Abstract: Synthesizer radiating systems provide efficient wideband operation with an antenna, such as a loop, which is small relative to operating wavelength. Energy dissipation is substantially reduced by cycling energy back and forth between a high-Q radiator and a storage capacitor. Wideband operation is achieved by actively controlling power switch devices. Dissipation is further reduced during high speed switching by use of sequential switching methods to avoid dissipation of energy capacitively stored in switch capacitances, including switch control circuit capacitance. Systems using multi-segment loop antennas are arranged to match antenna input impedance to switching circuit parameters. Personal transmit/receive systems mounted on a jacket or other clothing for field use are enabled.

Abstract: A dual-radiator whip antenna to operate over a 30 to 450 MHz frequency band includes a high frequency dipole above a low frequency monopole. The outer conductor (30) of a coaxial line is configured to operate as a monopole. Above the upper terminus of the outer conductor, an extension (32a) of the inner conductor (32) is configured as the upper arm of a dipole. An upper length of the outer conductor also functions as the lower dipole arm. With a single antenna port (13), a diplexer and other feed elements separate signals into high and low frequency bands respectively coupled to the dipole and monopole radiators. Increased high frequency range results from positioning of the center of radiation of the dipole above the monopole.

Abstract: A weather monitoring, measuring and reporting system which uses unattended, high-resolution digital cameras and laser rangers to both measure and display weather conditions in a local region, such as the region surrounding an airport. Visibility is estimated by processing images in the camera's field of view at known range distances. The light response of the camera is matched to the light response of the human eye. In a preferred embodiment of the invention, the camera generates a digital pixel image of range objects; that is, prominent terrain objects such as, buildings, water towers, etc. in the camera's field of view. The digital pixel values of these range objects are stored in system memory at known address locations. The contrast between an average background pixel value in a region adjacent to an object and the average object pixel value is used to determine if the object is visible.

Abstract: A self-contained four-dipole element provides a 360 degree phase-progressive-omnidirectional (PPO) circularly polarized antenna pattern. Via a single signal port, a PPO excitation network incorporated into the element excites the four dipoles at phases differing by successive 90 degree increments. The four-dipole element is adapted for efficiently reproducible fabrication using printed circuit techniques. Antennas employing a stack of the elements provide a hemispherical antenna pattern with PPO circular polarization and a sharp cutoff below horizontal. For GPS reception in Differential GPS aircraft landing applications, a 21 element antenna provides multipath suppression and a unitary phase center enabling avoidance of signal phase discrepancies. More or fewer elements may be employed in other applications.

Abstract: Low impedance loop antennas utilize a loop separated into a plurality of radiating segments fed in parallel. A four point feed loop antenna, including radiating segments 12, 13, 14, 15 had a measured input impedance varying from 1.8 to 5.8 Ohms over a range of 5 to 15 MHz, without excessive radiation Q degradation. An incorporated feed network includes transmission line segments, with conductors on opposite surfaces of a thin substrate, connecting the radiating segments to a centrally mounted coaxial connector for parallel excitation. Operating bandwidth of the loop antenna is determined by the characteristic impedance of the transmission line feed segments. Low impedance loop antennas which are small relative to operating wavelength can be fabricated on a thin flexible substrate for field transport and use. Incorporation of the antenna into a jacket or other clothing enables field use while minimizing restriction of activity of the user.

Abstract: UV sensing apparatus comprises a substantially light-proof housing (1), an aperture (1a) formed in the housing, a filter (2) positioned within the housing at the internal mouth of the aperture, a fluorescent member (3) positioned within the housing on that side of the filter remote from that adjacent to the aperture, and a light sensor (4) positioned within the housing to receive light emitted by the fluorescent member. The filter (2) is such that it substantially removes visible light, the fluorescent member (3) is such as to fluoresce when subjected to UV radiation, and the light sensor (4) is positioned so that substantially none of any electromagnetic radiation entering the housing (1) via the aperture (1a) impinges upon the light sensor.

