Abstract: A packaging system for field effect transistor ("FET") dies is described. Individual FET dies are eutectically bonded to individual FET mounting bars. The mounting bar/FET die combination is then eutectically bonded, along with the other components comprising the package, to a package base. After a wiring operation, the package is completed by sealing it with a cover. This packaging system has many fewer parts than known FET packages, permits the economical correction of micro-voids between the FET dies and the mounting bars, and is significantly less expensive than known FET packages.

Abstract: A dual input voltage controlled oscillator ("VCO") suitable for use in clock and data recovery ("CDR") systems operating at 100s to 1,000s of MB/sec is described. When a PLL using this VCO is locked onto a data stream of a fixed bit rate, the bang/bang frequency of the VCO does not vary due to process and temperature variation occuring either during manufacture or operation. The VCO is also relatively insensitive to supply voltage variations.

Abstract: A contact structure for a vertical cavity surface emitting laser is described. The contact structure comprises a surface metal contact, a degeneratively doped layer of low bandgap material less than 200 .ANG. thick, and a plurality of current spreading layers. The contact structure provides a low ohmic path between the metal contact and the active region of the vertical cavity surface emitting laser.

Abstract: A method and apparatus for determining the trailing bit position from a two operand addition is described. The determination of the trailing bit occurs in parallel with the addition. The two operands are encoded together and the encoded word used to determine the trailing bit position. As the operations of encoding the operands and operating upon the encoded operands require no more time than known methods to determine the trailing bit position after the addition is completed, and as the encoding and operating on the encoded words occurs in parallel with the addition operation, the present invention allows faster processing in the floating point unit.

Abstract: A microcomputer architecture and method allows for high processing speeds. A microprocessor constitutes the central processing unit. The microprocessor comprises an on-chip cache memory and is capable of reading data in a burst mode. The central processing unit and the system memory communicate by way of a high speed host bus. The system memory is comprised of multiple buses and is capable of delivering data to the microprocessor in a burst mode at high speeds. A memory controller addresses data locations within the system memory upon receipt of a first host address from the microprocessor. Accordingly, the microprocessor can access data in the system memory at an extremely fast rate when operating in a burst mode. High speed processing is accomplished without the need for an external cache.

Abstract: A method for fabricating transparent substrate vertical cavity surface emitting lasers ("VCSEL"s) using wafer bonding is described. The VCSELs have their active layers located much more closely to a heat sink than is possible in known absorbing substrate VCSELs. The improved heat transport from the active layer to the heat sink permits higher current operation with increased light output as a result of the lower thermal impedance of the system. Alternatively, the same light output can be obtained from the wafer bonded VCSEL at lower drive currents. Additional embodiments use wafer bonding to improve current crowding, current and/or optical confinement in a VCSEL and to integrate additional optoelectronic devices with the VCSEL.

Abstract: A method and apparatus for generating an AC voltage with user defined inductance and resistance values in series therewith is described. The output voltage of the AC source is sampled and a signal indicative of the total current being generated is derived. The signal is scaled to model a series resistance and scaled and differentiated to model a series inductance. The modelled series resistance and inductance are then combined with the output voltage. Different inductances and resistances can be modelled merely by changing the user's input to the microcontroller that controls the operation of the present invention.

Abstract: Arrays of vertical cavity surface emitting lasers ("VCSEL"s) used for illumination in both infra-red and visible light wavelengths are described. By using several different arrays, each array generating light of a different wavelength, a replacement for conventional lighting sources can be obtained. The present invention offers lower power consumption and longer operating lifetime than known lighting technologies.

Abstract: A relay for high frequency instruments and a reverse power protection circuit for high frequency instruments are described herein. The relay is inexpensive to construct, permits good impedance matching up to approximately 5 GHz, and can be easily mounted on a coplanar waveguide transmission line. The circuit can open the relay in response to a reverse power condition in as little as 8 microseconds and provides both good grounding and functions reliably up to 4 GHz.

Abstract: A method for forming an ohmic interface between unipolar (isotype) compound semiconductor wafers without a metallic interlayer and the semiconductor devices formed with these ohmic interfaces are disclosed. The ohmic interface is formed by simultaneously matching the crystallographic orientation of the wafer surfaces and the rotational alignment within the surfaces of the two wafers and then subjecting them to applied uniaxial pressure under high temperatures to form the bonded ohmic interface. Such an ohmic interface is required for the practical implementation of devices wherein electrical current is passed from one bonded wafer to another.

Abstract: A multilayer composite transducer is disclosed. The multilayer composite transducer comprises a plurality of layers wherein a piezoelectric material is dispersed periodically within a polymer matrix. The piezoelectric material is typically formed into columns or slabs, and these columns and slabs need to be aligned from one layer to the next. As this alignment can be difficult to perform, the present invention teaches a first method for fabricating the multilayer composite transducer which allows the alignment to be easily accomplished and a second and third method which reduce or eliminate the need for the alignment.

