Effects of Slots On Resonant Frequencies of a Microstrip Patch Antenna

In this paper, a compact multiband rectangular microstrip patch antenna using slots to obtain multiple resonating frequencies, is discussed. Slots can be introduced for increasing the bandwidth, miniaturization and introducing multiband characteristics. Rectangular slots are introduced in the radiating patch, arranged in the shape of a “swastika”. Multiband characteristics is achieved due to spiral arrangement of the slots. The microstrip patch antenna is coaxial fed. FR4 epoxy resin is used for the substrate because of its rigid structure and lossy nature which enhances radiation effects. Slots of various dimensions and positions make up a swastika slot. Impact of each slot on the resonant frequencies of the RMSA is studied, their reflection coefficient analyzed and presented here.