Abstract: A feed-forward microwave amplifier arrangement is disclosed havaing an error-detecting loop including a main amplifier branch and a phase-shift branch, as well as an error-canceling loop including an auxiliary amplifier branch and a phase-shift branch. A temperature compensating arrangement including a ferrite slab centrally mounted in a stepped rectangular waveguide is provided in the phase-shift branch of the error-canceling loop. The temperature compensating arrangement has a phase versus temperature characteristic similar to that of the auxiliary amplifier. An additional ferrite temperature compensating arrangement, having a phase versus temperature characteristic similar to that of the main amplifier, may be provided in the phase-shift branch of the error-detecting loop.

Abstract: The invention relates to an analog power amplifier (PA), particularly for a closed loop signal amplification requiring high output power, high efficiency, extremely high speed, wide operating temperature range and a low number of components. No thermal compensation, no transistor matching and no adjustments are necessary. Any power transistor switching is eliminated including a high efficiency operation with a multiple level power supply.The input signal of the PA is initially amplified in an input amplifier means which provides a pair of output signals. These signals are separately applied to the bases of a first and third transistors of even conductivity types. The emitter of the first transistor is coupled to the emitter of a second transistor of an opposite conductivity type. The collector, base and emitter respectively of the first, second and third transistors are separately coupled to voltage sources. A fourth transistor coupled in series with the emitter of the third transistor can be employed.

Abstract: In a single mode optical waveguide having a substrate, a cladding layer formed on the substrate, a core portion embedded in the cladding layer, and an elongated member for applying a stress to the core portion or a stress relief groove for relieving a stress from the core portion in the cladding layer along the core portion. The position, shape and material of the elongated member or the groove are determined in such a way that stress-induced birefringence produced in the core portion in accordance with a difference in thermal expansion coefficient between the substrate and the single mode optical waveguide is a desired value.

Abstract: A differential pair having a current source for providing amplification and slewing currents and a large signal circuit responsive to the differential pair input signals for shunting slewing current from the current source away from the differential pair for low input differential and linearly varying the amount of slewing current to be provided from the current source to the differential pair for higher input differentials.

Abstract: This invention relates to a connector for optical fiber used for optical communication parts, especially to a plug of the connector, comprising an inner tube into which an endportion of an optical fiber cord, whose cover is peeled off, is inserted and which is formed with axial slittings; and an outer tube being fitted onto the inner tube and made of a solid material, the inner tube being reduced in diameter at the portion having the slittings, thereby fixing the optical fiber thereto.

Abstract: In a filter arrangement having a transconductance circuit, a first capacitor is arranged between the inverting output and the non-inverting input of a balanced amplifier and a second capacitor is arranged between the non-inverting output and the inverting input. The outputs of a transconductance circuit (transconductor) are connected to the non-inverting input and the inverting input, which transconductor converts a balanced input voltage applied to the inputs into a balanced output current, its transconductance being variable by means of a variable current source. Further, the transconductor is loaded by a load circuit comprising a first current-source transistor and a second current-source transistor whose common base is connected, via a diode, to the junction point between two resistors arranged between the outputs of the transconductor.

Abstract: A noncontact measuring device has a generally L-shaped pivotable and rotatable probe means to be disposed along a straight portion of an object. Another noncontact measuring device has a rotatable probe means with an inverted L-shape to be disposed along a straight portion of an object. The probe of the former device projects a beam of light, while that of the latter device projects two beams of light. For either measuring device, when the beam or beams of light are being intercepted by the object, coordinates of a predetermined point of the probe means are read by a three-dimensional shape measuring apparatus to which the device is connected.

Abstract: A short circuit limiter having at least one current sink transistor connected to a trip point voltage setting resistor. The trip point voltage setting resistor receives a current which is a function of a reference current. One of the current sink transistors has a base connected above the tip point voltage setting resistor. The emitter of one of the current sink transistors sets the trip point voltage and is connected to the output transistors. If there is a short circuit in a load, the increased current will cause the voltage connection between the output transistors and the current sink transistors to rise up to the trip point voltage at which point, base drive current will be diverted away from the output transistors and through the current sink transistors.

Abstract: An ohmically isolated input circuit accepts a three pin connector of a cable from a signal source output for virtually all three pin connector standards, and will output a signal of the same voltage gain regardless of which of the three pin connector standards are used. The input circuit includes two magnetically isolated, serially connected transformers and three input terminals connected to the transformer's serially connected primary windings so that the input signal to any two of the three terminals is transformer coupled without change in gain to the circuit output through one or the other or both of the transformers depending on which two input terminals are selected. By using current transformers rather than voltage transformers the transformers run at very low signal levels thereby permitting the use of inexpensive and lightweight transformers without the introduction of distortion.

Abstract: A document size detecting apparatus for a copier and others is disclosed which is capable of identifying the size of a document by use of photosensors the numbers of which is smaller than that of the kinds of documents. A scanner is loaded with a pair of photosensors, or light-sensitive elements, which are spaced from each other in a direction perpendicular to a direction in which a scanner scans a document, the photosensors sensing light which is reflected by a document. A length of a document is determined based on a distance travelled by the scanner from a document scanning start position which is in turn calculated based on a light sensing condition of one of the photosensors, while a width of the document is determined based on a light sensing condition of the other photosensor.

