Coupled microstrip antennas for wider bandwidth

摘要

Narrow bandwidth available from microstrip patch radiators has been recognized as the most significant factor limiting the applications of this class of antennas. Different approaches for increasing the bandwidth available from microstrip antennas include: i) use of thicker substrates with low εr [1], (ii) use of multiple patches in one plane [2], (iii) use of multiple patches stacked vertically [3], and (iv) use of broadband impedance matching networks [4], One of the configurations [2] in the group (ii) makes use of rectangular patches gap-coupled along the non-radiating edges. This particular configuration appears very attractive as the layout can be made compact [5] thus avoiding the use of large substrate area and consequential degradation in radiation pattern over the operating frequency range.