Scanning mircostrip arrays using controlled mutual reactance with parasitic elements

We investigate a linear array of microstrip patches consisting of excited elements spaced >λ with two parasitic patches in between. Varactor-controlled reactances are used to terminate the parasitic elements, to provide variable coupling between patches and to vary the reactive part of the input impedance of excited elements. A full wave analysis model is used to obtain the impedance matrix of the system. Subsequently a genetic algorithm optimization is used to obtain the reactance terminations to scan over an angular range of 0 to 45° in the H-plane. This low cost array can adaptively reconfigure for arbitrary shaped beams, and has the ability to steer a null.