A SIW cavity-backed symmetrical dual-beam self-diplexing slot antenna for mm-wave applications

Abstract This paper presents an Substrate Integrated Waveguide (SIW) cavity-backed symmetric dual-beam self-diplexing slot antenna for short-distance multiuser point-to-point communications using mm-wave frequency bands. The antenna is fed by two capacitive-gap-coupled microstrip lines, which help the antenna to operate at two different frequency bands with a self-diplexing property. Independent frequency tunability at both the operating bands can be achieved by varying the capacitive gap position along the microstrip feed lines. To enhance port isolation and achieve dual-beam characteristics the design incorporates an L-shape folded slots, centrally located shorting via, W-slot, corrugated microstrip structures and mender line slot. The beams are directed at ± $\theta = \pm 43^\circ$ with a half-power beam width of 56 ∘ each. The antenna offers peak realized gains of 5.95 and 6.21 dBi at the lower and upper band, respectively. The antenna is fabricated and measured, which shows a good agreement between simulation and measurement, confirming its suitability for short-distance multiuser point-to-point communications