In this paper, the design and analysis of microstrip-fed low-profile, compact ultra-wideband (UWB) monopole antenna with its multiple-input multiple-output (MIMO) configurations and two band-notches characteristics are carried out. The antennas are mounted on a low cost FR-4 substrate of dielectric constant 4.4. The original shape of the single antenna element is circular with radius of 11.5 mm, and then a sector is removed from the patch (making it a Pacman-shaped antenna) to improve the impedance bandwidth. The proposed antennas provide an impedance bandwidth between 2.9-15 GHz with better than 10 dB return loss and isolation less than -16 dB and -19 dB for the first and the second MIMO configurations, respectively. Additionally, the antennas can reject the interferences from WiMAX (3.5 GHz center frequency) and WLAN (5.5 GHz center frequency).
ULTRA WIDEBAND (UWB) ANTENNAS; CIRCULAR MONOPOLE ANTENNA; MULTIPLE-INPUT MULTIPLE-OUTPUT (MIMO)