Design of beam-steerable parasitic patch arrays using variable reactive loads

The design of patch-type Electronically Steerable Parasitic Array Radiator (ESPAR) that is capable of steering its main beam along either Ä-plane or E-plane with satisfactorily low side-lobe level (SLL) is presented. The continuous beam-steering along both principle planes is realized through adjusting the reactive loads of the associated passive patch elements. The analytic formula for the resultant steering direction is given. The steerable angular range of the prototype designs is up to ±30° and ±20°, respectively. Several design considerations and issues encountered are discussed as well.