Abstract: A test handler for picking up semiconductor devices from a conveying system and placing them at testing positions and returning the tested devices to the conveying system efficiently and modularly is shown. The basic apparatus has two concentric shafts each connected at one end to a cam following assembly and at the other end to a pick and place arm. The assembly has a block with a center bore for accommodating a ball screw and a longitudinal channel for receiving a lever cum cam follower subassembly connected to one end of the concentric shafts. The cam follower assembly and the concentric shafts translate the rotational movement of the ball screw into radial movement of the pick and place arms between the conveying system and the test rig. Another pick and insertion assembly associated detachably with the pick and place arms alternately picks up semiconductor devices from the conveying system and places them in position for testing.

Abstract: A method and process for the determination of presence and distribution of clouds is presented. The method involves the use of a sensor, such as laser ranger, for the collection of echo location measurement data from a three dimensional volume of the sky. The process involved in this invention utilizes the measurement data to evaluate and test for the presence of cloud banks. The process also utilizes the measurement data to quantitatively and qualitatively determine the cloud coverage amount and distribution. The preferred embodiment includes a laser ranger that samples the three dimensional volume at several azimuth-elevation angles through the application of a device capable of selecting azimuth-elevation angle values.

Abstract: A weather monitoring, measuring and reporting system which uses unattended, high-resolution digital cameras and laser rangers to both measure and display weather conditions in a local region, such as the region surrounding an airport. Visibility is estimated by processing images in the camera's field of view at known range distances. The light response of the camera is matched to the light response of the human eye. In a preferred embodiment of the invention, the camera generates a digital pixel image of range objects; that is, prominent terrain objects such as, buildings, water towers, etc. in the camera's field of view. The digital pixel values of these range objects are stored in system memory at known address locations. The contrast between an average background pixel value in a region adjacent to an object and the average object pixel value is used to determine if the object is visible.

Abstract: Double-tuned radiating elements 10 for cellular antennas are configured to enable stamping in one piece from flat sheet metal. Unitary construction incorporates a radiating section 22, an exciter section 14 and a balun section 12 in each radiating element. After the element is formed in one flat piece, a 90 degree bend is made along bend line BL to position radiating section 22 normal to the exciter and balun sections. When mounted in an antenna with the exciter and balun sections 14 and 12 parallel to a conductive ground plane surface, radiating section 22 extends forward normal to the ground plane surface. Radiating section 22 and exciter section 14 are fed by direct coupling to balun section 12, via shared current paths.

Abstract: A wedge device for a press for controllably exerting high amounts of force in a clamping operation during a semiconductor packaging process and for facilitating a linear force output in relation to its input. The wedge device is powered by a servo motor which is coupled to a planetary screw by a set of pulleys and a timing belt. The screw is mated with a nut which is prevented from rotating so that the rotation of the screw causes the nut to move in a linear direction. Metal extensions join the nut to a bottom wedge such that the wedge moves together with the nut. Slidably disposed on top of the bottom wedge is a block bearing firmly attached to a complementary wedge. The complementary wedge is free to move in a vertical direction but not in a horizontal direction. As the bottom wedge moves in a horizontal direction, the complementary wedge moves in a vertical direction. The complementary wedge is placed underneath a press to provide the clamping force necessary for a semiconductor packaging operation.

Abstract: An apparatus and method for reducing warpage in semiconductor packages, and in particular, thin quad flat packages (TQFPs). The apparatus includes a clamping jig having a bottom plate and an upper plate. The bottom plate is connected to a heater which heats the plate to approximately 50 to 70 degrees Celsius. An air supply controller delivers air supply to the upper plate. The TQFPs are placed in between the bottom plate and the upper plate immediately after they have been encapsulated with resin and the resin has cured. The clamping jig clamps the TQFPs in between the bottom and upper plate with a slight force. The TQFPs remain in the clamping jig until they have sufficiently cooled.

Abstract: A BGA mould assembly which can facilitate high degree of control over the clamping force on BGA substrates of varying thickness. An Independent drive is provided for each of the dual in-line cavity bars which clamp the BGA substrates. The drive mechanism is a wedge press which includes a servo motor, and a linear-conversion mechanism coupled to the servo motor to convert the rotation motion of the motor to a linear movement. An input wedge is coupled to the linear-conversion mechanism such that the input wedge moves correspondingly with the linear movement of the linear conversion mechanism. An output wedge is coupled to the cavity bar and positioned such that a horizontal movement by the input wedge causes the output wedge to move downwards. A roller cage is provided at the top and bottom of the input wedge to reduce friction.

