New semi-elliptical and trapeziform dipole antennas for ultra-wideband communications

A microtrip-fed semi-elliptical and trapeziform dipole antenna (MFSETDA) which has a small size of (34 mm times 30.2 mm) is presented and designed for ultra-wideband (UWB) communications in this paper. The MFSETDA has large bandwidth covering the frequency from 3.1 to 10.6 GHz, radiation patterns similar to those of conventional dipole antennas. The proposed microtrip-fed antenna is easy to be integrated with radio-frequency (RF) /microwave circuitry for low manufacturing cost. The designed band-notched MFSETDA operates from 3.116 to 10.637 GHz for voltage standing wave ratio (VSWR) les 2. By etching a folded U-slot in the funnel-shaped radiating patch, a stopband about 718 MHz (from 5.110 to 5.828 GHz) using in IEEE 802.11a wireless local area network (WLAN) can be obtained. Simulated results show that these antennas are suitable for UWB applications due to their high performances.