Antenna Characterization Method for Front-End Design of Pulse-Based Ultrawideband Transceivers

A general method is presented for the modeling of arbitrary ultrawideband (UWB) antennas directly in RF circuit simulators in order to enable simulations of circuit performance with the antennas included. The antenna modeling approach is based on S-parameter measurements, which are conducted in a semi-anechoic chamber. Analytic expressions are derived to establish the relationship between the equivalent isotropically radiated power (EIRP) and the circuit model of an antenna. Since the Federal Communications Commission uses the EIRP to assess compliance with their regulations, it is important to be able to accurately simulate its value. In addition, a procedure to model multipath channels in the circuit domain is presented. The impact of antenna characterization on transmitter design is illustrated by a finite impulse response type UWB pulse generator design example. Utilizing this antenna characterization method, it is possible to simulate the EIRP from an UWB transmitter and also evaluate the performance of a receiver design for an arbitrary multipath channel prior to fabrication.