Low Profile, Broadside Radiating, Electrically Small Huygens Source Antennas

Abstract

It is demonstrated numerically that a metamaterial-inspired, low profile (height approximately λ/80), electrically small (ka = 0.45) Huygens source antenna can be designed to radiate at 300 MHz in its broadside direction with a high radiation efficiency and a large front-to-back ratio. Two electrically small, near-field resonant parasitic (NFRP) antennas are first designed. Both are based on a coax-fed dipole antenna. An electric dipole response is obtained by combining it with a tunable Egyptian axe dipole (EAD) NFRP element. A magnetic dipole response is obtained by spatially loading the driven dipole with tunable, extruded capacitively loaded loop (CLL) NFRP elements. The driven dipole and the EAD and CLL NFRP elements are combined together and retuned to achieve a broadside radiating Huygens source antenna. Two different designs, one with two CLL elements and one with four, are obtained, and their performance characteristics are compared.