A multi-scale technique for the electromagnetic modeling of active antennas

In this paper, a scaling approach has been used for the electromagnetic modeling of an active element integrated with a radiating structure. From the small size of the active element to the large planar radiating surface, many scale levels are present in an active antenna. We propose a new technique for taking into account the multi-scale nature of such structure in electromagnetic simulations. A N-port is first computed in order to model the active antenna at a given scale level. Then the cascade of these N-ports allows the electromagnetic modeling of the overall antenna. The computation of the driving-point impedance and the current distribution on an active antenna are presented and compared with classical simulation techniques. Accurate numerical results are obtained with a substantial reduction in computer time and memory compared to direct full-wave electromagnetic analysis.