The R&S® SMR family comprises six base models designed as CW generators with pulse modulation capability. The six models have a common lower frequency limit of 1 GHz and provide frequency coverage up to 20 GHz (R&S® SMR20), 27 GHz (R&S® SMR27), 30 GHz (R&S® SMR30), 40 GHz (R&S® SMR40), 50 GHz (R&S® SMR50) and 60 GHz (R&S® SMR60). The lower limit can be expanded to 10 MHz by the optional Frequency Extension 0.01 GHz to 1 GHz (R&S® SMR-B11).