Lookup-Table Transmitter Control for Linear Power Amplification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Transmitter circuits, particularly power amplifiers, face challenges in achieving optimal power efficiency and linearity, leading to distortion in amplified communications signals, which affects the quality of wireless transmission.
Innovation Solution
An apparatus is introduced that includes an analog circuit with a lookup table to generate a control signal based on the communications signal or its metrics, which is used to optimize the amplification process, thereby improving signal linearity and reducing distortion. This apparatus can be coupled with various analog circuits such as amplifiers, mixers, and filters, and includes signal conditioning circuits to ensure proper timing and frequency management of the control signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If power amplifiers are designed to increase power efficiency, then energy consumption is reduced, but signal linearity deteriorates causing amplitude-dependent distortion
Solution Approach 1:
The invention segments the amplification process into multiple stages with different operating modes. A switchable amplifier architecture divides the signal range into multiple segments, with each segment handled by a dedicated amplifier optimized for specific operating conditions. This segmentation allows the system to maintain high power efficiency in certain segments while preserving signal linearity in others, resolving the contradiction between power efficiency and signal linearity.
Solution Approach 2:
The invention employs dynamic switching between different amplifier configurations and operating modes based on real-time signal conditions. The system dynamically adjusts which amplifier is active and how they are connected, allowing optimal power efficiency at low power levels and optimal linearity at high power levels. This dynamic adaptation resolves the static contradiction between power efficiency and signal linearity across different operating points.
2Manufacturing precision
If power amplifiers are designed to improve linearity, then signal distortion is reduced, but power efficiency deteriorates
Solution Approach 1:
The amplifier system is segmented into multiple parallel amplifier paths, each optimized for specific operating conditions. One path is optimized for high linearity while another is optimized for high efficiency. The system segments the signal processing based on operating point requirements, directing signals through the appropriate amplifier path to achieve optimal performance for each condition without compromising overall power efficiency.
Solution Approach 2:
The invention changes operating parameters dynamically by switching between different amplifier configurations. When high linearity is required, the system adjusts bias conditions and amplifier connections to prioritize linearity. When power efficiency is paramount, it reconfigures the amplifier operating points to maximize efficiency. This parameter changes approach allows the system to optimize linearity without permanently sacrificing power efficiency.
3Power
If analog circuits operate at high power levels, then transmission power is increased, but signal distortion increases due to non-linear operation
Solution Approach 1:
The high power amplification is segmented into multiple amplifier stages rather than using a single high-power amplifier. Each stage operates at moderate power levels where linear operation is easier to maintain. The segmented architecture with switches connects these stages in different configurations, allowing the system to achieve high overall transmission power while each individual stage operates in a more linear region, thereby reducing signal distortion.
Solution Approach 2:
The invention introduces switching circuits and control logic as intermediary elements between the signal source and the amplifiers. These intermediaries dynamically reconfigure the amplifier connections based on signal power levels and distortion characteristics. When distortion is detected or anticipated at high power levels, the intermediary switching mechanism redirects the signal through alternative paths or adjusts operating conditions to minimize distortion while maintaining high transmission power.
Data Source
AI summary
An apparatus for transmitter control is disclosed. The apparatus includes an analog circuit designed to operate on at least a portion of a communications signal to be wirelessly transmitted, based at least in part on a control signal. The apparatus includes a lookup table coupled to the analog circuit, with the lookup table designed to output the control signal based at least in part on the communications signal, or one or more measured metrics of the communications signal. Embodiments of the present invention include, but are not limited to, methods encompassing the operations described above, as well as subsystems and systems designed to operate in the above described manner.