Switched-Sample Mixing Module for Spur-Aware Radio Reception
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Solution Overview
Problem
Radio receivers face challenges in minimizing noise, particularly due to periodic switching events and circuit imbalances, which introduce undesirable spurs and harmonics, degrading signal quality.
Innovation Solution
The solution involves choosing harmonics of switching rates to avoid the frequency band of the desired received signal and correcting circuit imbalances by implementing alternating functions in circuit elements, using specific filtering and downsampling techniques to minimize noise and spurs, such as employing finite impulse response (FIR) and infinite impulse response (IIR) filters, and adjusting decimation periods relative to mixing periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If digital circuit designs are used to reduce analog noise, then thermal noise is reduced, but periodic switching events introduce undesirable spurs
Solution Approach 1:
The patent applies periodic action by using periodic switching events in the digital circuit design. The switching occurs at specific intervals to perform digital signal processing functions while managing the introduction of spurs through controlled periodic operation of the circuit elements.
Solution Approach 2:
The patent changes parameters by adjusting switching rates and their harmonics. Specifically, the switching rates are designed so that their harmonics fall outside the frequency band of the desired received signal, thereby reducing unwanted spurs while maintaining digital circuit benefits.
2Device complexity
If circuit elements are used for single functions, then circuit design is simplified, but circuit imbalances introduce extraneous signals and lower performance
Solution Approach 1:
The patent implements multi-functionality by designing circuit elements that perform alternating functions. Specifically, circuit elements switch between different operational modes (e.g., sampling, holding, filtering) in alternating time intervals, allowing single components to fulfill multiple roles and reduce overall circuit complexity while maintaining performance through functional diversity.
Data Source
AI summary
A mixing module includes a plurality of switched sample modules operably for generating a corresponding plurality of samples of an analog input signal in response to a control signal. A control module generates a mixing sequence and a control signal based on the mixing sequence, the control signal including a sequence of sample positions at a sampling clock rate and a sequence of scale factors, the sequence of scale factors based on an oscillation, wherein the sampling clock has a sample period and wherein the sequence of sample positions repeats at a sample position period greater than a sample interval, the sample interval equal to the sample period times the number of the plurality of switched sample circuits.