Abstract:
A heat-sink assembly is configured with two parts to grip a light-emitting element and produce a transverse force urging a surface of the light-emitting element toward a surface of the heat-sink assembly, which conducts heat away from the light-emitting element. Fastening mechanisms and a fulcrum inter-connect the heat-sink parts and produce the force that grips the light-emitting element. A configuration of the heat-sink parts creates a semi-enclosed space accessible through a gap. A configuration of elastomeric gaskets within the semi-enclosed space protects a portion of the space from intrusion of liquids or other environmental influences. Configuration of the heat-sink parts to form a recess in the heat-sink assembly provides protection of the light-emitting element from mechanical damage, and the recess may contain transparent materials that further protect the light-emitting element from detrimental environmental influences.
Abstract:
An example of a circuit structure may include a first dielectric layer having first and second surfaces, and a channel extending at least partially between the first and second surfaces and along a length of the first dielectric layer. First and second conductive layers may be disposed on respective portions of the first and second surfaces. A first conductor, having an end, may be disposed on a surface of the first dielectric layer, including at least a first portion extending around at least a portion of the conductor end. The second conductive layer may line the channel extending around a portion of the conductor end. Some examples may include a stripline having a second conductor connected to the first conductor. Some examples may include a cover having a wall positioned on the first dielectric over the second conductor.
Abstract:
A protective coating useful as a passivation layer for semiconductor devices incorporates a thin film of an amorphous diamond-like carbon. In one implementation, a thin film of amorphous silicon is deposited over the carbon material. The semiconductive passivation coating prevents electrical shorts, dissipates charge build-up and protects against chemical contamination.
Abstract:
A rectangular pulse generator system is operatively configured to generate a generator output signal, the generator output signal formed as a base rectangular waveform gated by a modulating rectangular waveform, the base rectangular waveform having a first frequency and the modulating rectangular waveform having a second frequency less than the first frequency. A low-pass filter coupled to the rectangular pulse generator system is configured to receive a filter input signal representative of the generator output signal and to produce a filter output signal representative of the filter input signal. A voltage-controlled current source coupled to the low-pass filter generates a drive signal conducted by at least one LED producing a light flux determined by the current level of the LED drive signal. Methods are devised for calibration and for setting the average light flux level.
Abstract:
A digital-unit interface comprises a first node, a second node, a third node, and an amplifier assembly. The first node is connected to a pull-up resistor and is configured to be connected to the signal line of a transmission line connected to a first digital unit at a distal point. The second node is configured to be connected to a second reference electrical potential, a signal-return line of the transmission line, and a signal-return line of a second digital unit. The third node is configured to be connected to a signal line of the second digital unit. The amplifier assembly is configured to be connected between the first node and the third node and to transform between high electrical potentials on the first node and lower electrical potentials on the third node while the second digital unit communicates with the first digital unit.
Abstract:
Two or three conductor coplanar transmission lines and lossy coplanar resistive films are formed on a surface of a substrate. The resistive film dimensions and resistivity are selected to suppress various spurious electromagnetic modes within and around the substrate. The resistive films may be positioned along the outer edges of the transmission lines or between the transmission line conductors. The resistive film may have regular spaced openings for producing an average resistivity different than that of a continuous resistive film. In one embodiment, a signal conductor has a serpentine shape and resistive film elements are positioned between adjacent sections of the signal conductor. In another embodiment, interdigitated resistive film elements extend between transmission line conductors.
Abstract:
One embodiment of a process in accordance with our invention includes the step of forming a P type region on a semiconductor substrate. After the P type region is formed, an N type layer is epitaxially grown on the P type region. A Schottky gate is then formed on the N type epitaxial layer. A first portion of the epitaxial layer serves as a transistor source, a second portion of the epitaxial layer serves as the transistor drain, and a third portion of the epitaxial layer serves as the channel. Of importance, the P type semiconductor region helps prevent various short channel effects caused when current carriers flowing between the source and drain flow too far from the Schottky gate.
Abstract:
A multiplexer circuit may include a first-frequency-quarter-wavelength transmission line extending between a junction between a common terminal and a second-frequency terminal, and a first-frequency low-impedance circuit electrically directly connecting the first transmission line to a circuit ground. In some examples, a second-frequency-quarter-wavelength transmission line may extend between the first transmission line and a third-frequency terminal. A second-frequency low-impedance circuit may electrically directly connect the second transmission line to the circuit ground. The first and second transmission lines and the first and second low-impedance circuits may provide a third-frequency transmission line. A further second-frequency low-impedance circuit may electrically couple the second terminal to the first transmission line. A third-frequency low-impedance circuit may electrically couple the second terminal to the circuit ground. The first-frequency, further second-frequency, and third-frequency low-impedance circuits and the first transmission line may provide in combination a second-frequency transmission line.
Abstract:
A circuit structure may be formed in a substrate having a face and an open trench, where one or more chips are to be mounted. At least one bridge may extend across an intermediate portion of the trench, and optionally, may divide the trench into sections. A conductive adhesive layer may be applied to the substrate face and, if included, the bridge. One or more circuit chips may be mounted on the adhesive layer, with at least one edge of one circuit chip adjacent to the trench. Alternatively or additionally, an adhesive layer may be applied to a base of a chip and then mounted to the substrate face, in like fashion. The trench may accommodate excess adhesive flowing out from under the one or more chips, while the bridge retains the adhesive across the width of the trench. If the adhesive is conductive, this provides continuity of the conductive layer on the face of the substrate across the trench. In one example, pairs of circuit chips may be effectively mounted in adjacent relationship for interconnection without interference from excess adhesive.
Abstract:
A coupler may include four ports, and first and second sets of conductive strips. Each set of conductive strips may include a plurality of interconnected conductive strips connected between two ports. Each conductive strip of the first set may be electromagnetically coupled to a conductive strip of the second set. Conductive tabs capacitively coupled directly or indirectly to the ground conductor may extend from conductive strips of the first and second sets. An interconnection may be positioned between adjacent tabs, the interconnection connecting conductive strips of one of the sets of conductive strips. The adjacent tabs may be spaced different distances from the interconnection.