Efficient techniques for computing radiation patterns for conformal antennas mounted on arbitrary three-dimensional platforms

A procedure is presented for computing radiation patterns of conformal patch antennas mounted on arbitrarily-shaped platforms. This procedure avoids many of the disadvantages associated with typical analysis techniques for such antennas, including the necessity to reformulate a problem whenever an antenna is moved from one position to another on a platform. The technique conveniently separates the analysis of the platform from that of the antenna, then uses the reciprocity relationship to recombine this data and produce a radiation pattern. Because all of the data for the platform is computed in advance, the antenna can be moved efficiently from position to position and the new radiation patterns computed. The computation of this platform data, which involves plane wave scattering analysis, presents the only significant drawback to the use of this procedure. Complete induced surface current data due to plane wave incidence must be stored for the platform, not only for every possible incidence angle, but also for every frequency of interest. This amount of data can quickly become overwhelming, even for modern computer systems. Previously, a technique using Model-Based Parameter Estimation (MBPE) was presented for interpolating radiation patterns simultaneously in both the spatial and frequency domains.{09}This technique is adapted here to interpolate and compute the platform surface currents due to plane wave scattering. The complete mathematical formulation of the domain-decomposition and reciprocity procedure is first given for two types of platforms, infinitely-long circular cylinders and arbitrary three-dimensional platforms. Next, for each type of platform the procedure for computing radiation patterns for arrays of conformal antennas is given. Examples of computations conducted for conformal microstrip patch antennas and arrays mounted on various platforms are then given. The procedure for interpolating antenna radiation patterns using MBPE is then presented with examples, and is subsequently adapted to be applied to surface currents induced on a platform due to plane wave scattering. The example of scattering from a PEC sphere is presented for validation in both the spatial and frequency domains. Finally, plans for future research into improving this conformal antenna analysis technique even further will be presented.