Transmission Circuit Pre-Equalization for Spectrum Regrowth Control
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Solution Overview
Problem
Existing transmission circuits suffer from amplitude-amplitude (AM-AM) and amplitude-phase (AM-PM) errors due to interactions between the power amplifier circuit and the RF front-end circuit, leading to undesired amplitude distortion and spectrum regrowth, especially in wide modulation bandwidths.
Innovation Solution
The transceiver circuit is configured to equalize the input vector using multiple complex filters, applying a frequency equalization filter to correct AM-AM and AM-PM errors, thereby reducing instantaneous excessive compression and spectrum regrowth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the power amplifier circuit is coupled to the RF front-end circuit to amplify RF signals, then the RF signal power is increased, but AM-AM and AM-PM errors are introduced causing amplitude distortion and spectrum regrowth
Solution Approach 1:
The patent applies preliminary action by pre-compensating the input signal to the power amplifier circuit. The transceiver circuit modifies the input signal characteristics before amplification to counteract the expected AM-AM and AM-PM errors that will occur during amplification. This predictive correction approach allows the system to maintain amplitude accuracy while still achieving the required power amplification, resolving the contradiction between power output and amplitude precision.
2Productivity
If the modulation bandwidth is increased to provide higher data rates, then the communication capacity is improved, but the AM-AM and AM-PM errors become more significant causing greater amplitude distortion
Solution Approach 1:
The patent applies local quality by implementing frequency-dependent correction parameters tailored to different portions of the modulation bandwidth. Rather than using a single correction approach for the entire bandwidth, the system adjusts the pre-compensation characteristics based on the specific frequency components present. This allows optimal correction accuracy to be maintained across the wide modulation bandwidth, enabling high data rates without sacrificing amplitude precision.
3Use of energy by moving object
If the power amplifier operates at higher efficiency, then energy consumption is reduced, but instantaneous excessive compression occurs leading to signal distortion
Solution Approach 1:
The patent applies dynamics by implementing adaptive pre-compensation that dynamically adjusts to the instantaneous operating conditions of the power amplifier. The system continuously monitors and adjusts the input signal characteristics based on the current operating point, allowing the power amplifier to operate efficiently across varying signal conditions without entering the compression region. This dynamic adaptation maintains signal linearity while maximizing power amplifier efficiency under different load and signal conditions.
Data Source
AI summary
Phase and amplitude error correction in a transmission circuit is provided. The transmission circuit includes a transceiver circuit, a power management integrated circuit (PMIC), and a power amplifier circuit(s). The transceiver circuit generates a radio frequency (RF) signal(s) from an input vector, the PMIC generates a modulated voltage, and the power amplifier circuit(s) amplifies the RF signal(s) based on the modulated voltage. In embodiments disclosed herein, the transceiver circuit is configured to equalize the input vector using multiple complex filters to thereby correct amplitude-amplitude (AM-AM) and amplitude-phase (AM-PM) errors. As a result, it is possible to reduce undesired instantaneous excessive compression and/or spectrum regrowth to thereby improve efficiency and linearity of the power amplifier circuit(s) across the modulation bandwidth.