Class-E Power Amplifier Bias Circuit Without Charge Pumps
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Solution Overview
Problem
Highly efficient microwave and RF amplifiers face challenges in generating high bias voltages required for cascode configurations, leading to interference and increased power consumption when using charge pumps, which results in lower efficiency.
Innovation Solution
A biasing method that involves tapping the amplifier output to generate an AC voltage, rectifying it, and dividing it to produce bias voltages for MOSFET devices in a class-E power amplifier, using a combination of AC and DC voltage dividers and rectifiers to provide stable biasing without the need for charge pumps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If charge pumps are used to generate high bias voltages, then the required bias voltages can be obtained, but interference occurs and power consumption increases
Solution Approach 1:
The amplifier output signal itself is used to generate the bias voltages through rectification and voltage division. The system serves itself by converting its own output into the required bias signals, eliminating the need for external charge pumps and their associated interference and power consumption issues
Solution Approach 2:
The mechanical/electrical charge pump system is replaced with a passive rectifier and voltage divider network. This substitution eliminates the active switching components that cause interference, using instead a simpler passive circuit topology that rectifies the amplifier output to generate the necessary bias voltages
2Power
If charge pumps are used to generate bias voltages, then high voltages can be provided, but circuit complexity increases
Solution Approach 1:
The complex active charge pump circuit is replaced with a simple passive rectifier and voltage divider network. This substitution maintains the ability to generate high bias voltages while dramatically reducing circuit complexity by using only passive components
Solution Approach 2:
The amplifier output signal serves multiple functions: it is both the amplified output signal and the source for generating bias voltages for the amplifier stages. This multi-functionality eliminates the need for separate bias generation circuits, reducing overall system complexity
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
This approach reduces power consumption and interference, achieving higher efficiency and dynamic range for power amplifiers by generating bias voltages efficiently without the complexity and power consumption associated with charge pumps.
Implementation Method 1
a rectifier, the rectifier having a rectifier DC voltage output and rectifying an AC voltage originated from the power amplifier AC output voltage to a DC voltage
Implementation Method 2
dividing the rectified voltage to produce one or more bias voltages
Data Source
AI summary
Biasing methods and devices for power amplifiers are described. The described methods and devices use the power amplifier output voltage to generate bias voltages. The bias voltages are obtained using rectifiers and voltage dividers. The described biasing methods and devices can be used with class-E power amplifiers.