Westinghouse Electric Corporation

Richard J Ravas

Harvey C Nathanson

Leonard C Vercellotti

Alan F Mandel

Marvin Cohn

John C Schlotterer

James A Neuner

James P McHugh

Edward C Niehenke

Raymond G Seidensticker

Andress Kernick

George V Hall

Manvel A Geyer

Frank L Przywarty

Lynd R McCormick

The invention provides frequency multiplier circuitry which may be used in the output section of high power microwave systems to efficiently provide higher output frequencies. Generally, one multiplier stage may be utilized to double the frequency of the input signal with several stages being cascaded to achieve even higher frequencies. The varactor diodes utilized in circuits of the invention are preferably constructed primarily of silicon carbide, which has many advantages when compared with current varactors constructed of GaAs or silicon. Some presently preferred embodiments utilize a four terminal varactor bridge instead of a single varactor diode. The invention also teaches several significant techniques for improving the bandwidth of the circuitry, thus allowing variation of the frequency of the input signal without significantly attenuating the output signal.

Wideband frequency multiplier having a silicon carbide varactor for use

Push-pull complimentary MOSFET devices are formed in a thin active layer between the top surface of a high resistivity silicon wafer and a insulating layer implanted below the top surface. Each MOSFET is composed of a plurality of cells each having a source, a gate, and a drain region extending fully through the active layer. Grooves extending through the wafer are lined with vias which connect the source regions with a floating ground plane on the bottom of the wafer. The gates of all the cells are connected by a gate bus on the top surface. Air bridges spanning the gates and the source vias connect the drain conductors of each cell. Neutralizing capacitors connected between an input and an opposite output of the push-pull complimentary MOSFET devices match the parasitic capacitances of the devices and provide wide bandwidth amplification with roll off well into the GHz range without the need for tuning inductors.

Broadband microwave integrated circuit amplifier with capacitive

A dual mode electronic identification system using a tag which has a RF receiver and transmitter contained therein. In the first mode the tag responds to an interrogation signal by transmitting identification data to the interrogator. In the second mode the tag periodically transmits an identification beacon signal to a directional sensing antenna which uses the signal to compute the position of the tag. The power supply for the tag operates from an internal battery or from power received from a portal signal via a tag receiving antenna. The battery can be automatically turned off when the tag is in the portal area and the unit can be shifted into the battery operated beacon mode when the tag is removed from the portal area.

Dual mode electronic identification system

A melt replenishment system for dendritic web growth having a pellet feed arrangement, which distributes equal amounts of feed material to a pair of feed tubes in communication with opposite ends of a crucible to maintain a melt pool at a constant level and a cover gas system, which keeps the feed tubes flowing and helps maintain thermal consistency within the melt.

Melt replenishment system for dendritic web growth

An elevator system including an elevator car to be stopped at a predetermined stopping point from any initial speed below a predetermined maximum value, at a predetermined uniform rate of deceleration. The uniform rate of deceleration determines the desired speed versus distance-to-go reference pattern, which is initiated at a predetermined fixed distance from the stopping point. If the car speed is at the maximum value, deceleration will be initiated immediately. If the car speed is below the maximum value, the car is allowed to continue at the same speed until the car speed and location of the car relative to the stopping point match a point on the reference pattern. This point is accurately determined via digital feedback and comparison circuits which start the elevator car on the desired deceleration speed pattern with zero error. When the point on the reference pattern is reached, digital control circuitry including an up-down counter provides an error count for an actuator which controls the deceleration of the car to closely follow the reference pattern.

Elevator system

A DC pulse generator, specifically suitable for application as a cardiac pacemaker having a substantially constant energy output which is independent of the output load. The output pulse is derived from a capacitive reactance which is partially discharged to a preselected reference level. The cyclic rate of discharge is maintained substantially constant, and accordingly, the pulse width is varied to assure a constant energy output to the load. The capacitive reactance is charged in between output pulse periods from a matched impedance radioisotope thermoelectric source through a constant current inverter, step-up transformer, voltage doubler, inverter network. The oscillator controlling cyclic discharge of the capacitance through the load and the inverter, which is arranged in a push-pull configuration, is designed to be self-starting to avoid stall conditions during operation. Furthermore, the discharge rate is substantially independent of the DC level and provides a negative rectangular output pulse. In the event external defibrillator pulses are applied, means are provided to conduct resulting current impulses directly into the capacitive reactance which can safely absorb the energy, thus avoiding failures in the internal circuitry elements.

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Penn Twp., Westmoreland County, PA, United States of America

Richard J Ravas