Wideband Envelope Tracking Circuit for PA Linearity and Power Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current power amplifier systems face challenges in managing power consumption and linearity, especially in mobile devices that require wideband operation and carrier aggregation, which can lead to poor performance and increased cost due to the use of III-V semiconductor processing.
Innovation Solution
The implementation of an envelope tracking system using a DC-to-DC converter, current digital-to-analog converters, error amplifiers, and AC combiners to generate dynamic power amplifier supply voltages based on digital envelope signals, improving power efficiency and linearity by aligning voltage changes with the RF signal envelope.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If envelope tracking is used to reduce power consumption, then power efficiency improves, but bandwidth tracking capability deteriorates
Solution Approach 1:
The patent divides the envelope tracking system into multiple parallel tracking channels, each with its own error amplifier and feedback loop. This segmentation allows simultaneous tracking of multiple frequency components (e.g., 700 MHz and 2.6 GHz) without compromising the bandwidth response of individual channels, thereby resolving the contradiction between power efficiency and bandwidth tracking capability.
Solution Approach 2:
The patent extends the envelope tracking system from a single-dimensional approach to a multi-dimensional architecture by adding parallel processing paths for different frequency bands. This dimensional expansion enables the system to maintain high tracking speed across multiple frequency dimensions while still achieving power consumption reduction through selective amplification.
2Reliability
If III-V semiconductor processing is used for wideband operation, then frequency response improves, but manufacturing cost increases
Solution Approach 1:
The patent changes the operating parameters of the power amplifier by implementing dynamic supply voltage modulation through envelope tracking. This allows the amplifier to operate efficiently across wide frequency bands (700 MHz to 2.6 GHz) without requiring expensive III-V semiconductor materials, as the frequency response is improved through control architecture rather than material properties.
Solution Approach 2:
The patent uses digital envelope signals as copies of the RF signal characteristics to control the power amplifier supply voltage. This digital copying approach enables precise frequency response control through software-defined parameters rather than expensive hardware modifications, allowing wideband operation with cost-effective CMOS processing.
3Use of energy by moving object
If dynamic supply voltage modulation is implemented, then power efficiency improves, but system complexity increases
Solution Approach 1:
The patent implements a universal error amplifier design that can handle multiple frequency bands and modulation schemes through a single standardized circuit architecture. This multi-functional approach reduces overall system complexity compared to having separate dedicated circuits for each frequency band, while still achieving significant power efficiency improvements through dynamic voltage modulation.
Solution Approach 2:
The patent employs feedback mechanisms where error amplifiers continuously monitor and adjust the supply voltage based on the difference between desired and actual envelope levels. This closed-loop feedback simplifies the control logic by automatically compensating for disturbances, reducing the need for complex open-loop control algorithms while maintaining high power efficiency.
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 enhances power amplifier performance by reducing power consumption, improving linearity, and allowing the use of cost-effective CMOS processing technologies, while maintaining high data rates and efficient bandwidth utilization.
Implementation Method 1
generating a regulated voltage from a battery voltage using a DC-to-DC converter
Implementation Method 2
the first error amplifier electrically connected with negative feedback
Data Source
AI summary
Apparatus and methods for wideband envelope tracking systems are disclosed herein. In certain implementations, an envelope tracker includes a DC-to-DC converter, a current digital-to-analog converter (DAC), an error amplifier, a feedback circuit, and an AC combiner. The current DAC receives a digital envelope signal, and uses the digital envelope signal to generate an envelope current. The feedback circuit is connected between an output and an inverting input of the error amplifier, and the envelope current is provided to the error amplifier's inverting input. Additionally, the AC combiner generates a power amplifier supply voltage by combining an output of the DC-to-DC converter and an output of the error amplifier.