside in a broad band that has a bandwidth more than two times a bandwidth of the first single RF band or the second single RF band. A sensing circuit can sense a power, a gain, or a phase of the first output RF signal and the second output RF signal, and to produce a sensing signal. A gain control circuit controls gain variation of the driver amplifier in response to the sensing signal.