Compact Modeling of UWB Antenna 3-D Near-Field Radiation Using Spherical Vector Wave Expansion and Cauchy Methods

The purpose of this letter is to model the three-dimensional radiation pattern of an ultrawideband antenna in near-field region. This compacting process can be established by combining spherical vector wave expansion and Cauchy methods. Spherical basis possesses the advantage of handling both radial and angular behavior, whereas the Cauchy method allows modeling of frequency dependence. This theoretical approach is assessed by modeling the simulated and measured data of an exponential tapered slot antenna. Very interestingly, this model can provide radiated field at different distances from the antenna.