Polar Phased-Array Transmitter with Digital Predistortion
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Solution Overview
Problem
Existing phased-array transmitters face challenges with low system efficiency, high power consumption, and phase/amplitude errors due to the need for balancing efficiency and linearity, while polar transmitters have limitations in wide frequency band and high scanning resolution requirements.
Innovation Solution
A polar phased-array transmitter architecture is developed, separating amplitude and phase paths and incorporating digital predistortion technology to achieve high scanning resolution and low phase/amplitude errors, suitable for miniaturized devices like mobile terminals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If analog modulation technology with RF phase shift is used in phased-array transmitter, then beam steering and scanning functions are achieved, but system efficiency decreases and power consumption increases
Solution Approach 1:
The patent replaces the traditional analog RF phase shift mechanism with a digital baseband processing system. Instead of using analog phase shifters in the RF path that consume significant power, the invention performs phase shifting through digital signal processing at baseband, thereby achieving beam steering functionality while dramatically reducing power consumption and improving system efficiency.
Solution Approach 2:
The patent changes the operating parameters by moving phase shift control from the RF domain to the baseband domain. This parameter transformation allows the system to achieve the same beam steering effect through digital processing, avoiding the power consumption penalties associated with analog RF phase shifters operating at high frequencies.
2Use of energy by moving object
If analog polar transmitter is used to improve power efficiency, then data rate and channel bandwidth are limited
Solution Approach 1:
The patent replaces the analog polar modulation architecture with a digital baseband processing system. This substitution enables the system to achieve both high power efficiency through digital control and high data rates through advanced digital signal processing techniques, overcoming the fundamental limitation of analog polar transmitters that constrained data rate and channel bandwidth.
3Measurement precision
If digital predistortion is applied to reduce phase and amplitude errors, then manufacturing precision requirements increase
Solution Approach 1:
The patent implements digital predistortion technology that uses feedback mechanisms to measure and compensate for phase and amplitude errors in the RF chain. By characterizing the nonlinearities and applying inverse compensation in the digital domain, the system achieves high phase and amplitude accuracy without requiring extremely tight manufacturing tolerances on individual components.
Solution Approach 2:
The patent applies predistortion processing in advance before the signal enters the nonlinear RF amplification stage. By pre-compensating for expected distortions through digital processing, the system achieves high accuracy output without requiring precise manufacturing of the amplification components, as the correction is applied proactively rather than requiring post-manufacturing calibration.
Data Source
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AI summary
An embodiment of the present invention discloses a polar phased-array transmitter and a mobile terminal. The mobile terminal includes: a baseband chip, the polar phased-array transmitter, and an antenna array. The baseband chip is configured to generate a quadrature digital baseband signal; the polar phased-array transmitter is configured to: perform quadrature-to-polar processing on the quadrature digital baseband signal to generate n amplitude signals and n phase signals, separately perform phase modulation and phase shifting on the n phase signals by using a local oscillator signal to obtain n phase modulation signals, and perform amplitude modulation and power amplification on the n phase modulation signals by using the amplitude signals to obtain n radio frequency signals, where n is a natural number greater than 1; and the antenna array is configured to: obtain the n radio frequency signals from the polar phased-array transmitter, and transmit the n radio frequency signals.