A 76 GHz Multi-Layered Phased Array Antenna Using a Non-Metal Contact Metamaterial Waveguide

A 76 GHz phased array antenna (PAA) using waffle-iron ridge waveguides with non-metal contacts has been developed. The non-metal contact technology has the advantage of avoiding losses due to imperfect metal contacts, and also facilitates the fabrication of small-size and multi-layer stacked structures. The principle and results of the developed phase shifter, radiator and feed network are presented. For the feed network, it is shown that the phase differences between adjacent radiators are the same, which confirms the validity of the fundamental operation of the PAA. A PAA combining the feed network and 16 radiators with a size of 62 mm × 62 mm × 25 mm was realized. The characteristic of the PAA was evaluated by calculating the directivity using measured data from the radiator and the feed network. From these considerations, the PAA was found to have the capability of providing a beam tilt angle of ±18° while maintaining a gain of more than 32 dBi.