Receiver AGC Clocked Offset Compensation for Low-Power Linearity
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Solution Overview
Problem
RF receiver circuits face high power consumption due to maintaining linearity and sensitivity, which degrades battery life in mobile applications, and existing AGC designs are sensitive to component offsets and manufacturing variations, affecting gain control accuracy.
Innovation Solution
Incorporating a voltage offset-compensating circuit with a clock generator and capacitors to dynamically adjust the gain of the amplifier, compensating for inherent offset voltages in the AGC components, allowing the use of low-cost components without degrading sensitivity and linearity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If analogue circuits maintain high gain to improve sensitivity to low input power signals, then sensitivity is improved, but power consumption increases and linearity degrades for high input power signals
Solution Approach 1:
The patent implements dynamic gain adjustment through an automatic gain control circuit that continuously monitors input signal power and adjusts the amplifier gain accordingly. The gain is adjusted in discrete steps based on the detected signal level, allowing the system to optimize between sensitivity and power consumption based on real-time conditions
2Measurement precision
If analogue circuits maintain high gain to improve sensitivity to low input power signals, then sensitivity is improved, but linearity degrades for high input power signals
Solution Approach 1:
The automatic gain control circuit dynamically adjusts the amplifier gain based on the detected input signal power level. When high power signals are detected, the gain is reduced to maintain linearity and prevent signal compression. When low power signals are detected, the gain is increased to improve sensitivity. This dynamic adjustment resolves the contradiction between maintaining sensitivity and preserving linearity across different signal conditions
3Device complexity
If conventional AGC circuits use fixed threshold values for gain control, then the circuit is simple to implement, but the AGC becomes sensitive to component offsets and manufacturing variations
Solution Approach 1:
The patent implements an offset compensation circuit that performs preliminary measurement and compensation of comparator offset voltages before the actual AGC operation. By pre-characterizing and compensating for component offsets, the system eliminates the sensitivity to manufacturing variations while maintaining circuit simplicity. This preliminary action ensures robust AGC performance without requiring complex real-time correction mechanisms
Data Source
AI summary
The present invention relates to a receiver circuit for processing of electrical signals, and comprising:an antenna (12),at least one amplifier (14) coupled to the output of the antenna (12),an automatic gain control circuit (30) coupled to the at least one amplifier (14) to modify a gain thereof, andat least one voltage offset-compensating circuit (50) embedded in the automatic gain control circuit (30) and comprising a clock generator (40) and at least one capacitor (42, 44) to effectively compensate an offset voltage.