Printed Slot and Wire Antennas: A Review

The first part of this paper focuses on printed slot antennas. Starting with discussions of a narrow modified slot and a wide slot fed by a microstrip line, we proceed to a topic of generation of a circularly polarized beam. In addition, a rectangular slot antenna fed by a coplanar waveguide is described. The modification of a rectangular slot into an elliptical slot for enhancing the bandwidth is also presented. The second part of this paper covers wire antennas, first presenting the theoretical treatment and then the radiation characteristics of various configurations. It is described that a multiloop antenna exhibits multiband characteristics; a spiral antenna has wideband characteristics with the help of resistive material; and a helical element, having only the region, radiates a circularly polarized wave. An inverted F-antenna (IFA) backed by an electromagnetic band gap (EBG) reflector and a composite helical and spiral (CHES) antenna are then presented, both radiating a tilted beam. Next, a curl antenna array that has an unrivaled aperture efficiency of more than 90% is introduced.