Compact Defected Microstrip Antenna for Wideband Spectrum Sensing Cognitive Radio Applications

This paper discusses a frontend device wideband antenna for wideband spectrum sensing for cognitive radio applications. P-shaped slots in the radiating patch and a circular bandgap structure on the ground plane compose up the proposed wideband antenna. Slot structures are introduced in the design to achieve compactness. For this work, a FR4 substrate with a thickness of 1.6 mm is utilized. 12 mm x18 mm is the total substrate design geometry. This designed wideband antenna has a sensing capability from 4.74 GHz to 10.60 GHz. The antenna gain and radiation efficiency at the resonant frequency 5.5 GHz are 2 dB and 98 % respectively. The 5.5 GHz frequency of operation is used for WLAN applications. At 9 GHz, the gain and radiation efficiency are 4.2 dB and 96.94 % respectively. For space-borne applications, a 9 GHz frequency of operation is used.