The hybrid slot, a low-profile energy-density antenna

Low-profile antennas offer significant mechanical advantages over monopole antennas for mobile communications. At UHF and above, the required horizontal dimensions become reasonable. This paper describesa multi-port, stripline-fed, cavity-backed slot antenna which has several unique features that offer additional advantages over whip antennas for UHF mobile communications. (1) The reflection coefficient is small over a wide band. (2) Depending upon the external feed network, omnidirectional or one of several directive patterns can be selected. (3) The antenna responds to both the electric and magnetic fields to combat fading ina standing wave field.