A compact W‐band quasi‐optical detector packaged by meta‐surface reflector and 3D‐printed lens

This article presents a compact W‐band quasi‐optical detector that can be easily extended into an array for focal plane imaging applications. The quasi‐optical detector consists of an antenna‐coupled detector packaged by a low‐profile meta‐surface reflector and a 3D‐printed lens. The antenna‐coupled detector with a GaAs Schottky diode is printed on a low‐cost and low‐loss laminate. To extract the detected low‐frequency signal within a small footprint, a pair of vertical metallic posts instead of conventional planar strips is designed and loaded at the ends of the antenna. For facilitating unidirectional radiation patterns, a low‐profile meta‐surface reflector with a thickness of λg/8 is placed under the antenna‐coupled detector. In addition, a 3D‐printed dielectric lens is loaded upon the antenna‐coupled detector, which can enhance the radiation gain by 6 dB. Both the meta‐surface reflector and the 3D‐printed lens are fixed by an asymmetric H‐shaped framework, forming a low‐cost and lightweight package for the detector. Based on the proposed detector, a W‐band 1 × 16 array is experimentally demonstrated, exhibiting a responsivity of 100 V/W~410 V/W from 92 to 110 GHz. The total size of the array is only 27 λ × 4 λ × 1.8 λ, where λ is the free space wavelength at the center frequency.