Design and Improvement of Step Slotted Microstrip Monopolar Patch Antenna using Defected Ground Structure (DGS)
A new low profile and broadband monopolar patch antenna is proposed. Previously, long rectangular patch antennas have been designed with a compact structure and high gain, but these antennas do not have the required monopolar radiation pattern. On the other hand there have been patches designed to have wide bandwidth by employing thick substrates. However, the profile of such antennas may be too high for certain applications. We propose a low profile patch antenna with wide bandwidth, high gain, high directivity and monopole like radiation pattern. The proposed antenna has a bandwidth of 1.396% and gain of 4.75 dBi with monopole like radiation pattern at 5.156 GHz for an infinite ground plane. Using Defected Ground Structure (DGS) resonant frequencies are obtained at 3.836, 5.18 and 6.644 GHz, with bandwidth of 18.902% and gain of 8.66 dBi.
