Statistical parameter measurement of unwanted emission from microwave ovens [digital mobile radio interference]

Microwave ovens operated in the 2.45 GHz band emit broadband noise that might possibly interfere with digital mobile communication systems in 1-3 GHz bands when their terminals are used near the ovens. We therefore measured the basic properties of unwanted emissions from microwave ovens in both time domain and frequency domains, and found that out-of-band emission occurs when the magnetron oscillation is transient or unstable. We also measured the statistical distributions of the noise envelope at 1.9 GHz band-amplitude probability distribution, crossing rate distribution, pulse spacing distribution and pulse duration distribution-in order to obtain the information necessary for evaluating the degradation of the performance of communication systems