Fresnel zone antenna for dual-band detection at millimeter and infrared wavelengths

In this work the concept of a Fresnel zone antenna for dual-band detection in the IR and millimeter wave region is presented. The design is based on a Fresnel zone plate lens in the IR that is transformed to serve as a millimeter-wave antenna. Two different designs are presented, a circular-zone design that gives a high diffractive efficiency in the IR and a square-zone design that gives a higher response in the millimeter band but a lower focusing efficiency in the IR. Both designs have an operation bandwidth with the same low frequency limit of 400 GHz (750 microm), which can be tailored by changing the number of Fresnel zones, and a high frequency limit of 4.5 THz (65 microm) for the circular-zone design and 5 THz (59 microm) for the square-zone design.