Compact spherical near-field measurement system for UWB antennas

We have developed a compact spherical near-field measurement system suitable for UWB antennas from 3 GHz to 10 GHz. The patterns measured by this system were compared with the ones by the conventional far-field method and they agreed within 1 dB in the main beams over this wide frequency range. Because this system uses only one photonic sensor as the probe over the frequency range, the system is suitable for the pattern measurements of UWB antennas. Moreover, because the photonic sensor is very small compared with the wavelengths and very lightweight, the system can be made in a compact and simple form. Therefore the system can be installed and used in a usual experimental room.