Design of a 4 × 6 Planar Slot-Structured Antenna Array With Substrate-Integrated Waveguide for Sub-Terahertz Applications

This paper presents a planar slot structure antenna array with a simple structure of a substrate-integrated waveguide for D-band communication bands. This antenna achieves wideband and high gain characteristics. The antenna is fed by a power divider in the corporate structure and a transition structure is designed from the WR-6.5 metal waveguide to the SIW. To improve bandwidth, a cavity is added to the transition structure to provide multiple propagation modes. The proposed antenna is designed incrementally, from a $2\times 6$ antenna array to a $4\times 6$ antenna structure. After verifying with simulations and measurements, the designed $4\times 6$ antenna array has a frequency coverage of 130-131, 135-136, and 138.7-142 GHz and an average radiation gain of about 15 dBi. The proposed antennas are considered ideal for the D-band communication system. Therefore, the proposed antenna is compact, easy to integrate in RF circuits, and high gain, which makes it suitable for development and application in D-band communications.