MINIATURE PHASE-CORRECTED ANTENNAS FOR HIGH RESOLUTION FOCAL PLANE THz IMAGING ARRAYS

Abstract

An array of backward diodes of a cathode layer adjacent to a first side of a non-uniform doping profile and an Antimonide-based tunnel barrier layer adjacent to a second side of the spacer layer have a monolithically integrated antenna bonded to each backward diode. The Antimonide-based tunnel barrier may be doped with, for example, a non-uniform delta doping profile. An imaging / detection device includes a 2D focal plane array of an array of backward diodes, wherein each backward diode is monolithically bonded to an antenna, which array is located at the back of an extended hemispherical lens, and wherein certain of the arrays are tilted for correcting optics aberrations. The antennas may be a bow-tie antenna, a planar log-periodic antenna, a double-slot with microstrip feed antenna, a spiral antenna, a helical antenna, a ring antenna, a dielectric rod antenna, or a double slot antenna with co-planar waveguide feed antenna.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims benefit of provisional application Ser. No. 61 / 181,809 filed on May 28, 2009 and entitled “Miniature Phase-Corrected Antennas for High Resolution Focal Plane THz Imaging Arrays”, the disclosure of which is expressly incorporated herein by reference.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH[0002]Not applicable.BACKGROUND[0003]Non-ionizing and penetrative nature of terahertz (THz) radiation makes it promising for various detection methods in the commercial and defense industry [1-2]. Likewise, in the medical scene, particular bands in the THz frequency regime can be identified as markers of malignant tissues. Tuned to these marker frequencies, THz radiation recently has been proposed as an effective tool for cancer detection that will exhibit satisfactory resolution, substantial penetration depth, and non-harmful radiation properties in contrast to the x-ray technology. This is especially true and important fo...

AI Technical Summary

Problems solved by technology

However, long image acquisition times associated with such a raster scan constitute a major bottleneck.

Although these detectors are attractive in conjunction with the double slot antennas (because of their high Gaussian beam coupling efficiency and diffraction limited patterns [3]), the need for local oscillator signal and relatively large low-pass IF filter sections do not allow for tightly packed array development.(2) Large number of antenna / detector elements (or equivalently pixels) without resorting to expensive and bulky lenses.

When an extended hemispherical lens is used to focus the image on the array elements, reflections at the lens / air boundary significantly reduce coupling efficiency of the pixels positioned away from the lens axis.

Therefore, the number of detector elements is significantly limited by the lens diameter, and cannot support imaging for scan angles beyond ±20° [4].

Such doping may be a non-uniform delta doping profile.

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