SIW-based Circularly Polarized Slot Antenna Array for Millimeter-Wave Applications

Abstract

In this paper, a substrate integrated waveguide (SIW) based circularly polarized slot antenna array is presented for millimeter-wave (mm-wave) wireless applications at 28 GHz. The proposed antenna geometry comprises two orthogonal slots engraved on the top layer of the SIW cavity. Upon optimization of slot dimensions and their positions inside the SIW cavity, one left-handed circularly polarized (LHCP) radiation has been obtained at 28 GHz with a decent maximum gain of 6.57 dBic in the broadside direction. To improve the gain of the antenna, a 1x2 antenna array with a SIW feed network has been designed and demonstrated. The array geometry exhibits the maximum gain of 9.25 dBic with an impedance bandwidth of 1.77 GHz (27.33 - 29.10 GHz) and an axial ratio bandwidth of 200 MHz (27.95 - 28.15 GHz). Furthermore, the structure features a simple topology, high efficiency, and low cross-polarization, which makes it suitable for mm-wave applications. © 2022 IEEE.