A low profile electronically-steerable artificial-impedance-surface antenna

A Ku-band, electronically-steerable, artificial-impedance-surface antenna (AISA) was designed, fabricated and measured. It is capable of scanning in elevation from -70° to 80° with gain variation of less than 5 dB. The antenna operates by launching a surface wave along a surface-wave waveguide (SWG) whose impedance elements are rectangular patches with electrically tunable capacitors between them. The radiation beam is scanned in elevation by applying voltages to the varactors to change the SWG's impedance pattern. Azimuthal scanning can be accomplished with a linear array of SWGs whose relative radiation phases are controlled with variations in the impedance patterns.