Abstract: A rate generator for use in a video server or other computer system requiring the generation of multiple timing signals from a single fixed frequency clock signal is disclosed. The rate generator stores a count value, a subtrahend value and a preload value for each timing signal that must be generated. The subtrahend value is subtracted from the count value. If this causes an underflow, an underflow signal, which comprises the generated timing signal, is asserted. The preload value is then added to the result of the subtraction, forming the new count value. If an underflow did not result from the subtraction, the result of the subtraction is the new count value. The frequency of the generated timing signal is determined by the ratio of the subtrahend and preload values. This permits the generation of many different timing signals from a single fixed frequency. The architecture required to perform these operations is relatively simple and inexpensive.

Abstract: A video server for providing Video-On-Demand is disclosed. A plurality of data sources are coupled individually to a first and second bi-directional data/instruction switch. The first switch is additionally coupled to a data storage system and the second switch is coupled to a network interface. A real time controller is coupled to the data sources and the switches and can couple any part of the data storage system to any selected data source and any given network channel to any selected data source. A control system coupled to the real time controller and the second switch provides support services to the real time controller and acts as a gateway to third party services and products. The data storage system is largely comprised of disk drive arrays. Video data is striped across the individual arrays, each video data program that a user requests being striped across one array. Each array provides video data to many users through the data sources.

Abstract: A digital loss-of-signal ("LOS") detector having a trough circuit and a smearing circuit is described. The trough circuit generates a logic output whenever an incoming communication signal is within a predefined voltage range. The output of the trough circuit is applied to the smearing circuit, which generates an LOS output whenever the output of the trough circuit remains at a predefined logic level for a predetermined length of time. In a second embodiment, a state machine is coupled to the output of the smearing circuit, the trough circuit, and a clock, the state machine generating the LOS indication if the output from the smearing circuit remains at the predetermined logic level for at least a predetermined number of clock cycles.

Abstract: A method and apparatus for correcting flow and pressure sensor drift in a gas chromatograph. At a convenient time when the chromatograph is not being used for analysis, the input valves controlling the input into the chromatograph are shut, reducing internal flow to zero. The indicated rate of flow is then measured using the flow sensor. If the value measured by the flow sensor during this test is different than the originally calibrated offset by some predetermined amount, then the newly measured value replaces the stored offset value. In a chromatograph where some minimum internal gas or liquid flow is necessary to prevent contamination of the instrument, a three-way valve can direct liquid or gas flow away from the flow sensor during this calibration run without eliminating internal flow through the chromatograph. To calibrate the pressure sensor, the pressure sensor is vented to ambient air pressure and its reading at that pressure is then used as an offset during later sample analysis.

Abstract: A method for using the same input/output pin on an integrated circuit ("IC") for both a high frequency AC signal and a DC signal simultaneously and a first circuit means to accomplish this multiplexing is disclosed. The circuit topology comprises a first and second capacitor, coupled between the AC signal input and the AC signal output. A first and second resistor are coupled to the same input/output pin as the capacitors but between the two capacitors and respectively to a DC signal input and DC signal output. The DC signal path thus lies between the two capacitors and sees them as open circuits, while the AC signal path sees the two resistors as open circuits and the capacitors as short circuits.

Abstract: A module comprised of a plurality of light emitting diode ("LED") lamps or other light emitting devices and a metal nesting frame with flexible joints between each row of LED bus bars is described. The flexible joint between the rows of LED bus bars allows the module to be assembled flat, which eases its manufacture. After the LED lamps or other light emitting devices have been mounted on the nesting frame, the flexible joints allow the module to be formed to fit within or on a complex three dimensional space. After forming, the metal nesting frame is still rigid enough to support the finished module in the desired shape.

Abstract: LEDs and other semiconductor devices fabricated with III-V materials and having exposed Al-bearing surfaces passivated with native oxides are disclosed. A known high temperature water vapor oxidation process is used to passivate the exposed layers of Al-bearing III-V semiconductor materials in confined-emission spot LEDs and other light emitting devices. These devices exhibit greatly improved wet, high temperature operating life, with little to no degradation in light output when exposed to such conditions.

Abstract: An integrated optical transceiver for optical serial communication is disclosed. The transceiver is formed as a single molded package incorporating an IC that forms part of the operating circuitry of the transceiver and the leadframe upon which the IC has been mounted. The necessary discrete components comprising at least an LED and photodiode coupled to both the IC and the leadframe. The leads of the leadframe can be formed in several different ways, which permits mounting the integrated transceiver in many different orientations. The integrated transceiver is more durable that transceivers realized using discrete components and provides users with unusual design flexibility, given the plurality of positions in which the transceiver can be mounted.

Abstract: A method of forming a light emitting diode (LED) includes providing a temporary growth substrate that is selected for compatibility with fabricating LED layers having desired mechanical characteristics. For example, lattice matching is an important consideration. LED layers are then grown on the temporary growth substrate. High crystal quality is thereby achieved, whereafter the temporary growth substrate can be removed. A second substrate is bonded to the LED layers utilizing a wafer bonding technique. The second substrate is selected for optical properties, rather than mechanical properties. Preferably, the second substrate is optically transparent and electrically conductive and the wafer bonding technique is carried out to achieve a low resistance interface between the second substrate and the LED layers. Wafer bonding can also be carried out to provide passivation or light-reflection or to define current flow.