Millimeter-wave and Terahertz Power Meter Characterisation at W-band Frequencies

Traceability for power measurements at high millimeter-wave and terahertz frequencies presents significant challenges since traditional waveguide micro-calorimetry systems are only readily available at frequencies up to 110 GHz. There are, however, different types of commercially available power meters which operate at frequencies above 110 GHz, where a lack of traceability means the accuracy and associated uncertainty of measurements using these power meters is not well understood. This paper describes the characterisation and traceable calibration of a commercially available waveguide power meter (VDI Erickson PM5) which is designed to operate from 75 GHz to 3 THz, using appropriate waveguide tapers. This includes an assessment of the overall system performance along with an evaluation of the uncertainty in measurements made using the system. The assessment is carried out at W-band (75 to 110 GHz) by comparison with micro-calorimeter systems which are used as primary standard power measurement systems at these frequencies.