Aperture-Coupled Liquid Metal Tunable Dipole

A frequency-tunable planar antenna that uses parallel, variable-length, liquid-metal dipole filaments is presented. The liquid-metal dipoles are contained in thin cavities embedded in a silicon-based polymer and are aperture-coupled by a feed structure beneath. A prototype of the antenna with nominal frequency of 3.5 GHz is fabricated and measured to demonstrate 730 MHz of continuous tuning with a peak realized gain of 4.50 dBi and back radiation below −3.93 dBi. The antenna is constructed on a 40mm x 50mm Rogers 5880 (∊r = 2.2, tanδ == 0.0009) laminate sheet with thickness 0.51 mm.