Whitepaper
Improving EMC Compliance Testing
This Keysight application note details Time Domain Scan (TDS) technology as a means of improving throughput in EMC compliance testing. Traditional frequency domain scanning relies on collecting data point-by-point across the spectrum, adhering to dwell times specified by standards like CISPR and MIL-STD-461 (ranging from 15ms - 15s). TDS utilizes Fast Fourier Transforms with high overlap (~90%) over wider acquisition bandwidths (1-10 MHz or greater) to simultaneously collect data across multiple resolution bandwidths, effectively reducing scan time. A pre-scan example in the 30MHz – 1GHz range using a Keysight N9038A MXE receiver showed TDS reducing scan time from approximately 10 hours (frequency domain with 120kHz RBW & 10ms dwell) to under 30 minutes. While widening preselector filters for faster acquisition can reduce overload protection, the paper suggests careful consideration of this trade-off against sensitivity and overall measurement time savings.