Ultra-Wideband Power Amplifier With Traveling-Wave Linearity
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Solution Overview
Problem
Ultra-wideband power amplifiers face challenges in achieving both high efficiency and high linearity, particularly under low power backoff conditions, due to the adverse effects of linearization techniques and the unsuitability of narrow-band linearization methods for multi-octave bands.
Innovation Solution
The design incorporates a preamplifier circuit and a post amplifier circuit, utilizing a single transistor matched with a traveling wave structure, and a multi-stage traveling wave structure in the post amplifier circuit to achieve high linearity and efficiency under low power backoff.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If linearization techniques (load modulation, pre-distortion) are applied to improve linearity, then linearity is improved, but device complexity increases and amplification effect deteriorates
Solution Approach 1:
The patent extracts and eliminates the complex linearization techniques (load modulation, pre-distortion) from the system, achieving linearity improvement through a simpler traveling wave structure that inherently provides linear amplification without requiring additional complex circuitry
Solution Approach 2:
The patent replaces complex linearization mechanisms with a simpler, more direct traveling wave amplifier structure that achieves comparable or superior linearity performance without the overhead of complex control and modulation circuits
2Measurement precision
If narrow-band linearization techniques (Doherty, harmonic termination, harmonic injection) are used to improve linearity, then linearity is improved, but adaptability to ultra-wideband multi-octave applications deteriorates
Solution Approach 1:
The traveling wave amplifier structure serves multiple functions simultaneously: it provides linear amplification across ultra-wideband frequencies, maintains high efficiency, and adapts to multi-octave applications without requiring separate linearization circuits for each frequency band, making it universally applicable
Solution Approach 2:
The patent employs dynamic traveling wave structures that can adapt to different frequency ranges within the ultra-wideband spectrum, allowing the amplifier to maintain optimal performance across multiple octaves rather than being fixed to a narrow frequency band
3Measurement precision
If power backoff method is applied to improve linearity, then linearity is improved, but amplification efficiency deteriorates
Solution Approach 1:
The patent changes the fundamental operating parameters of the amplifier by using traveling wave structures that maintain optimal efficiency across a wide range of output power levels, eliminating the need to operate at reduced power levels (backoff) to achieve linearity, thus maintaining high efficiency while improving linearity
Data Source
AI summary
An ultra-wideband power amplifier includes a preamplifier circuit and a post amplifier circuit. The preamplifier circuit includes a first DC blocking capacitor C1, a first decoupling capacitor C2, a second decoupling capacitor C3, a stabilizing resistor Rin, a first AC blocking resistor RG1, a first input inductor L1, a second input inductor L2, an output inductor L3, a first input microstrip line MLIN1, a second input microstrip line MLIN2, an output microstrip line MLIN3, and a first transistor Q1. A first end of the first DC blocking capacitor C1 acts as an input terminal of the preamplifier circuit, and a second end of the first DC blocking capacitor C1 is connected to the stabilizing resistor Rin, the first input inductor L1, the first input microstrip line MLIN1, and a gate electrode of the first transistor Q1 sequentially. One end of the first decoupling capacitor C2 is grounded.