Abstract: Without use of separate auxiliary antennas, adaptive nulling automatically reduces jamming or other interference affecting a radar or IFF system. A primary beam forming network utilizes four-port directional coupler devices, each having an ancillary port which would have been resistively terminated in the absence of the invention. Signals from ancillary ports are coupled to an auxiliary beam forming network to form auxiliary beam patterns which are orthogonal to and track steered main beam patterns. Auxiliary signals are received via the auxiliary beam patterns. Least mean square (LMS) control loops operate on a feedback basis to derive weighted auxiliary signals responsive to jamming signals. The weighted auxiliary signals are combined with the primary received signals (which may be sum and difference signals) in reverse polarity, so as to be additively destructive of the jamming signals. Multiple LMS control loops enable nulling of jamming signals simultaneously in sum and difference channels.

Abstract: A particular, appropriate BIOS extension image is selected from a potential set of multiple images for use in initializing a peripheral adapter. To enable proper selection, the peripheral adapter includes a firmware image of a BIOS extension that is storable on the peripheral adapter. The firmware image includes a nominal identifier of a BIOS extension and a set of one or more firmware markers that are compliant with the valid identification of the BIOS extension by a first predetermined host computer and that ensures that the firmware image is identifiable by a second predetermined host computer as being invalid. By specific selection of the firmware markers, these markers can be used to uniquely enable a predetermined one of the host processors to appropriately execute an appropriate BIOS extension image.

Abstract: U-dipole radiating elements (10) and associated feed conductors (20, 22) are cut or stamped from brass sheet stock. Each U-dipole (10) is then bent up at 90 degrees to the signal distribution conductor (22) which is supported in front of a reflector (12). The U-dipole element (10) includes a first dipole-type conductor segment (14) connected near one end to a feed segment (20) which is the sole signal feed path to the U-dipole element. A second dipole-type conductor segment (16), which is spaced from and parallel to and coextensive with first segment (14), is connected to the other end of the first segment (14). An antenna may include one or more individual U-dipole elements cut from sheet stock and connected to feed points. In a linear array antenna configuration, a group of U-dipole elements (10a-10b) and associated signal feed network components may be cut in a unitary form from a sheet of conductive material and supported in front of a reflector surface.

Abstract: In a cellular type communication system a sector antenna 12 provides coverage of a sector with a relatively low receive gain. A multi-beam antenna 20 covers the same sector with a plurality of narrower beams 21', 22', 23' and 24' providing higher gain. A multi-beam antenna system 10 provides higher gain operation by selecting the one of the narrower beams 21', 22', 23' or 24' currently providing best reception of a signal transmitted by a user and coupling that selected beam to a system receiver 18. Beam selection is accomplished by sequentially coupling each narrow beam to a microprocessor based control unit 40 and storing samples of user signals as received in each narrow beam on a continuing repetitive basis. The stored samples are then analyzed in order to select the beam currently providing best reception.

Abstract: Aircraft-mounted Identification Friend or Foe (IFF) antennas employ a linear array of radiator elements positioned transverse to the boresight axis. With an azimuth determination capability, but lacking elevation resolution, such antennas are subject to coning errors in determining the azimuth bearing of a target at an altitude differential. With use of a linear array (10) of multi-radiator elements (11, 12, 13), an output signal (23) having the characteristic of an amplitude which increases for off-boresight targets is provided. That signal is compared to a typical form of antenna system output signal (22), which has an amplitude which decreases for off-boresight targets. By such amplitude comparison, the angle (.beta.) to a target is determined and used to provide an azimuth correction factor (53). An apparent azimuth bearing (54) subject to coning error can then be corrected (55) to provide the true azimuth angle to a target (56).

Abstract: The present invention provides a method and apparatus for measuring transaction response times. The method and apparatus can identify service request sequences corresponding to a transaction and the start and stop times for the transaction. The invention can be applied non-intrusively/non-invasively to the service packets communicated between a source and destination node.

Abstract: A method of acquiring an ionizing radiation image including, irradiating a material with patterned ionizing radiation, exciting the irradiated material with excitation radiation to emit light in accordance with the pattern and acquiring the emitted light. The excitation radiation has a wave length which does not cause substantial electron-hole recombinations in said material. Preferably, the irradiation forms luminescent centers in the material and the excitation radiation has a wave length suited for excitation of the luminescent centers.