Optimum design of yagi‐uda antenna for millimeter‐wave imaging

A millimeter-wave imaging array is proposed in which many Yagi-Uda antennas are placed on a dielectric lens. By changing the dimensions of these antennas, the impedance matching with the detector is optimized. At the same time, a radiation pattern matched to the incident beam from the focusing optics is realized. The crosstalk between the adjacent detectors on the array is measured. An optimum spacing is derived and a good imaging property is realized. The present imaging array is suitable for MMIC and is applied in practice for plasma measurement for nuclear fusion research.