Theoretical and Experimental Investigations of Adaptive Reactance Parasitic Antenna Array

This work is dedicated to the low-cost beam steering antenna for long-distance WIFI applications. The design, prototyping and measuring of such antenna are described in this paper. Solution of three challenges from different sciences presented here: (1) from electrodynamics - designing of an adaptive parabolic reflector constructed from an array of passive scatterers with tunable reactive loads; (2) from algorithmization - developing of an optimizer that runs on the host computer or access point and adjusts the bias voltages on the loads to achieve the best received signal strength; and (3) from circuit design - implementing a minimal hardware controller with an interface to a daisy chain of digital-to-analog converters that generate varactor biases. Cited experimental measurements demonstrated that highly directional patterns can be realized while controlling orientation in azimuth and elevation. Initial results achieve 18 to 22 dBi of gain across an operational 40 degrees of azimuth.