Abstract: The safe-operating area (SOA) in a heterojunction bipolar transistor (HBT) is improved by providing a collector region in the transistor having a graded (uniformly or stepped) doping between the base region and the underlying subcollector region with the collector doping being lower near the base and higher near the subcollector and with the collector doping being less than the doping of the subcollector. The non-uniformly doped collector reduces Kirk effect induced breakdown when collector current increases.

Abstract: An electronic module includes an interconnect module having a plurality of metal layers separated by a plurality of dielectric layers in a stacked structure with electronic components mounted on one surface of the module. The electronic components are selectively interconnected by drilling via holes completely through all dielectric layers with a conductive material such as solder in each via contacting metal layers to be interconnected and each metal layer which is not connected by a via having a metal pattern devoid of metal at the via location. For via connecting non-ground layers, there will be a patch of solder mask on the backside ground layer to electrically prevent this via from inadvertently connecting to ground.

Abstract: An insulated trench isolation structure is formed by ion implanting impurities proximate to the trench edges for enhancing the oxidation rate and, hence, increasing the thickness of the oxide at the trench edges. Embodiments include ion implanting impurities prior to growing an oxide liner. The resulting thick oxide on the trench edges avoids overlap of a subsequently deposited polysilicon layer and breakdown problems attendant upon a thinned gate oxide at the trench edges.

Abstract: Waste toner is detected in a container of an image forming apparatus. An auger is provided within the container. A switch is provided which is operable depending upon a torque associated with operation of the auger. A frequency of activation of the switch is detected. A “not full”, “near full” and “full” condition of the waste toner in the container is determined depending upon the frequency of activation of the switch.

Abstract: A temperature compensating circuit for use with a current mirror circuit for maintaining a reference current value during temperature variations includes a compensating transistor connected in parallel with a reference current transistor and bias circuitry for biasing the compensating transistor whereby current flows from the reference node to ground through the compensating transistor to remove excess current from the reference transistor when temperature increases. A diode can be included in the bias circuitry for limiting bias current flow when the reference voltage drops below the voltage drop of the diode. An on/off switch circuit can be provided in parallel with the reference current transistor to further reduce reference current in specific applications.

Abstract: An end seal for use in an electrophotographic image forming apparatus uses an array of ridges (or grooves) to urge toner inwardly so as to help prevent toner escape. The end seal works in conjunction with a cleaning blade. The end seal includes a blade pocket for mating with the end portions of the cleaning blade and a middle portion having an array of ridges thereon. The ridges are angled inward to urge any toner trapped therebetween inward away from the end seals, where the toner can be directed to a waste reservoir in a normal fashion. This “snowplowing” action of the ridges helps prevent outward migration of toner, thereby minimizing toner escape. The end seal may be composed of two or more layers of differing materials. There may be an end seal at each end of the cleaner blade.

Abstract: A temperature compensating circuit for use with a current mirror circuit for maintaining a reference current value during temperature variations includes a compensating transistor connected in parallel with a reference current transistor and bias circuitry for biasing the compensating transistor whereby current flows from the reference node to ground through the compensating transistor to remove excess current from the reference transistor when temperature increases. A diode can be included in the bias circuitry for limiting bias current flow when the reference voltage drops below the voltage drop of the diode. An on/off switch circuit can be provided in parallel with the reference current transistor to further reduce reference current in specific applications.

Abstract: Waste toner is detected in a container of an image forming apparatus. An auger is provided within the container. A switch is provided which is operable depending upon a torque associated with operation of the auger. A frequency of activation of the switch is detected. A “not full”, “near full” and “full” condition of the waste toner in the container is determined depending upon the frequency of activation of the switch.

Abstract: A waste toner container and auger therefor. Auger flights have a continuously decreasing flight pitch from the front of the auger to the back of the auger. The auger includes a flightless portion near the back wall of the container.

Abstract: An end seal for use in an electrophotographic image forming apparatus uses an array of ridges (or grooves) to urge toner inwardly so as to help prevent toner escape. The end seal works in conjunction with a cleaning blade. The end seal includes a blade pocket for mating with the end portions of the cleaning blade and a middle portion having an array of ridges thereon. The ridges are angled inward to urge any toner trapped therebetween inward away from the end seals, where the toner can be directed to a waste reservoir in a normal fashion. This “snowplowing” action of the ridges helps prevent outward migration of toner, thereby minimizing toner escape. The end seal may be composed of two or more layers of differing materials. There may be an end seal at each end of the cleaner blade.

Abstract: Efficiency of an RF/microwave power amplifier is increased at a back-off power level by increasing the load resistance of the amplifier at the reduced output power level as compared to load impedance at a higher power level including full operating power. The different load impedances can be realized with two amplification units in parallel each having different load impedances. Alternatively, a single amplification path can be provided with an output impedance matching network which is selectively bypassed for increased impedance load during back-off power operation. In another embodiment, the output impedance matching network can include a shunt inductance which is selectively switched into the network to increase impedance for back-off power operation.

