Gain and Bandwidth Enhancement of Circular Microstrip Patch Antenna using a Circular Groove Etched Rectangular Metal Sheet Superstrate

A design of gain and bandwidth enhancement of Circular Microstrip Patch Antenna (CMPA) has been presented employing a circular groove etched in a rectangular metal sheet used as superstrate. The proposed concept is unique, and simple as flexible approach to enhance the gain and bandwidth. A rectangular shaped foam spacer has been used to provide mechanical support to place an optimized groove etched rectangular metal sheet superstrate. The proposed antenna offers about 35.5% of impedance matching bandwidth ranging between 8.45 GHz to 12 GHz with a total bandwidth of 3.55 GHz, whereas a conventional circular patch, resonating at 9.95 GHz, hardly shows about 4.8% of impedance bandwidth (480 MHz) only with co-pol. peak gain of 7dBi. In addition to the enhanced bandwidth characteristics co-pol. peak gain of 10dBi is maintained throughout the operating frequency band. There is 3dBi gain enhancement is achieved when compared to conventional CMPA. For the experimental validation, a set of antenna prototype has been fabricated using the commercially available dielectric substrate. The measured result shows similar with the simulated predictions.