Wideband and Compact Magneto-Electric Dipole Antenna for Electromagnetic Medical Imaging Systems

A wide band low profile directional magneto-electric antenna is presented. The antenna consists of a half-wavelength bow-tie electric dipole and a one wavelength circular magnetic dipole, both printed on different sides of an FR-4 substrate. The electric dipole antenna is directly fed by a Subminiature Version A (SMA) connector, whereas the magnetic loop is excited using proximity coupling. Two parasitic elements are designed to improve the bandwidth and increase gain. The antenna has wide frequency bandwidth of 80% at 0.7-1.65 GHz with compact size of 0.3 λ0× 0.2 λ0× 0.01 λ0 (where λ0 is wavelength at lowest operation frequency). The antenna achieves a maximum realized gain of 6 dB with peak front to back ratio (FBR) of 15 dB.