Abstract: This disclosure describes a semiconductor device that can be used as a mixer at RF frequencies extending from a few tens of GHz into the THz frequency range. The device is composed of narrow bandgap semiconductors grown by solid source molecular beam epitaxy. The device can comprise a GaSb substrate, a AlSb layer on the GaSb substrate, a In0.69Al0.31As0.41Sb0.59 layer, on the AlSb layer and wherein the In0.69Al0.31As0.41Sb0.59 comprises varying levels of Te doping, a In0.27Ga0.73Sb layer on the In0.69Al0.31As0.41 Sb0.59 layer, wherein the In0.27Ga0.73Sb layer is Be doped, wherein the first section of the In0.69Al0.31As0.41Sb0.59 layer has is Te doped, wherein the second section of the In0.69Al0.31As0.41Sb0.59 layer has a grade in Te concentration, and wherein the third section of the In0.69Al0.31As0.41Sb0.59 layer is Te doped.

Abstract: This disclosure describes a semiconductor device that can be used as a mixer at RF frequencies extending from a few tens of GHz into the THz frequency range. The device is composed of narrow bandgap semiconductors grown by solid source molecular beam epitaxy. The device can comprise a GaSb substrate, a AlSb layer on the GaSb substrate, a In0.69Al0.31As0.41Sb0.59 layer, on the AlSb layer and wherein the In0.69Al0.31As0.41Sb0.59 comprises varying levels of Te doping, a In0.27Ga0.73Sb layer on the In0.69Al0.31As0.41 Sb0.59 layer, wherein the In0.27Ga0.73Sb layer is Be doped, wherein the first section of the In0.69Al0.31As0.41Sb0.59 layer has is Te doped, wherein the second section of the In0.69Al0.31As0.41Sb0.59 layer has a grade in Te concentration, and wherein the third section of the In0.69Al0.31As0.41Sb0.59 layer is Te doped.

Abstract: Highly sensitive infrared detectors can be made from superconducting micrrip transmission lines, having a single ground plane, a dielectric substrate on the ground plane, and a thin film path of superconducting oxide on the substrate. These microstrip transmission lines can be fabricated into resonant or non-resonant structures. The detectors operate by detecting changes in a microwave signal transmitted through the microstrip, measures in the amplitude, frequency or time domains. An embodiment of this invention is an asymmetric ring interferometer, with or without a metal segment in the shorter leg of the interferometer. Another embodiment of this invention is a meander path transmission line, which, in certain configurations, may be used as a single element array with very high resolution in the direction parallel to the meander lines.

Abstract: A microwave switch is provided for controlling the transmission of microw energy in a microstrip transmission line structure. The microwave switch comprises an electrically conducting ground plane in contact with one side of an undoped semiconductor material having on its other side a superlattice of gallium arsenide consisting of a periodic sequence of p- and n-doped gallium arsenide layers. P- and n-type regions are formed integral with and electrically connected to the superlattice, and first and second microstrip transmission lines are electrically connected to respective ones of the n- and p-type regions.