Abstract: An RF microwave power transistor has an input/output feed structure which functions as a low impedance microstrip line by providing a ground plane in close proximity to the feed structure on one surface of a semiconductor body. A second ground plane can be provided on an opposing surface of the semiconductor body with vias interconnecting the first and second ground planes. In addition to reducing feed impedance, a larger total transistor size can be provided before “odd mode oscillation” occurs.

Abstract: A toner cleaning apparatus for a printing device includes a toner separator operating against a component of the printing device, to dislodge toner particles therefrom. A toner receptacle is provided for collecting the dislodged toner particles, and an auger positively conveys the dislodged toner particles into the toner receptacle. A vibration plate is provided for receiving the toner particles dislodged by the toner separator, and for directing the dislodged toner particles to the auger. The vibration plate includes lengths thereof extending into the auger and deflected by the auger to induce vibrations along the plate and distribute-and convey toner particles disposed thereon.

Abstract: A waste toner container and auger therefor. Auger flights have a continuously decreasing flight pitch from the front of the auger to the back of the auger. The auger includes a flightless portion near the back wall of the container.

Abstract: An electronic module includes an interconnect module having a plurality of metal layers separated by a plurality of dielectric layers in a stacked structure with electronic components mounted on one surface of the module. The electronic components are selectively interconnected by drilling via holes completely through all dielectric layers with a conductive material such as solder in each via contacting metal layers to be interconnected and each metal layer which is not connected by a via having a metal pattern devoid of metal at the via location. For via connecting non-ground layers, there will be a patch of solder mask on the backside ground layer to electrically prevent this via from inadvertently connecting to ground.

Abstract: A hybrid microwave and millimeter wave integrated circuit (MMIC) RF power amplifier includes an integrated circuit in which an amplifier circuit is fabricated and an output impedance matching network comprising metal-insulator-metal (MIM) capacitors mounted on the integrated circuit chip with bonding wire inductors connecting the amplifier circuit with the capacitor elements. The resulting structure has a smaller form factor as compared to conventional power amplifiers employing planar transmission lines and surface mount technology capacitors.

Abstract: A hybrid microwave and millimeter wave integrated circuit (MMIC) RF power amplifier includes an integrated circuit in which an amplifier circuit is fabricated and an output impedance matching network comprising metal-insulator-metal (MIM) capacitors mounted on the integrated circuit chip with bonding wire inductors connecting the amplifier circuit with the capacitor elements. The resulting structure has a smaller form factor as compared to conventional power amplifiers employing planar transmission lines and surface mount technology capacitors.

Abstract: An insulated trench isolation structure with large and small trenches of differing widths is formed in a semiconductor substrate with improved planarity using a simplified reverse source/drain planarization mask. Embodiments include forming large trenches and refilling them with an insulating material which also covers the substrate surface, masking the areas above the large trenches, etching to remove substantially all of the insulating material on the substrate surface and polishing to planarize the insulating material above the large trenches. Small trenches and peripheral trenches surrounding the large trenches are then formed, refilled with insulating material, and planarized. Since the large trenches are formed prior to and separately from the small trenches, etching can be carried out after the formation of a relatively simple planarization mask over only the large trenches, and not the small trenches.

Abstract: High integrity cobalt silicide contacts are formed with shallow source/drain junctions. Embodiments include depositing a layer of cobalt on a substrate above intended source/drain regions, followed by silicidation and diffusing impurities from a doped film during or after silicidation in an environment which discourages out-diffusion of the impurities to the environment. The resulting source/drain junctions are self-aligned to the cobalt silicide/silicon substrate interface, thereby preventing junction leakage while advantageously enabling forming the cobalt silicide contacts at optimum thickness to avoid parasitic series resistances. The formation of self-aligned source/drain junctions to the cobalt silicide/silicon substrate interface facilitates reliable device scaling, while the avoidance of unwanted diffusion of impurities to the environment assures adequate doping of the source/drain regions.

Abstract: In an RF amplifier circuit having a plurality of transistor stages with each transistor having an input terminal for receiving an RF signal, a bias circuit is provided for applying a DC bias to the input terminal of a transistor. An isolation circuit connects a DC power supply to a bias circuit whereby DC voltage from the power terminal is applied to the bias circuit and RF signal from the transistor input terminal is attenuated. The isolation circuit includes a reactive serial path which allows the flow of DC current and presents an impedance to RF current flow and a reactive shunt path to ground which can comprise a capacitor or a serial inductor/capacitor circuit. The reactive serial path can comprise an inductor or an inductor/capacitor parallel circuit.