Abstract
Different designers used different substrate materials to design sub-6GHz 5G antennas, therefore, it becomes imperative to carry out different investigations and analysis on the common available substrate materials so as to serve as a research guide for the future antenna designers. In this paper, a comparative study was presented on inset feed rectangular microstrip patch antenna using five different substrate materials, namely; the RT Duroid 5880, FR4 glass epoxy, Taconic TLC-32, Rogers RO4003C and Bakelite at 6GHz operation frequency with a 1.5mm substrate thickness for sub-6GHz 5G applications. All the performance parameters like the VSWR, return loss, bandwidth, directivity, gain and the efficiency were analyzed and investigated using Computer Simulation Technology (CST) studio suit 2016. The RT Duroid antenna present the highest radiation efficiency of 81% with an optimal gain and directivity of 5.934dB and 7.783dBi respectively, while the FR4 antenna gives the highest bandwidth and return loss of 318.5MHz and -31.320dB respectively. The best compact size of 10.90x14.68mm and a perfect match with VSWR of 1.0 was achieved by the Bakelite antenna. The RO4003 and TLC antennas maintained an average performance in between. it can be concluded that, for the designers that want a high gain, high directivity and high efficiency, should go for the RT Duroid substrate material while for those that need high bandwidth and high return loss, should go for the FR4 antenna and for a compact size, the Bakelite antenna should be given preference over the rest.

Key words: MSAs, Dielectric Constant, 5G, sub-6GHz, loss tangent, substrate material