A Semi-Elliptical UWB Folded Dipole Antenna

In this paper, a novel structure of a semi-elliptical folded dipole for ultra-wideband (UWB) receiving applications is discussed. This proposed antenna has a directive radiation pattern resulting in a high gain over the bandwidth. The design uses a planar technology including a microstrip line to slot line transition and optimized curves to obtain a measured impedance bandwidth of 2.3-26 GHz with the condition of S11 < -6 dB (level accepted for receiving antenna) and meets S11 < -10 dB in several bands. Additionally, the simulated gain ranges from 5 dBi to 9.5 dBi across the entire bandwidth with an efficiency of at least 75%. This antenna model offers a reconfiguration capability. The symmetrical feeding used in this antenna creates the directive behavior. Characteristics of this semi-elliptical folded dipole antenna make it suitable for modern wireless communications, such as 5 G around 3.5 GHz, and easy to integrate in antenna arrays (MIMO systems). The four ports of the antenna also make it a candidate for radiation pattern reconfigurability applications reducing in this way the number of elements in network antennas.