High-efficiency wide-band double-layer slotted hollow waveguide array antennas by diffusion bonding of laminated thin metal plates

We fabricate and measure three types of double-layer slotted waveguide array antennas by diffusion bonding of laminated thin metal plates. Etching metal plates gives high precision at low cost and diffusion bonding gives perfect electrical connection in the slotted waveguide array in millimeter-wave bands. Corporate feed is adopted to increase the bandwidth of a series-fed array antenna. A 38GHz antenna with partially corporate feed and transverse-slot termination gives 81.4% peak efficiency with 34.4dBi at 38.75GHz. An 83GHz antenna with partially corporate feed and PMC termination gives 32.4dBi peak gain with 83.0% efficiency and 9% bandwidth for 1dB down gain. A 60GHz antenna with full corporate feed gives more than 32dBi and about 80% efficiency over about a 5GHz bandwidth.