Outphasing Amplifier Compensation for Linearity and Branch Balance
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Solution Overview
Problem
Existing outphasing amplification apparatuses face challenges with large circuit sizes and significant calculation loads due to the need for complex non-linearity compensation and inter-branch amplitude imbalance correction, which affects the dynamic range and linearity of the output signal.
Innovation Solution
The proposed solution includes a signal separation unit for phase modulation, a non-linearity compensation unit, and deviation compensation units that calculate and apply non-linearity and deviation compensation coefficients to the input baseband signal, reducing the circuit complexity and calculation load by using lookup tables for efficient coefficient calculation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If complex non-linearity compensation and inter-branch amplitude imbalance correction are implemented, then linearity and dynamic range are improved, but circuit size and calculation load increase
Solution Approach 1:
The patent pre-calculates and stores compensation coefficients in lookup tables before operation. The non-linearity compensation coefficient calculation unit and inter-branch amplitude imbalance compensation coefficient calculation unit compute these coefficients in advance based on system characteristics, then store them in memory structures. During actual operation, the system simply retrieves and applies these pre-computed coefficients, avoiding real-time complex calculations and reducing circuit complexity while maintaining linearity performance.
Solution Approach 2:
The patent replaces complex real-time computational mechanisms with lookup table-based retrieval systems. Instead of performing complex non-linearity compensation calculations in real-time through sophisticated circuitry, the system substitutes these mechanical/computational processes with pre-computed coefficient tables that can be quickly accessed and applied, significantly reducing the calculation load and circuit size required.
2Manufacturing precision
If complex non-linearity compensation and inter-branch amplitude imbalance correction are implemented, then linearity and dynamic range are improved, but calculation load increases
Solution Approach 1:
The patent pre-calculates and stores compensation coefficients in lookup tables before operation. The non-linearity compensation coefficient calculation unit and inter-branch amplitude imbalance compensation coefficient calculation unit compute these coefficients in advance based on system characteristics, then store them in memory structures. During actual operation, the system simply retrieves and applies these pre-computed coefficients, avoiding real-time complex calculations and reducing circuit complexity while maintaining linearity performance.
Solution Approach 2:
The patent replaces complex real-time computational mechanisms with lookup table-based retrieval systems. Instead of performing complex non-linearity compensation calculations in real-time through sophisticated circuitry, the system substitutes these mechanical/computational processes with pre-computed coefficient tables that can be quickly accessed and applied, significantly reducing the calculation load and circuit size required.
3Loss of energy
If Chireix combiner is used to reduce combining loss, then efficiency is improved, but inter-branch amplitude imbalance occurs
Solution Approach 1:
The patent implements feedback mechanisms to measure and compensate for inter-branch amplitude imbalance. The system includes a feedback path that monitors the output signals from the Chireix combiner and feeds this information back to the coefficient calculation units. Based on this feedback, the non-linearity compensation coefficient calculation unit and inter-branch amplitude imbalance compensation coefficient calculation unit adjust the compensation coefficients to correct amplitude imbalance, thereby maintaining both efficiency and amplitude balance.
Solution Approach 2:
The patent dynamically adjusts compensation parameters to correct inter-branch amplitude imbalance. By changing the compensation coefficients stored in the lookup tables based on operating conditions and measured imbalance, the system adapts to maintain amplitude balance while preserving the efficiency benefits of the Chireix combiner architecture.
Data Source
AI summary
In an amplification apparatus according to the present disclosure, a combining unit combines an output signal of a first amplifier provided at a first branch with an output signal of a second amplifier provided at a second branch and outputs the combined signal. A non-linearity compensation unit multiplies an input baseband signal by a non-linearity compensation coefficient for compensating non-linearity of the entire apparatus, a first deviation compensation unit multiplies a first branch signal by a first deviation compensation coefficient for compensating an inter-branch deviation, and a second deviation compensation unit multiplies a second branch signal by a second deviation compensation coefficient for compensating the inter-branch deviation. A compensation coefficient calculation unit calculates the non-linearity compensation coefficient, the first deviation compensation coefficient, and the second deviation compensation coefficient based on the input baseband signal and a feedback baseband signal obtained by feeding back the combined signal.