A new technique for designing compact spatial feed networks for phased array antennas using antenna array sampling

A new technique of Array Probe Sampling with the purpose of designing ultra compact, near-field spatial feeds for use in antenna array systems is described in this dissertation. The new technique addresses gathering the detailed field information needed to design and optimize a near-field spatial feed network for a given array or sub-array. It uses the intended system antenna array as the probe for the near-field sampling as well as to optimize the spatial feed spacing and collector efficiency. Inherently, the technique connects the measurement to the end use environment of a spatial feed. This dissertation presents an evaluation and optimization of two specific near-field spatial feeds using this new array sampling technique. The work includes the full 3 dimensional electromagnetic modeling of the spatial feeds, the optimization of those spatial feed and finally the experimental testing and evaluation of the spatial feeds. The modeled versus measured data presented will show that near-field spatial feed design data can be accurately obtained analytically or empirically and the technique of Array Probe Sampling for compact spatial feed design is valid. The two spatial feed examples presented will show that optimal feed separations can have focal length to aperture diameter ratios (F/D) less than 1.0 and that very compact near-field spatial feed designs can be achieved.