Highly integrated VO2-based tunable antenna for millimeter-wave applications
Résumé
We report the concept of a frequency tunable antenna device operating in the millimeter wave
frequency domain. The ability of the antenna to switch between two frequency states is achieved
by the monolithic integration of a metal-insulator transition material (vanadium dioxide, VO2). The
VO2 material is an insulator at room temperature but can be driven in a high conductivity metallic
state when it is electrically activated using a continuous (DC) voltage. The antenna design is based
on a slot antenna excited by a microstrip line having a length that can be conveniently varied using
a VO2-based switch. Following the high-frequency VO2 material characterization, we present its
monolithic integration in the device prototype along with the comparison between the measured
and the simulated performances of the agile antenna. Thus, depending on the VO2 material state,
the antenna device can be conveniently switched between 33 and 37 GHz operating frequency
bands presenting stable radiation patterns with 5.28 dBi and 5.41 dBi maximum gains, respectively.