Envelope-Tracking RF Power Amplifier for Broadband Multi-Band Efficiency
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Solution Overview
Problem
Existing power amplifiers for mobile devices and base stations require multiple separate units to support various frequency bands, leading to increased size, cost, and complexity, and have limited bandwidth and efficiency, particularly in modern communication standards that demand broader frequency ranges.
Innovation Solution
A power amplifier design featuring an envelope tracking power supply, carrier amplifier, input matching network, peak amplifier, impedance transformer, and output matching network, which splits and combines signals to optimize power usage and impedance transformation based on input power levels, allowing for flexible phase shifting and reduced complexity through serial connection of amplifiers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple separated low voltage and impedance PAs are used to support multiple frequency bands, then frequency band coverage is improved, but device size, cost, and complexity increase
Solution Approach 1:
The patent implements a universal PA design that can operate across multiple frequency bands (e.g., 700MHz to 2600MHz) by using broadband matching networks and adjustable impedance transformation ratios. A single PA circuit is configured to handle different frequency bands through reconfigurable impedance matching, eliminating the need for multiple dedicated PAs for different bands while maintaining full frequency band coverage capability
Solution Approach 2:
The patent employs dynamic impedance adjustment mechanisms including variable impedance transformation ratios and reconfigurable matching networks that can adapt to different operating frequency bands in real-time. This dynamic configuration allows a single PA to optimize its performance for each frequency band without requiring separate static PAs for each band
2Adaptability or versatility
If multiple separated low voltage and impedance PAs are used to support multiple frequency bands, then frequency band coverage is improved, but device size increases
Solution Approach 1:
The patent merges multiple PA functions into a single integrated PA circuit that can handle multiple frequency bands. By combining the amplification function with reconfigurable impedance matching networks, the design consolidates what would traditionally require multiple separate PA units into one compact component, significantly reducing the space required in mobile devices
Solution Approach 2:
A single universal PA is designed to perform the function of multiple band-specific PAs through broadband operation and reconfigurable impedance matching. This multi-functional approach allows one PA to replace several PAs, directly reducing the overall device volume while maintaining support for all required frequency bands
3Device complexity
If traditional fixed power supply is used, then circuit simplicity is maintained, but power amplification efficiency deteriorates
Solution Approach 1:
The patent implements an envelope tracking power supply system that dynamically adjusts the DC supply voltage to match the instantaneous envelope of the RF signal. This dynamic voltage adjustment ensures the PA operates at optimal efficiency across varying signal conditions, maintaining high efficiency during both peak and average power operations while using programmable control logic rather than complex analog circuits
4Device complexity
If carrier amplifier alone is used, then circuit simplicity is maintained, but bandwidth and efficiency are limited
Solution Approach 1:
The patent segments the amplification function into two distinct paths: a carrier amplifier path for continuous signal amplification and a peak amplifier path for high-power signal enhancement. This segmentation allows each amplifier to be optimized for its specific function while working together to achieve broader bandwidth and higher efficiency across the entire operating range
Data Source
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AI summary
Power amplifiers for amplifying a radio frequency signal are provided. The power amplifier may include an envelope tracking power supply, a carrier amplifier coupled with the power supply and configured to amplify the radio frequency signal, an input matching network configured to split the amplified radio frequency signal from the carrier amplifier such that one part of the amplified radio frequency signal passes along a peak amplifier path and another part of the amplified radio frequency signal passes along an impedance transformer path, a peak amplifier coupled with the power supply and configured to amplify the one part of the amplified radio frequency signal from the input matching network, an impedance transformer configured to perform impedance transformation on the other part of the amplified radio frequency signal from the input matching network, an output matching network configured to combine the output of the peak amplifier and the impedance transformer.