2002 · 77 citations · 0 references
EngineeringElectrical EngineeringAntennasElectromagneticsMicrowave EngineeringAntenna DesignAntenna Impedance MatchingBroadband AntennasMicrowave AntennasPlanar AntennasUltra-wideband CommunicationAntenna Input ImpedanceDipole AntennasImpulse Radio Ultra-widebandInput ImpedanceInput Impedance MatchingResonant FrequencyTriangular ElementsUltra-wideband Antennas
When a typical narrowband antenna is excited by an ultra-wideband (UWB) impulse, the antenna rings at its resonant frequency, stretching out the waveform in time. A resonant antenna, like the bow tie, discone, or bicone have been available for years. A bow tie has a relatively high input impedance, and requires a matching balun to make it useable with a 50 /spl Omega/ system. A discone or a bicone antenna is more suitable for use with UWB impulses, but these are 3-D structures that are difficult to manufacture. The "diamond dipole" design arose from a long search for an antenna that combines an ultra-wideband, non-time dispersive response with a matched input impedance: all qualities essential for a successful ultra-wide band impulse radio system. A diamond dipole is an inverted bow tie with isosceles triangular elements whose height and base are scaled to be 1/4 /spl lambda/ at the center frequency of interest.