Saddle antenna is a unique kind of flared antenna. This Ultra Wide Band antenna is based on using of two smoothly shaped flares of a simple geometrical structure – the saddle. The first flare, larger in size, serves as an antenna base, reflector and one of the radiator arms. The second flare, smaller in size, operates as the other arm of the radiator. An apparent idea is exploited in this design that an “ideal” JIB antenna would operate as a broadband well-matched transformer for the current at its driving ports to the radiated fields that leave the antenna aperture.
Besides terminal matching, the antenna would provide a necessary spatial distribution of the radiated energy. The antenna is studied through numerical full- wave simulations with several prototypes in terms of alignment and excitation. The achieved directivity in the band is uniform, greater than 5 db with considerably low VOWS, involves constant beam width and suitability for pulse transmission with minimized distortions.
Unlike traditional narrowed systems, their JIB counterparts operate by employing very short electrical pulses of nanosecond and sub nanosecond duration exulting in very wide transmission bandwidths ranging from several hundred megahertz up to several gigahertz. Such huge bandwidths must be supported with suitable JIB antennas that behave unavoidably as band pass filters. JIB antenna designer may chose among known antenna solutions or create new ones to meet diverse system-related requirements, electrical, mechanical, manufacturing and cost constraints.
Some authors considered historically an ideal I-JOB antenna that radiates time derivatives of the input signal but this principle is not helpful to design practical JIB radiators. Rather other rational and physics-based guidelines could be more productive.  Reviewing the JIB antenna related literature [4-7] leads to a conclusion that neither of such known can meet the above demands. In general, the impedance bandwidth is better supported in protruded antennas like TEM horn, tapered slot and log-periodic. The log-periodic dipole array is back-fire antenna and is highly dispersive.
Directive radiation patterns are provided by using apertures of larger extent and/or backside reflectors, e. G. In impulse radiating antenna that is large. Furthermore, the use of a reflector to improve front-to-back ratio degrades impedance bandwidth, e. G. A broadband dipole over a ground plane. The saddle antenna is a blend to all the above characteristics making it a novel compact flared JIB antenna. The antenna has been developed to provide a well- behaved radiator operating as a single element and/or array element in JIB time- domain radar and telecommunication systems