Abstract: To increase a voltage gain of a differential circuit, constant current source type FETs in which a source and a gate are short circuited are used as a load element and as a current source. A constant voltage type FET is used as a clamp to clamp the load element. Therefore, a temperature characteristic and a deterioration of an AC characteristic, which cause problems in a conventional diode clamp type differential circuit, can be improved.

Abstract: The present invention relates to a disconnectable collimation assembly designed to transmit a light beam toward a device to be connected. The assembly comprises a base having a plane of reference strictly parallel to a plane of reference of the device to be connected, a sleeve mounted in the base and supporting a centering device holding a bar-lens, the lens being adjusted so that its optical axis will be in a predetermined position relative to the plane of reference.

Abstract: An optical isolator that includes a light emitter unit for converting an input electric signal to a corresponding light signal and a light detector unit for converting the light signal to a corresponding output electric signal, both units having a casing of the same diameter and a central port. The emitter unit is optically joined to the detector unit by a coupler formed of concentric layers of transparent dielectric material constituted by a core disposed within a cladding tube of the same length to define a light pipe and a sleeve surrounding the tube and projecting therefrom at either end to define input and output sockets to snugly receive the units with the ports thereof in juxtaposition to the opposite ends of the core. The core and the cladding tube of the light pipe have different indexes of refraction, whereby light from the emitter unit is propagated by multiple internal reflections to the detector unit.

Abstract: A method for detecting very small concentrations of gases in gas mixtures passed as a gas stream through a measuring cell having a chamber through which the gas stream flows through, a drift zone provided between an inlet and an outlet of the chamber, a gas stream ionizing radiation source located at the inlet of the drift zone, a collector electrode located at the outlet of the drift zone, a grid consisting of two groups of parallel wires located in the drift zone current adjacent grid wires are supplied with different electrical voltages and whereat an AC voltage of adjustable frequency is fed to the two groups of grid wires, and a measuring apparatus for detecting the collector current, including the steps of inducing the movement of the ions through the drift zone by means of a ventilator which generates a controlled gas flow to the collector electrode, periodically changing the frequency of the AC voltage applied to the groups of grid wires either continuously or stepwise, simultaneously measuring the co

Abstract: A linearized differential amplifier having two feedback paths. One of the feedback paths functions to linearize the output of the differential amplifier. The remaining feedback path functions to slightly limit the operating range of the differential amplifier to ensure the operational stability of the differential amplifier.

Abstract: A device is provided for amplifying and sampling multiplexed analog signals so as to give them an optimum level before digitization thereof. It includes several amplification and sampling assemblies with fixed gains differing from one to another, an amplifier whose gain is able to take on several predetermined values, connection means for selectively connecting one of the assemblies to said amplifier, comparison means comparing the amplitude of the signals at the output of the amplifier with threshold voltages and a selection member for choosing the assembly and the gain of the amplifier as a function of the comparison. In each of the assemblies, the amplification function is provided either by amplifier stages and/or by sample and hold units.

Abstract: Disclosed herein is a pusher device for a plastic optical fiber comprising a pair of pusher members for holding and fixing end portions of plural plastic optical fibers covered with sheaths, and a plurality of channel-like pushing portions provided on at least one of said pair of pusher members in such a manner as to correspond to said plural plastic optical fibers, said channel-like pushing portions having inner wall surfaces to be in press-contact with said sheaths. With this arrangement a contact area between the pusher members and the sheaths is increased to prevent slip of the optical fibers relative to the sheaths and maintain good light transmittance.

Abstract: An apparatus and method are disclosed for detecting the presence of particles on the surface of an object such as the front side of a patterned semiconductor wafer. A vertically expanded, horizontally scanning, beam of light is directed onto an area on the surface of the object at a grazing angle of incidence. A video camera positioned above the surface detects light scattered from any particles which may be present on the surface, but not specularly reflected light. The surface is angularly prepositioned (rotated) relative to the incident light beam so that the diffracted light from the surface and the pattern of lines on the surface is at a minimum. The object is then moved translationally to expose another area to the incident light beam so that the entire surface of the object or selected portions thereof can be examined, an area at a time.

Abstract: A single stage amplifying circuit defined by a bipolar transistor differential pair, supplied from a constant current regulator, and with balanced collector load resistors. One balanced output is connected directly to signal common and, also, the circuit is powered from a supply that is isolated or floating with respect to the signal voltage common, achieving low output voltage levels of either polarity with significantly low distortion levels.

Abstract: A temperature compensated amplifier network for a fiber optical receiver includes a photodiode having an optical input and a current output, and a cascadable transimpedance amplifier having N stages, each stage having a common base-emitter voltage. An emitter-follower transistor is coupled to the last stage of the transimpedance amplifier network and has a base-emitter voltage of the same magnitude but of opposite polarity from the base-emitter voltage of each of the amplifier stages. Any DC drift of the amplifier stages is therefore offset by a compensating drift in the opposite direction by the output emitter-follower.