Substrate Integrated Waveguide Cavity Backed Wideband Slot Antenna for 5G Applications

Abstract

In this article, a study of wideband substrate integrated waveguide (SIW) cavity based slot antenna is presented. The proposed antenna consists of a U-shaped slot etched in the ground plane which helps in achieving the wideband behaviour. A detailed analysis of the SIW cavity and prediction of various modes propagating inside it using accurate design equations are discussed. An equivalent circuit modeling of the proposed antenna along with surface current distributions at various resonating frequencies is also performed. Parametric study on various parameters to improve the performance in terms of wide impedance bandwidth, gain and efficiency levels are also discussed in detail. The fabricated prototype of the proposed SIW antenna shows the reflection coefficient S11 <= 10 dB in frequency range from 26.20-30.30 GHz (14.51%) which are in good agreement with the simulated results. A peak gain and maximum radiation efficiency of 7.65 dBi and 91.29%, respectively. A low variation in peak gain (+/-0.26 dBi) and radiation efficiency (+/-0.09%) within the operating frequency range is seen. A good matching characteristics along with good level of gain, radiation efficiency levels and stable radiation patterns makes the proposed antenna a suitable candidate for 5G applications.