Reconfigurable Liquid Crystal Dielectric Image Line Leaky Wave Antenna at W-Band

This paper presents a reconfigurable dielectric image line leaky wave antenna at W-band. Reconfigurability is achieved by applying bias to anisotropic liquid crystal (LC) filled into the antenna. Instead of separating RF components and DC-bias network by complex or space consuming methods, the bias electrodes are simultaneously used as radiation elements. In order to evaluate this concept, a non-reconfigurable antenna with isolated unit cells is compared to a reconfigurable antenna, which has its unit cells connected by a metallic line. The non-reconfigurable demonstrator shows gain of up to
$\mathrm{18}$
dBi and can scan through broadside from −30
$\mathrm{^{\circ }}$
to +10
$\mathrm{^{\circ }}$
in the investigated frequency range from
$75 \,\mathrm{G}\mathrm{Hz}\,\mathrm{to}\, 102 \,\mathrm{G}\mathrm{Hz}$
. This frequency scanning sector can be shifted by
$10\mathrm{^{\circ }}$
when utilizing the reconfigurable LC antenna, while gain of up to
$15$
dBi is maintained. Since the bias electrodes are directly mounted on the image line, less than
$50 \,\mathrm{V}$
is necessary to control the LC. The antenna is comparably easy to fabricate, and only one bias voltage is directly related to a steering angle, which can be advantageous compared to complex phased arrays with multiple LC phase shifters.