International intercomparison of horn gain at X-band

An international intercomparison of horn gain and polarization measurements at X-band has previously been completed. There were seven participating laboratories with the National Institute of Standards and Technology serving as the pilot laboratory. Two X-band pyramidal standard gain horns with a nominal gain of 22 dB served as the traveling standards. Quantities measured included on-axis fixed frequency gain at 8, 10, and 12 GHz, swept frequency gain between 8-12 GHz and polarization characteristics at the three fixed frequencies. All laboratories performed the fixed frequency-gain measurements. The swept-frequency and polarization measurements were optional, with four laboratories performing swept-frequency measurements and three laboratories measuring polarization. The results of the gain measurements generally agreed within the reported uncertainties which were of the order of 0.1 dB or less.