Abstract: A horn antenna including first and second substrates having at least one first and at least one second horn shaped cavity formed in the first and second substrates, respectively. The horn shaped cavities taper from a narrow end and have a longitudinal axis along a plane parallel to a top surface of the first and second substrates. The second horn shaped cavity is disposed opposite the first horn shaped cavity and is a mirror image of the first horn shaped cavity. Internal surfaces of the first and second horn shaped cavities include a metalization layer. The horn antenna is fabricated by forming at least one mask having a longitudinally extending mask opening on the first and second substrates and preferentially etching the first and second substrate through the mask opening to form the first and second horn shaped cavities.

Abstract: A millimeter or submillimeter wavelength device including a substrate having a horn shaped cavity, and first and second extension layers formed on a top surface of the substrate adjacent to the horn shaped cavity. The first and second extension layers define additional opposed sides of the horn shaped cavity, channels, and walls of the waveguide. Internal surfaces of the horn shaped cavity, the channels, and the waveguide walls include a conductive layer. Two such structures, which are mirror images of each other, are joined to form a horn antenna with integrated channels and a waveguide. The device is fabricated by forming a resist layer on a substrate which includes a horn shaped cavity. The resist layer is etched to form a half horn antenna, channels and walls of a waveguide. Internal surfaces of the half horn antenna, the channels, and the walls of the waveguide are then metalized. Two such metalized structures are then joined to form a full horn antenna integrated with channels and a waveguide.

Abstract: A millimeter or submillimeter wavelength device including a substrate (2) having a horn shaped cavity (18), and first and second extension layers formed on a top surface of the substrate adjacent to the horn shaped cavity. The first and second extension layers define additional opposed sides of the horn shaped cavity, channels, and walls of the waveguide. Internal surfaces of the horn shaped cavity, the channels, and the waveguide walls include a conductive layer. Two such structures, which are mirror images of each other, are joined to form a horn antenna with integrated channels and a waveguide. The device is fabricated by forming a resist layer on a substrate which includes a horn shaped cavity. The resist layer is etched to form a half horn antenna, channels and walls of a waveguide. Internal surfaces of the half horn antenna, the channels, and the walls of the waveguide are then metalized. Two such metalized structures are then joined to form a full horn antenna integrated with channels and a waveguide.

Abstract: A high speed, metal-semiconductor-metal photodetector includes a pair of generally circular, electrically conductive electrodes formed on an optically active semiconductor layer. Various embodiments of the invention include a spiral, intercoiled electrode geometry and an electrode geometry having substantially circular, concentric electrodes which are interposed. These electrode geometries result in photodetectors with lower capacitances, dark currents and lower inductance which reduces the ringing seen in the optical pulse response.

Abstract: A Schottky diode for millimeter and submillimeter wave applications is comprised of a multi-layered structure including active layers of gallium arsenide on a semi-insulating gallium arsenide substrate with first and second insulating layers of silicon dioxide on the active layers of gallium arsenide. An ohmic contact pad lays on the silicon dioxide layers. An anode is formed in a window which is in and through the silicon dioxide layers. An elongated contact finger extends from the pad to the anode and a trench, preferably a transverse channel or trench of predetermined width, is formed in the active layers of the diode structure under the contact finger. The channel extends through the active layers to or substantially to the interface of the semi-insulating gallium arsenide substrate and the adjacent gallium arsenide layer which constitutes a buffer layer.