Phase measurements of millimetre wave antennas at 105-190 GHz with a novel differential phase method

The application of conventional antenna phase measurement methods becomes increasingly difficult above 100 GHz. The main problems are the complexity of measurement set-ups and errors caused by the flexible cables or rotary joints needed in the system. To overcome these problems, a novel differential phase measurement method has been developed and used to measure phase centre positions and phase patterns of two corrugated horns at 105-115 GHz and 176-190 GHz. In spite of the simplicity, the differential phase method gives accurate results. Good agreement between the measured values and theoretical values, calculated with the modal matching technique, were obtained.