Array pattern synthesis for satellite communications on-the-move

We describe the synthesis of transmit beampatterns for a multi-band array of nonuniformly spaced spiral antennas for use in geosynchronous satellite communications. Due to element size the minimum inter-element spacing is more than a half-wavelength, and the spiral elements have directional radiation patterns, complicating the synthesis problem. We describe the application of three known synthesis methods that are sufficiently flexible. We discuss the following issues: appropriate target patterns, control over the shape of the mainlobe, and the sectorization of the field of view into neighborhoods over which prestored tapering weights (synthesized offline) can be applied.