Abstract: Disclosed is a millimeter wave waveguide structure adapted for operation with negative resistance devices, such as solid state avalanche breakdown diodes, at frequencies up to about 170 GHz or higher. A central portion of the structure is formed by a cylindrical metallic impedance transformer and bias pin which has a major face thereof substantially parallel to a common lower waveguide wall of the structure. A negative resistance device is DC coupled between this common waveguide wall and one edge of the impedance transformer, so that the impedance transformer also provides the required DC bias to the negative resistance device. Other portions of the waveguide structure include a first upper waveguide wall, immediately adjacent one side of the impedance transformer, and this wall, together with the common lower waveguide wall, forms a tuning cavity into which a sliding tuning short is positioned.

Abstract: An improved gaming token and fabrication process therefor wherein an injection molding compound is applied at selected preconfigured locations within and between a pair of aligned, substantially flat annular non-metallic rings. The common interface between the injected molding compound and the annular rings receiving the molding compound is seen as continuous sharply defined lines between the different colors of the molding compound and of the rings, respectively. These lines define preconfigured surface designs which are contiguous with the outer surfaces of the two annular rings.One or more coins may be mounted in a central opening defined by certain portions of the annular rings, and these coins impart an added measure of control over the distribution of these tokens in instances where the annular rings are made by authorized outside vendors.

Abstract: Disclosed is a novel photoconductive array suitable for use as an infrared detector, and a novel process for fabricating same. In this process, a chosen metallization pattern is disposited on the surface of an insulating substrate, and thereafter the metallization pattern is either covered or partially covered with a layer of selected photoconductive material, such as lead selenide or lead sulfide. The photoconductive material is formed into a predetermined pattern which is accomplished using conventional photoetch techniques. Then, a suitable photoresist mask is deposited at a selected location on the surface of the photoconductive layer in preparation for an electroplating step. In this electroplating step, a surface contact metallization for the photoconductor is plated on both the previously deposited photoconductive and metal surfaces which are not masked by the photoresist.

Abstract: An intrusion system detects changes in background radiation received from a plurality of orthogonally arranged fields of view (FOV) which preferably are defined by thin polyhedrons coextensive with the walls of the room. These fields of view are generated by a plurality of orthogonally arranged optical reflectors located in certain corners of the room, and any changes in background radiation within these fields of view are detected by one or more thermopile detectors which are optically aligned with the above optical reflectors. The low level - low frequency output signal voltages form the thermopile detectors are converted to an AC signal and amplified for use as an intrusion alarm signal.

Abstract: Disclosed is microwave oscillator or amplifier circuitry which is tunable over a wide bandwidth and which includes an improved variable loading on a negative resistance semiconductor diode, such as an IMPATT diode. This loading is provided in mutually perpendicular directions closely adjacent the diode. In one direction, a DC bias connection is mounted together with an adjustable coaxial filter thereon, and this filter serves as a series tuning element for the diode. A movable short is mounted for adjustment in a direction perpendicular to that of the above coaxial filter and provides parallel tuning for the diode. These series and parallel tuning elements are operative to match the real and imaginary components of the diode impedance to the real and imaginary components of the load impedance, respectively, at a particular operating frequency, thereby maximizing the power transfer and the DC to RF conversion efficiency of the circuitry.

Abstract: Disclosed is a fire and explosion detection system wherein long wavelength radiant energy responsive signals are processed in one channel and compared to short wavelength radiant energy responsive signals which are processed in a second channel. When these signals are coincident in response to a fire or explosion of a predetermined threshold magnitude, an output fire suppression signal is generated.

Abstract: Disclosed is a microwave power accumulator including a plurality of coaxial oscillator circuits, each tightly coupled to a single common output combining resonant cavity. Each of the coaxial circuits includes a negative resistance diode at one end and a lossy terminating (microwave absorbing) material at the other end which absorbs and suppresses resonant modes within each coaxial circuit. This feature enables the cavity resonance of the common output combining cavity to dominate all of the individual coaxial circuits spaced therearound. The spacing of these coaxial circuit modules around a common cylindrical output combining cavity permits a high packing density and good individual heat sinking for the accumulator.