Wideband Design of Circular Microstrip Patch Antenna using Rectangular Metal Sheet Superstrate for X-Band Applications

A wideband circular microstrip patch antenna (CMPA) has been presented employing a rectangular metal sheet superstrate. The proposed concept follows a unique, simple, and a flexible design approach to enhance the bandwidth of a circular patch. A simple change in the conventional antenna geometry has been suggested by adding a rectangular metal sheet superstrate, placed symmetrically above the patch. A cylindrical shaped foam spacer has been used to provide mechanical support to the optimized superstrate. The proposed antenna offers about 36% of impedance matching bandwidth ranging between 8.46 GHz to 12.06 GHz with a total bandwidth of 3.6 GHz. Whereas, a conventional circular patch, resonating at 9.96 GHz, hardly shows about 4.8% of impedance bandwidth (480 MHz) only. In addition to the enhanced bandwidth characteristics, the proposed antenna, also reveals a little increase in the gain throughout the operating frequency band. For the experimental validation, a set of antenna prototype has been fabricated using the commercially available dielectric substrate. The measured result is very closely agreed with the simulated predictions.