A Low-Profile Hollow Waveguide Slot Array Antenna with Full-Corporate Feeding Network at K-Band

A hollow waveguide slot array antenna with a total volume of 338x106.5x28.9 mm(3) is proposed as a sensor for millimeter-wave short-range radar applications at K-band. The proposed antenna consists of a radiating slot plate with 8x32 slots, a middle plate with 64 cavities and apertures, and a full-corporate-feeding network. The antenna structure is fabricated with these three parts in which the sub-array feeding technique is employed. The proposed antenna accomplishes high gain and efficiency with a straightforward fabrication, and it operates between 23.72-25.30 GHz frequencies with 6.45% bandwidth. The measured directivity is 32.1 dBi, and the realized gain of the antenna is attained as 30.84 dBi at 24.5 GHz center frequency with 74.8% total efficiency. In spite of fabrication imprecision and connector losses, these measurements are obtained sufficiently consistent with simulations.