Intercomparison of Standard Gain Horn Antennas at $W$ -Band

An intercomparison of two W-band (75-110 GHz) standard gain horn antennas of nominal gains 24 and 27 dB has been performed at the Korea Research Institute of Standards and Science (KRISS), National Physical Laboratory (NPL), and National Institute of Standards and Technology (NIST). The measurement parameters for this comparison are the power gain and complex reflection coefficient of the traveling standards measured at 75, 95, and 110 GHz, and, as an option, the swept-frequency power gain measured over the frequency range of 75-110 GHz with a finite frequency step. All participants performed the fixed-frequency antenna measurements, whereas the swept-frequency antenna measurements were carried out by the NPL and the NIST. This paper describes the comparison and its measurement results with uncertainties. Generally, the agreement between the results in all the measurements is within the uncertainty of each participant, except for fixed-frequency gain results of the high-gain antenna at 110 GHz, reflection coefficient results at some fixed frequencies, and swept-frequency gain results of the high-gain antenna in the low- and high-frequency regions of the W-band.