Abstract: A transreflector is made by forming a series of spaced parallel stripes of a conductive material on one surface of a synthetic resin carrier film. The film is placed against the surface of a mold defining the desired concave internal curve for the transreflector, and the mold cavity is closed by placing over the film in spaced relationship a second mold half having the desired convex external curve for the transreflector. A fluid synthetic resin is introduced into the mold cavity to form the desired transreflector element with spaced parallel stripes disposed on the internal concave surface thereof. The carrier film is removed from the transreflector element with the conductive material stripes remaining on the transreflector element.

Abstract: An electromagnetic radiation reflection amplifier capable of amplifying cw or pulsed signals has a pair of cw oscillators operated under injection locking conditions. Diversion of oscillator power to a separate signal path during the off time of the input pulse is achieved through purely passive means; no active control devices are utilized. The device can be implemented for amplification of microwave, millimeter wave or optical signals. The amplifier comprises a 180-degree hybrid coupler, a matched pair of cw oscillator modules, a waveguide discontinuity, a waveguide termination, and an optional signal input element. For a magic-tee hybrid coupler, the cw oscillator modules are mounted on the ports of the symmetrically positioned waveguide arms and the waveguide discontinuity is located within either the sum arm or difference waveguide arm intermediate its ends.

Abstract: Compact microwave and millimeter wave radars operating at 77 Ghz and having resolution of no less than 3.2 meters at a distance of 100 meters. The exemplary dimensions of the radars are 145 millimeters in diameter and 100 or 85 millimeters long. The antenna of the radars employs folded optic design, with the actual focal length of the radar being less than that of the lens in the antenna alone.

Abstract: Compact microwave and millimeter wave radars operating at 77 GHz and having resolution of no less than 3.2 meters at a distance of 100 meters. The exemplary dimensions of the radars are 145 millimeters in diameter and 100 or 85 millimeters long. The antenna of the radars employs folded optic design, with the actual focal length of the radar being less than that of the lens in the antenna alone.

Abstract: A contraband detection system especially suited for detecting concealed non-metallic contraband such as ceramic or plastic weapons or illegal drugs carried by a person is disclosed. Plural sources of quasi-coherent millimeter wave radiation are disposed so as to uniformly illuminate a field of view. In the preferred embodiment, the radiation emitted by the sources is linearly polarized in a single plane such that the polarization of the radiation with respect to the plane in which linearly polarized radiation is preferentially received by the detectors can be controlled. For detection of dielectric objects, such as ceramic weapons or narcotics, these planes of polarization should be orthogonal to one another. The detector is a staring array which does not require scanning to generate an image of the entire field of view; the signal provided by each element of the detector array corresponds to the illumination reflected from objects in a single portion of the field of view.

Abstract: A millimeter wave imaging system is disclosed which has wide applicability throughout transportation and related industries. For example, the system may be used to provide an aircraft pilot with an image of a landing field which is essentially unaffected by fog, rain, snow, blowing sand, etc. The system comprises an array of imaging elements as its fundamental component. Each of the imaging elements of the basic array comprises an antenna consisting of a pair of conductive elements and a non-linear circuit element connected thereacross. A image can then be formed responsive to millimeter-wave radiation without complex processing steps or any form of mechanical or electronic scanning.To increase the sensitivity of the imaging array system, a local oscillator signal may be mixed with the energy received from the field of view in each of the imaging elements by the non-linear circuit element. The oscillator used to provide the local oscillator signal can also be used to illuminate the field of view.

Abstract: An apparatus for the selective transmission or reflection of incident electromagnetic radiation. The apparatus comprises a plurality of dielectric substrates combined so as to form a stack, wherein at least two of the substrates comprise conductive elements extending in first and second directions on a surface of the substrates and at least one of the substrates includes diodes which connect adjacent conductive elements in at least the first direction. The apparatus is electronically controllable between a reflection mode and a transmission mode, wherein in the reflection mode the diodes are reverse-biased and electromagnetic radiation incident on the apparatus is substantially reflected and in the transmission mode the diodes are forward-biased and incident electromagnetic radiation is substantially transmitted.

