Polarization and Radiation Pattern Reconfigurability of a Planar Monopole-Fed Loop Antenna for GPS Application

Anotace: This paper presents a reconfigurable loop antenna with monopole-fed using embedded RF PIN switches based shorted parasitic elements for GPS applications. The antenna can independently reconfiguring multiple polarizations with switchable radiation pattern. Four switched metallic patches are used as parasitic elements to provide a reconfiguration capability to antenna acting as a driven monopole-fed loop. The edge of the parasitic elements is shorted by posts. The parasitic patches are connected/disconnected by using switching, therewith changing the configuration of monopole, to turn changes the current distribution over the loop surface. The antenna is designed to work on the GPS L1 frequency band. The antenna simultaneously changes the radiation beam in E- and H-planes, and switches among three polarizations (LP, LHCP, and RHCP) in the various modes. The antenna maximum gain among the different modes is tuned between 1.5 and 4.2 dBi.