RF Amplifier Power Detection Without Coupler Insertion Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing amplification devices suffer from increased insertion loss and reduced linearity due to the use of couplers and log power detectors, which deteriorate signal quality and make it difficult to accurately measure input signal power.
Innovation Solution
An amplification device with a cascade or parallel structure log power detector and an impedance unit that adjusts impedance, combined with temperature compensation mechanisms, to improve linearity and reduce loading effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a coupler is coupled to power amplifiers to detect signal power, then signal power can be measured, but insertion loss increases and signal quality deteriorates
Solution Approach 1:
The patent extracts the detection function from the main signal path by using a separate detected terminal connected to the amplification unit. This allows power measurement without inserting a coupler into the signal path, thereby eliminating insertion loss while maintaining measurement capability.
2Measurement precision
If a log power detector is directly coupled to power amplifiers to measure input signal power, then power measurement is enabled, but loading effect worsens linearity between input and output signals
Solution Approach 1:
The patent introduces an impedance matching network as an intermediary between the amplification unit and the log power detector. This network transforms the impedance to minimize loading effects on the amplification unit, thereby maintaining signal linearity while enabling accurate power measurement through the detector.
3Measurement precision
If log power detector is used to detect signal power, then power indication can be obtained, but loading effect makes it difficult to accurately measure input signal power
Solution Approach 1:
The patent changes the impedance parameter of the detection circuit through the impedance matching network. By transforming the impedance to match the optimal value for the amplification unit, the loading effect is minimized, allowing the log power detector to accurately indicate input signal power without being affected by its own loading.
Data Source
AI summary
An amplification device includes an amplification unit, an impedance unit and a log power detector. The amplification unit includes an input terminal for receiving a radio-frequency signal, an output terminal for outputting an amplified radio-frequency signal, and a detected terminal for outputting a detected signal related to the radio-frequency signal. The impedance unit is used to provide an impedance. The impedance unit includes an input terminal coupled to the detected terminal of the amplification unit for receiving the detected signal, and an output terminal for outputting a power signal. The log power detector is used to generate a power indication signal according to the power signal. The log power detector includes an input terminal coupled to the output terminal of the impedance unit, and an output terminal for outputting the power indication signal.