Study of microstrip-line inset-fed and two-layer electromagnetically coupled rectangular patch antennas

This paper presents the parametric study of a microstrip-line inset-fed rectangular patch antenna and a two-layer electromagnetically coupled (EMC) rectangular patch antenna. The influence of the inset position and the air thickness between the two layers on input impedance, resonant frequency, and bandwidth is investigated by using software IE3D. The final results show that the inset depth is the primary factor affecting the matching and the air thickness mainly affects the bandwidth. The tested two-layer antenna works at 6.1 GHz with a bandwidth (S₁₁ ≤ -10dB) of about 11%, 8-dBi gain. The 3-dB beamwidth in the E-plane and H-plane is 57° and 70°, respectively.