Impedances of a Cubical Quad Antenna

Abstract

Rectangular loop antennas and short electric dipoles are two of the oldest antennas in existence. In 1888, twenty years after Maxwell invented his famous Maxwell's equations, Hertz used these two antennas to prove that high frequency electric energy sources could radiate electro- magnetic waves. The "Cubical Quad" or, simply, "Quad" antenna is a development of the rectangular loop antenna. It consists of a pair of square loops, one-quarter wavelength on a side or one wavelength around the periphery; one loop being driven and the other used as a parasitic reflector. The separation between the two is usually of the order of 0.15 to 0.2 wavelength, with the planes of the loops parallel. While studying the properties of this antenna, it was discovered that little had been done to develop it from a theoretical aspect. The purpose of this thesis is to obtain values of the self and mutual impedances existing in such an antenna array. The values are obtained from mathematical analysis and experimental measurements and may be used in field pattern and gain calculations.