Characteristics and Usage of the Ram's Horn Antenna

The transverse bilateral helical (TBH) antenna, also known as the ldquoram's horn antennardquo due to its appearance, has been developed for portable device applications with special attention given to minimize the influence of human body tissues on antenna performance. Being an electrically small resonant antenna, its operation may be viewed as a radiation system comprised of an electric dipole in tandem with a collection of magnetic dipoles to produce an almost isotropic azimuthal radiation pattern that can withstand the shielding effects of human body tissues. Rationale for the design of this antenna and its characteristics are explained in light of measurement and simulation results obtained for this antenna and those of a normal-mode helical antenna and a bent helical antenna of similar electrical dimensions.