Compact CP Monopole Antenna with asymmetrical Modified Ground Plane for Wideband Characteristics

Abstract

an antenna design comprises of modified or defected ground structure (MGS/DGS) with inverted F-shaped printed structure presented for broad impedance bandwidth along with axial ratio bandwidth (ARBW) is proposed. At the bottom surface of FR-4 substrate, the extended rectangular ground plane is modified by inserting an asymmetrically F-shaped slot. Further to achieve the broader axial ratio performance, a small and narrow slit is removed from the edge of partial ground plane. Proposed antenna is optimized for optimal performance before fabrication and measured for the validation with simulated results. From the simulated and measured results, it is confirmed that the antenna can be competently produced a fractional impedance bandwidth (< -10 dB) nearly ≈ 37 % and simulated 3-dB axial ratio bandwidth ≈ 29.25 %, respectively. The simulated antenna gain is varied from 2 dB to 4.35 dB within the 3-dB ARBW with maximum gain of 4.35 dB. For the proposed antenna, the cross polar suppression was noticed around 17 dB along with wide 3-dB beamwidth.