RF Front-End Jammer Detection Circuit
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Solution Overview
Problem
Conventional RF front-end circuitry fails to detect jamming signals outside the baseband filter bandwidth, leading to signal saturation and reduced signal-to-noise ratio due to attenuation of these signals in the analog-to-digital converter output.
Innovation Solution
A jamming detection circuit is implemented prior to the analog baseband filter, using counters to determine the power of the received signal and count instances where it exceeds a threshold, allowing the automatic gain control logic to adjust the analog gain based on the amount of jamming detected over a measurement window.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional RF front-end circuitry uses baseband filter to reject out-of-band signals, then selectivity is improved, but jamming signals outside the filter bandwidth cause saturation and reduce signal-to-noise ratio
Solution Approach 1:
The patent performs jamming detection before the analog-to-digital converter by measuring the power of received signals and comparing it against thresholds. This preliminary detection allows the system to identify jamming conditions and adjust the analog gain accordingly, preventing saturation from occurring in the first place
Solution Approach 2:
The patent implements a feedback mechanism where the detected signal power is continuously monitored and used to control the analog gain. When jamming is detected (signal power exceeds threshold), the gain is reduced; when no jamming is present, the gain is increased. This closed-loop feedback optimizes the signal-to-noise ratio while protecting against jamming saturation
2Measurement precision
If analog gain is increased to improve signal-to-noise ratio, then sensitivity is improved, but saturation occurs when jamming signals are present
Solution Approach 1:
The patent makes the analog gain dynamic rather than fixed. The gain is continuously adjusted based on real-time jamming detection results. When jamming is detected, the gain is reduced to prevent saturation; when no jamming is present, the gain is increased to improve signal-to-noise ratio. This dynamic adaptation resolves the contradiction between sensitivity and saturation
Solution Approach 2:
The patent changes the gain parameter based on detected jamming conditions. By monitoring signal power and comparing it to thresholds, the system adjusts the analog gain parameter in response to changing environmental conditions, optimizing performance across different operating scenarios
3Device complexity
If conventional systems ignore out-of-band signals, then device complexity is reduced, but jamming detection capability is lost
Solution Approach 1:
The patent extracts the jamming detection function from the main signal processing path by implementing a separate power measurement and comparison circuit. This extracted sub-system monitors signal power independently and provides control signals for gain adjustment, adding minimal complexity while enabling jamming detection capability
Data Source
AI summary
Certain aspects of the present disclosure generally relate to jamming detection for radio frequency (RF) front-end circuitry. For example, certain aspects provide an apparatus having a first counter configured to count a number of times that a power of a reception signal exceeds a first threshold. The apparatus also includes a second counter configured to count a number of measurements of the power of the reception signal. The apparatus further includes control logic having a first input coupled to an output of the first counter and having a second input coupled to an output of the second counter. The control logic is configured to determine an amount of jamming over a measurement window based on the number of times that the power of the reception signal exceeds the first threshold and on the number of measurements.