Electrooptic mapping and finite-element modeling of the near-field patternof a microstrip patch antenna

A comprehensive electrooptic field-mapping technique is applied to the char acterization of near-field radiation patterns above a microstrip patch ante nna. The amplitude and phase maps of three orthogonal electric-field compon ents, measured using electrooptic crystals above the patch, also have revea led the transition from the near field to the far field of the radiation pa ttern, In addition, experimental results have been compared with a finite-e lement method (FEM) simulation, The measurements show superior results to t he FEM simulation, especially in terms of spatial resolution and data acqui sition times. Furthermore, the scattering parameter S-11 for the patch ante nna has been calculated from the electrooptic measurement results of standi ng waves on the feeding line and compared with results from a conventional network analyzer.