Assessing the Response Time of a Frequency-Selective EMD Detector

Traditionally, the measurement of electromagnetic disturbances (EMDs) relies on field probes equipped with diode or thermocouple detectors. Some of those detectors may not adept at capturing rapidly changing electromagnetic (EM) fields, and may be plagued by slow response times that can lead to erroneous measurements. Furthermore, those detectors operate in the time domain, producing broadband EM field strength results without the ability to identify specific frequencies where EMDs occur. This paper introduces the design and assessment of a frequency-selective EMD detector using software-defined radios (SDRs). The proposed system detects and transforms undesired EMD signals from the time domain to the frequency domain via an embedded Fast Fourier Transform (FFT). When the electric field strength exceeds a predefined threshold within the SDR-based detector, it triggers a warning. To measure the speed of the SDR-based detector response to an EMD, pulse-modulated signals were selected as the test signals. The frequency hopping time is also considered a crucial element affecting the SDR-based detector response time. The experimental results for response time are subsequently subjected to a Monte Carlo-based simulation, providing a comprehensive evaluation of the SDR-based detector response time.