A Low-Profile High-Gain Slotted Waveguide Antenna Array With Grooved Structures

This letter reports the development of a low-profile and high-gain slotted waveguide antenna array, aiming the FR2 5G frequency range and operating in the 26 GHz band. The proposed array relies on 27-sloped slots, positioned onto the WR28 standard waveguide broadside wall with six pairs of metal grooved structures placed parallel to its axis. Experimental results demonstrate the achievement of 3.41% fractional bandwidth from 25.88 to 26.78 GHz, 27.7 dBi gain and half-power beamwidths in the azimuth and elevation planes equal to 10° and 3°, respectively. The use of metal-grooved structure realizes a gain enhancement of 9 dB, and results in a high-gain antenna array, which is based on a very simple and unique excitation.