Focal Plane Array of Shaped Quartz Lenses for Wide Field-of-view Sub-millimeter Imaging Systems
H. Zhang (TU Delft - Tera-Hertz Sensing)
Shahab Dabironezare (TU Delft - Tera-Hertz Sensing)
Jochem Baselmans (TU Delft - Tera-Hertz Sensing, SRON–Netherlands Institute for Space Research)
N Llombart (TU Delft - Tera-Hertz Sensing)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
Large format focal plane arrays (FPAs) of dielectric lenses are promising candidates for wide field-of-view submillimeter imagers. In this work, we optimize the scanning gain of such imagers via shaping lens surfaces. We develop an optimization procedure using a field correlation technique between the fields generated by a reflector on the top of the lenses and those generated by the lens feeds. Based on this procedure, an FPA of quartz lens antennas combined with leaky-wave feeds is designed to efficiently illuminate the reflector, achieving a directivity of 50.5 dBi up to scanning 20.3°. The obtained scanning gain loss of 2.6 dB is much lower than that associated with the direct fields coming from the reflector (about 6 dB). The proposed FPA is validated by full-wave simulations with excellent agreement. We have fabricated and measured an example shaped quartz lens optimized for the scanning angle of 20.3° at 180 GHz. The comparison between the simulations and the measurements also shows excellent agreement.