Non-Planner GPS Receiving Antenna

It is desirable to have small aperture for a user, but with better antenna gain toward GPS satellites and discrimination against jammers at low elevations. SDS proposes a methodology which will utilize multiple high gain spot beams from a non-planer array providing many AJ links simultaneously between GPS satellites and the user. The multi-beam antenna not only provides connectivity but also ensures isolations and discriminations against interference at low elevation angles. We will use AJ performance of a GAS-1 antenna as a key reference for comparisons. Multiple beams will be implemented via digital beam forming (DBF) technology, which enable the capability of dynamically picking various sets of elements for different beams. Projected apertures will be utilized to identify various sets of array elements available to form different individual beams, each pointing to a specific GPS satellite or a jammer. As to rejecting the jamming signals, elements with maximum base-line will be chosen to discriminate against jamming signals with the best nulling widths. Many predetermined receive beam positions/directions will be used to cover the hemisphere. Element weights for a nonplaner array for a given beam direction are opimized to maximize the peak gain through cross correlation techniques.