RF Power Amplifier Bias and Voltage Control at Low Output Power
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Solution Overview
Problem
Current wireless communication apparatuses face challenges in reducing power consumption, particularly at low power levels, as existing techniques like envelope tracking mode are not effective and result in inefficient power usage due to fixed source voltage settings, leading to increased power loss and reduced battery life in mobile devices.
Innovation Solution
A wireless communication apparatus with a power amplifying circuit, source voltage generating circuit, and bias control circuit that switches between envelope tracking, variable control, and fixed control modes based on output power levels, adjusting source voltage and bias in proportion to power levels to optimize power efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If envelope tracking mode is used with fixed source voltage, then power amplification is achieved, but power consumption increases and power added efficiency decreases at low power levels
Solution Approach 1:
The patent applies dynamics by switching between fixed source voltage mode and variable source voltage mode based on the operating state of the power amplifier. When the power amplifier operates at low power levels, the system transitions to variable source voltage mode where the source voltage dynamically tracks the envelope of the modulated signal, thereby optimizing power consumption and improving power added efficiency at low power levels while maintaining power amplification capability.
Solution Approach 2:
The patent changes the source voltage parameter from a fixed value to a variable value that tracks the signal envelope. By monitoring the power level and switching between fixed and variable source voltage modes, the system optimizes the power consumption and power added efficiency parameters, particularly improving performance at low power levels where traditional fixed voltage modes are inefficient.
2Ease of operation
If fixed source voltage is used in power amplifying circuit, then circuit operation is simplified, but power added efficiency decreases at low power levels
Solution Approach 1:
The system dynamically adjusts the source voltage based on the operating power level. At low power levels, it switches to variable source voltage mode where the voltage tracks the signal envelope, thereby improving power added efficiency. This dynamic approach maintains ease of operation through automated mode switching while reducing energy loss at low power levels.
Solution Approach 2:
The patent changes the source voltage parameter from fixed to variable by introducing envelope tracking. The control circuit monitors the power level and adjusts the source voltage accordingly, changing the electrical parameter to optimize power added efficiency at low power levels while maintaining simplified circuit operation through automated control.
3Loss of energy
If envelope tracking mode is implemented, then power added efficiency is improved at low power levels, but device complexity increases due to additional circuits
Solution Approach 1:
The patent segments the operating modes into distinct fixed source voltage mode and variable source voltage mode. The control circuit segments the power levels and selects the appropriate mode based on the current operating state. This segmentation allows the system to implement envelope tracking only when needed (at low power levels), improving power added efficiency while limiting the increase in device complexity to specific operational segments.
Solution Approach 2:
The system dynamically switches between fixed and variable source voltage modes based on power level conditions. This dynamic mode switching enables the system to implement envelope tracking selectively only when it provides benefit (at low power levels), thereby improving power added efficiency while avoiding the continuous complexity overhead of full envelope tracking implementation across all operating conditions.
4Use of energy by moving object
If variable source voltage control is used, then power consumption is reduced, but control circuit complexity increases
Solution Approach 1:
The control circuit is segmented into mode detection functionality and voltage control functionality. The system detects the power level segment and selects the appropriate control mode (fixed or variable source voltage). This segmentation simplifies the control circuit by implementing variable source voltage control only in the necessary operational segment (low power levels), reducing overall power consumption while limiting control circuit complexity to manageable levels.
Solution Approach 2:
The control circuit changes the source voltage parameter based on detected power levels. By implementing parameter changes only when beneficial (at low power levels), the system reduces power consumption while avoiding the continuous complexity overhead of full variable control implementation. The control circuit monitors power level and adjusts the voltage parameter selectively.
Data Source
AI summary
A high-frequency signal processing apparatus and a wireless communication apparatus can achieve a decrease in power consumption. For example, when an indicated power level to a high-frequency power amplifier is equal to or greater than a second reference value, envelope tracking is performed by causing a source voltage control circuit to control a high-speed DCDC converter using a detection result of an envelope detecting circuit and causing a bias control circuit to indicate a fixed bias value. The source voltage control circuit and the bias control circuit indicate a source voltage and a bias value decreasing in proportion to a decrease in the indicated power level when the indicated power level is in a range of the second reference value to the first reference value, and indicate a fixed source voltage and a fixed bias value when the indicated power level is less than the first reference value.