Groove Gap Cavity Slot Array Antenna for Millimeter Wave Applications

A cavity slot array antenna is designed and manufactured using gap waveguide technology. The array antenna is arranged in a single-layer metal structure without requiring any physical power divider network. The design implements high-order cavity modes for feeding the slot elements in a groove gap cavity. Thus, a single layer, moderate gain, low profile, lightweight, and low-cost antenna are resulted using the gap waveguide technology. A sample antenna with 4 x 4 slot elements is designed and manufactured by implementing the TE
₄₄₀
mode of the cavity. The antenna is fed via a coaxial line and operates at the center frequency of 37.5 GHz with the impedance bandwidth of 16%. The antenna has a broadside radiation pattern with a measured gain of 18 dBi and 3 dB gain bandwidth of 9.3%. The antenna sidelobe level is less than 12.6 dB at the center frequency.