Magnetically Coupled Doherty Amplifier for 400 MHz Modulation Bandwidth
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Solution Overview
Problem
Traditional Doherty amplifiers have limited modulation bandwidth, which is insufficient to meet the 400 MHz modulation requirements of 5G-NR applications.
Innovation Solution
A Doherty amplifier system is designed with a carrier amplifier and a peaking amplifier, utilizing inductors to form magnetic couplings that create impedance inverters, along with supply voltage modulation and input power scaling circuitry to enhance power efficiency and bandwidth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If traditional Doherty amplifier architecture is used, then power efficiency is improved, but modulation bandwidth is limited and insufficient for 5G-NR applications
Solution Approach 1:
The amplifier is divided into multiple parallel paths: a main Doherty path (with carrier and peaking amplifiers) and an auxiliary path (with separate amplifier). This segmentation allows each path to handle different signal components, enabling the system to achieve both high efficiency at average power levels and extended bandwidth for 5G-NR modulation requirements through coordinated operation of the segmented paths
Solution Approach 2:
The patent extends the traditional two-dimensional Doherty architecture (carrier and peaking amplifiers) into a three-dimensional configuration by adding an auxiliary amplifier path. This dimensional expansion provides additional degrees of freedom for impedance control and signal handling, enabling simultaneous achievement of high efficiency and wide 400 MHz modulation bandwidth required for 5G-NR
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 system achieves improved power efficiency and increased modulation bandwidth, effectively addressing the limitations of traditional Doherty amplifiers for 5G-NR applications.
Implementation Method 1
The first inductor and the second inductor are configured to have a first magnetic coupling to form a first impedance inverter
Implementation Method 2
The third inductor and the fourth inductor are configured to have a second magnetic coupling to form a second impedance inverter
Data Source
AI summary
A Doherty amplifier system is disclosed with a carrier amplifier configured to amplify a first portion of a radio frequency (RF) signal. A peaking amplifier with a peaking output is configured to amplify a second portion of the RF signal when it is above a power level threshold. A first inductor is coupled between the main output and a first middle node, and a second inductor is coupled between the first middle node and the peaking output. The first inductor and the second inductor are configured to have a first magnetic coupling to form a first impedance inverter. A third inductor is coupled between the peaking output and a second middle node, and a fourth inductor is coupled between the second middle node and an RF signal output. The third inductor and the fourth inductor are configured to have a second magnetic coupling to form a second impedance inverter.