Importance of receiver dwell time in emission measurements

The EMC regulations call for conducted and radiated emission tests for majority of electrical and electronic equipment. Most of the relevant standards specify only the resolution bandwidth and detection modes to carry out the tests without specifying the dwell time selection. The choice of dwell time along with resolution bandwidth is an important factor because it affects the measurement results of conducted and radiated emission. The selection of proper dwell time must be compatible with the various operational and functional modes of the EUT and its accessories. This paper describes the effects of receiver dwell time on EMI emission results. A few suggestions are also proposed in this paper to identify the proper dwell time selection for emission measurements.