Mode-Switched Bias Circuit in Power Amplifier Modules
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Power amplifier modules in mobile communication devices face challenges in maintaining high linearity across wide dynamic ranges while minimizing power consumption, particularly in operating modes such as HSUPA, LTE, and LTE-Advanced, where optimal bias circuit configuration is difficult to achieve for multiple operation modes.
Innovation Solution
A power amplifier module with a bias circuit that includes first and second transistors and resistors, where the transistors are turned ON/OFF based on specific bias control voltages to supply suitable bias currents depending on the operation mode, allowing for optimal bias control in multiple operation modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a high power supply voltage is used to maintain high linearity across wide dynamic range, then linearity is improved, but power consumption increases
Solution Approach 1:
The bias circuit dynamically adjusts the bias control voltage based on the operation mode (first or second mode) to optimize the balance between linearity and power consumption. The circuit transitions from a static bias configuration to a dynamic one that adapts to different operating conditions, allowing high linearity when needed while reducing power consumption during normal operation.
Solution Approach 2:
The invention changes the bias control voltage parameter according to the operation mode. By switching between different bias control voltages (first bias control voltage for first mode, second bias control voltage for second mode), the system optimizes performance characteristics for each mode, achieving high linearity in first mode and reduced power consumption in second mode.
2Device complexity
If a single bias circuit configuration is used for multiple operation modes, then device complexity is reduced, but adaptability to different operation modes deteriorates
Solution Approach 1:
The bias circuit is designed with multi-functionality to handle multiple operation modes. By incorporating mode identification capability and switching mechanisms, the same bias circuit structure can adapt to different operation modes (first mode for high linearity, second mode for power efficiency), making the circuit universal across different operating conditions without requiring separate dedicated circuits for each mode.
Data Source
AI summary
A power amplifier module includes an amplifier transistor and a bias circuit. A first power supply voltage based on a first operation mode or a second power supply voltage based on a second operation mode is supplied to the amplifier transistor. The amplifier transistor receives a first signal and outputs a second signal obtained by amplifying the first signal. The bias circuit supplies a bias current to the amplifier transistor. The bias circuit includes first and second resistors and first and second transistors. The first transistor is connected in series with the first resistor and is turned ON by a first bias control voltage which is supplied when the first operation mode is used. The second transistor is connected in series with the second resistor and is turned ON by a second bias control voltage which is supplied when the second operation mode is used.