Ultra-Wideband, Low-Profile, Electrically-Small Antennas Utilizing Artificial Magnetic Conductors

The proposed miniaturized antenna takes advantage of two innovations. These include the novel antenna design concept of coupled sectorial loops and a wideband artificial magnetic conductor substrate utilizing a combination of dielectric and ferromagnetic (ferrite) materials. At its lowest frequency of operation, a coupled sectorial loop antenna (CSLA) can be designed to have maximum dimensions of 0.1£fm„e0.35£fm (where £fm is the wavelength at the lowest frequency of operation) with impedance bandwidths in excess of 10:1. In this proposed work, we will take advantage of the wideband properties offered by the CSLA concept and utilize various modified miniaturized versions of this antenna as the starting point to further decrease its lowest frequency of operation (or equivalently its electrical dimensions). Moreover, we will utilize a wideband artificial magnetic conductor (AMC) substrate and a composite feeding scheme to even further reduce the lowest frequency of operation of the antenna without increasing its occupied area. This will result in an electrically small antenna with maximum dimensions of 0.05£f0„e0.15£f0 with an impedance bandwidth ranging from 300 MHz to 3.0 GHz.