Design and Analysis of Broadband Monopole Antenna with Dual Circular Polarization for C-Band Applications

The purpose of launching communication satellites is to transmit and receive the signal throughout the Earth, thereby making fast communication between widely separated points. The first frequency band that was allocated for communication purpose was C-band (4-8 GHz). Achieving a compact size with improved bandwidth, gain, directivity of an antenna has been an important issue, especially for the satellite based application. Using dual orthogonal microstrip tapered feed lines, a broadband monopole antenna having dual circularly polarization is designed for C-Band applications. The modified ground plane structure generates circular polarization. Once CP is generated new challenges such as wide axial ratio, impedance bandwidth will arise. The design of combination of Inverted L-shaped Strips (ILSS) and L-Shaped Strips (LSS) along radiating edges of monopole maximizes the axial ratio and design of bevel at lower edge of monopole will improve the reflection coefficient for wideband impedance matching. The antenna is designed and simulated using HFSS software of version 17. The frequency of operation is from 1.4 to 9.0533 GHz (146%) with maximum reflection coefficient of -43.2321 dB. Since good 3-dB AR Bandwidth is achieved for the range of 4.84 to 7.52 GHz, this antenna can be used for the C-Band applications like WIFI (5.15-5.85GHz), WIMAX (5.15-5.85GHz), WLAN (5GHz, 5.2GHz, 5.8GHz) and C-band wireless system. Peak gain of 4.958 dB is achieved at 7.5 GHz and peak directivity 5.1108 dB is achieved at 5.7 GHz respectively.