A pair of millimeter-wave frequency converters from Rohde & Schwarz aid in performing power-dependent measurements on amplifiers and mixers. Models R&S ZVA-Z90E and R&S ZVA-Z110E operate over frequency ranges of 60 to 90 GHz (E-band) and 75 to 110 GHz (W-band), respectively, and are designed for use with a vector network analyzer (VNA), such as the firm's R&S ZVA or R&S ZVT instruments. Both offer electronically adjustable output power levels and dynamic ranges in excess of 110 dB. Both also support true differential four-port measurements.