Reconfigurable microstrip antenna with tunable radiation beamwidth

This paper proposes a reconfigurable microstrip antenna with a tunable radiation beam. The design methodology uses two tunable size parasitic patches placed to the left and right of a probe-fed patch along its H-plane. Each parasitic patch is loaded with a lumped varactor as well as its biasing network, to effectively change its electrical size. Because the radiation beamwidth is controlled by the electrical size of the parasitic patches, electronic zooming is allowed by changing the capacitance value through the applied DC voltage. Both varactors are biased as unison, such that one DC control signal is required for the entire antenna. The antenna performance shows a dynamic control over the radiation beamwidth that ranges from 50° to 112° with capacitance tuning range of 0.5 pF to 2.5 pF.