Coupled Transmission-Line Doherty Amplifier for Wider Bandwidth
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Solution Overview
Problem
The bandwidth limitation of Doherty power amplifiers restricts their efficiency and power consumption reduction across a wide range of operating frequencies, particularly in modern wireless communication systems.
Innovation Solution
A Doherty power amplifier design featuring mutually coupled open-circuited transmission lines and an impedance transformation and phase compensation network, allowing for electric and magnetic coupling to achieve a second harmonic short-circuit over both low power and Doherty regions, thereby enhancing bandwidth and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional Doherty power amplifier configuration is used, then efficiency at back-off is improved, but bandwidth is limited
Solution Approach 1:
The patent combines electric coupling and magnetic coupling mechanisms in the load modulation network to simultaneously achieve broad bandwidth and high efficiency at back-off. The coupled transmission lines merge multiple coupling effects to resolve the traditional trade-off between bandwidth and efficiency.
Solution Approach 2:
The patent changes the coupling parameters of the transmission lines by adjusting their physical arrangement and electrical characteristics to achieve both wide bandwidth operation and maintained efficiency across the frequency range, resolving the contradiction between these two parameters.
2Adaptability or versatility
If bandwidth is increased, then adaptability is improved, but efficiency at back-off may deteriorate
Solution Approach 1:
The patent merges electric and magnetic coupling mechanisms in the load modulation network to simultaneously achieve broad bandwidth and high efficiency at back-off. The coupled transmission lines merge multiple coupling effects to resolve the traditional trade-off between bandwidth and efficiency.
Solution Approach 2:
The patent changes the coupling parameters of the transmission lines by adjusting their physical arrangement and electrical characteristics to achieve both wide bandwidth operation and maintained efficiency across the frequency range, resolving the contradiction between these two parameters.
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
The design achieves a broad bandwidth and improved efficiency across the operating frequency range, reducing power consumption and maintaining high efficiency from back-off to saturation points, suitable for battery-powered devices and high-power applications.
Implementation Method 1
the mutual coupling comprises an electric coupling
Implementation Method 2
the mutual coupling comprises or further comprises a magnetic coupling
Data Source
AI summary
A Doherty power amplifier includes a main device in a main amplifier circuit and an auxiliary device in an auxiliary amplifier circuit arranged in parallel with the main amplifier circuit. The Doherty power amplifier further includes a load modulation network including a first open-circuited transmission line connected to an output of the main device; a second open-circuited transmission line connected to an output of the auxiliary device; and an impedance transformation and phase compensation network connected with the output of the main device and the output of the auxiliary device for providing a combined output power. The first and second open-circuited transmission lines are arranged directly adjacent one another to form, during operation, a mutual coupling therebetween.