Abstract: An improved method for manufacturing a semiconductor device is described. In the preferred embodiment, a Gunn diode is manufactured from InP active and buffer layers. The buffer layer is deposited on a GaAs substrate using an epitaxial deposition process and the active layer is deposited onto the buffer layer. Electrical connection to the InP layers is made by etching a via through the GaAs substrate and metallizing the walls of the via. After the device has been placed in its final package, the GaAs substrate material is removed. As a result, good thermal and electrical contact is made to the InP active layer, and therefore, a Gunn diode manufactured according to this invention can reliably produced greater output power.

Abstract: A contraband detection system especially suited for detecting concealed non-metallic contraband such as ceramic or plastic weapons or illegal drugs carried by a person is disclosed. Plural sources of quasi-coherent millimeter wave radiation are disposed so as to uniformly illuminate a field of view. In the preferred embodiment, the radiation emitted by the sources is linearly polarized in a single plane such that the polarization of the radiation with respect to the plane in which linearly polarized radiation is preferentially received by the detectors can be controlled. For detection of dielectric objects, such as ceramic weapons or narcotics, these planes of polarization should be orthogonal to one another. The detector is a staring array which does not require scanning to generate an image of the entire field of view; the signal provided by each element of the detector array corresponds to the illumination reflected from objects in a single portion of the field of view.

Abstract: An improved millimeter imaging system is disclosed which generates high quality images from the field of view. Such system can be employed in a variety of application ranging from providing an aircraft pilot with an image of the landing field in fog, rain, snow, blowing sand, etc. to detection of concealed non-metallic contraband. The system elements, in which different elements detect signals from different portions of the field of view, so that images of the entire field of view are generated in real time, without using electrical or mechanical scanning. The outputs of the array elements are mapped to display pixels. The resolution of such images has previously been limited by the response characteristics of array elements to energy from only a portion of the corresponding field of view. One aspect of the invention is a significant improvement in image resolution.

Abstract: A system for landing aircraft during low visibility includes a number of millimeter wave sources in or near the runway light housings radiating millimeter wave beams along the runway. An airborne millimeter wave camera includes a millimeter wave lens that focuses the image of the millimeter wave sources upon a hemispherical detector array that provides signals processed to create an image of the millimeter wave sources corresponding substantially to the visible image perceived by a landing pilot when observing the runway light pattern during good visibility conditions.

Abstract: A millimeter wave sensing device is disclosed comprising a local oscillator source generating a millimeter wave signal which is mixed with millimeter wave radiation reflected from or emitted by objects in a field of view. The mixing is performed in a staring array of mixer/detector elements which need not be mechanically or electronically scanned to generate signals responsive to the entire field of view. In a first embodiment of the invention, the device detects millimeter wave radiation emitted by or reflected from the object to be imaged. In a second embodiment of the invention, the oscillator used to provide the local oscillator signal is also used to illuminate the field of view. In the second embodiment of the invention, the oscillator signal is preferably linearly polarized, and a polarizing grid is used to separate the local oscillator signal and illumination beam and direct them in a simple and efficient manner.

Abstract: A millimeter wave object detection and location system is disclosed comprising a source generating a millimeter wave signal which is divided into an illumination beam, directed onto a field of view, and a local oscillator portion, mixed with radiation reflected from objects in the field of view. The mixing is performed in a staring array of mixer/detector elements which need not be mechanically or electronically scanned to generate signals responsive to the entire field of view. The detected signal from each element is directly responsive to a portion of the field of view. The oscillator signal is preferably linearly polarized, and a polarizing grid is used to separate the local oscillator signal and illumination beam and direct them in a simple and efficient manner. A twist reflector may also be used to rotate the polarization of a portion of the beam to direct it onto the mixer/detector array for mixing with the received signal from the field of view.

Abstract: A Gunn diode oscillator tuning mechanism includes a waveguide wall formed with a cavity at the outside of the wall for accommodating a tuning mechanism. A tuning rod opening extends between the inside of the waveguide wall and the cavity to snugly accommodate a sapphire rod. A holder carries the fixed end of the sapphire rod and is slidable in the cavity. The holder is formed with a circumferential sectoral slot that engages an annular ring on the rotatable translatable shaft of a micrometer adjacent to the holder seated in a holding plate at the outside of the waveguide wall.