US Patent 7106790 Method and apparatus for measuring a signal spectrum

A spectrum analyzer used for making a spectrum emission mask measurement reorganizes execution of the measurement so that all frequency bands to be measured at the same resolution bandwidth are measured in a single sweep, extending between the extreme frequency limits of those bands, thereby avoiding setup delays involved in specifying successive measurements for each band individually. Portions of each measurement which correspond to frequency bands to be measured at the respective resolution bandwidth of that measurement are extracted, resized as necessary, and assembled into a complete spectrum measurement.