Abstract: A time interval measuring apparatus is provided for measuring the time interval between two signals. The two signals are successively brought to synchronization by delaying one of the two signals as they pass through a series of time shift cells connected in tandem. These delays are accumulated in a register, and the total net delay which is required to bring the two signals into synchronization is indicative of the time interval between the two signals. This indication of the time interval between the two signals thus forms the time interval measurement thereof. It can be refined by increasing the number of time shift cells in tandem and using progressively finer delays.

Abstract: By using a multiplying digital-to-analog converter for signal demodulation in the disclosed detection scheme, the demodulating signal from the local oscillator can be in digital form without seriously affecting the detected, or demodulated, output. Specifically, a multiplying digital-to-analog converter (DAC) is used for detection. The multiplying DAC accepts an analog input for demodulation or detection and a signal in the form of a repeating string of digital values as the demodulating input. Sensitive, and therefore inherently unstable, filters generally required in the prior art to prefilter the demodulating signal to reduce undesirable higher harmonics are therefore not required, thus reducing one major source of instability in a detection system.

Abstract: A technique of patterning a conductive layer for interconnections in integrated circuits is disclosed. The technique enables fine line conductors to be fabricated. In accordance with the invention, a pattern for the conductors is etched into the surface of a substrate through the use of a patterned photoresist layer. The conductive layer is then deposited over the photoresist layer and into the pattern etched into the substrate surface. In intervening steps, only the portions of the conductive layer outside the depression of the pattern in the surface are removed; the portions of the conductive layer within the depression remains intact to provide the pattern of fine line conductors desired.

Abstract: Output signals from a set of Faraday loops located in a common plane are combined selectively to simulate the output signals from a set of mutually orthogonal antennas. This arrangement and use of Faraday loops are especially suitable in a hospital environment for monitoring patients. Because of the availability of output signals from a set of equivalent orthogonal antennas, any danger of a gap in the monitoring of the patient is greatly minimized; the patient can be monitored regardless of the changing orientation of the patient with regards to the monitoring antennas.

Abstract: A method of making improved step metal coverage of semiconductor device using enhanced reflow of phosphosilicate glass by ion implantation of arsenic at low temperature is provided. In one embodiment, the fabrication processing includes implanting arsenic into the phosphosilicate glass and reflowing the ion implanted phosphosilicate glass by heating the phosphosilicate glass to smooth the phosphosiliate glass for allowing a metal interconnection.

Abstract: A simple resonant cavity for sustaining magnetostatic waves (MSW) in a resonator device is achieved by depositing a ferrimagnetic film on a substrate and cutting two substantially parallel edges in the film. The substantially parallel edges serve as simple reflectors to replace the complex reflector arrays that are etched or otherwise formed in the prior art thin film resonators.

Abstract: A method of sampling accurately the instantaneous content of a high speed counter without interrupting the counting process is provided. The method is applicable even when the higher order digits of the counter are constructed by slower switching circuits configured in either a synchronous or ripple-through arrangement. The switching and carry propagation times of these higher order counters need not be shorter than the time between successive events being counted. Sampling of the contents may be made repeatedly in the interim without affecting the totality of the final count.

Abstract: By providing a current splitter stage and a feedback loop to current and voltage gain stages of an amplifier, a preamplifier can be implemented as an integrated circuit. This integrated preamplifier is particularly suited in bar code reader systems and fiber optic receiver systems.

Abstract: The acoustic imaging transducer described herein incorporates an acoustic stack contained in an alumina housing which also provides structure for electrically connecting the transducer array elements to system signal processing electronics.

Abstract: A sine wave generator uses a phase-to-amplitude converter (PAC) which functions with a novel multiplier. By using pipelined adders, intermediate amplitude and slope data from storage are combined to get an output amplitude which is equivalent to that from a prior art multiplier but without the objectionable through-put delays inherent in prior art multiplier PAC's.

Abstract: A housing for interfacing a fiber optic cable with a semiconductor device allows simple insertion and removal of the cable by application of an axial force. The housing exerts a spring-like gripping force upon the cable and axially aligns the cable to the semiconductor device in order to minimize loss of transmitted light. A portion of the gripping force is translated into an axial force by a slanted ridge within the housing which acts upon a ridge on the cable to cause the cable to be forcefully abutted to the semiconductor device.

Abstract: A novel signal synthesizer provides high frequency synthesized waveforms for the user. By converting phase information into digital outputs in parallel and by selectively coupling these digital outputs, an ordered digital output is formed to provide the high frequency waveforms. This ordered digital output, which represents points on a sine function, is converted to an analog signal for the synthesizer output. Furthermore, frequency and phase modulations of the synthesized waveforms are easily implemented with this novel signal synthesizer; the modulation information is simply added to the digital outputs prior to selectively coupling. Thus when the ordered digital output is converted to an analog signal, the analog signal contains the modulation information.

Abstract: The present invention provides a circuit for second correlated sampling. By switchably connecting feedback in the circuit, the stage providing the second correlated sampling is precharged independent of an external reference voltage source to make the circuit simpler and hence integratable.

Abstract: A ventilator which accommodates to a patient's efforts in breathing and to his change in respiratory requirements is provided by a system with a novel control law. The novel control law determines a target ideal pressure-volume wave-form which characterizes the patient's respiratory requirements; this waveform is constantly modified and corrected during the course of ventilator operation to enable the patient to breathe with minimum ventilation opposition, or fighting.

Abstract: A programmable logic array is provided by symmetrically arraying drivers around the periphery of a substrate. These drivers are essentially OR/NOR gates having latched complementary outputs. The latched complementary outputs enable these logic gates to be implemented into flip-flop elements, and the complementary outputs allow these logic gates to be implemented into AND logic gates. Selectable feedback paths are also provided to add greater flexibility to the programmable logic array. Altogether, the symmetrical logic array provides a simple one-to-one representation of most logic designs to form a universal logic design board in the form of a random logic or programmable state machine.

Abstract: A method is provided which minimizes the risetime of a pulse modulated microwave signal propagated through a frequency multiplier circuit which has an input blocking capacitor. The circuit is conditioned by injecting a pulse which charges the blocking capacitor to its steady state value. When a subsequent pulse modulated microwave signal is sent through the frequency multiplier circuit, there is no delay in risetime associated with charging the blocking capacitor of the frequency multiplier circuit.

Abstract: A frequency converter for a complex digital input provides a shift of frequency without the necessity of time-consuming and expensive numerical multiplication. Furthermore, by combining the conversion process with digital filtering, the frequency of the converted output can be halved. The output can be resampled and reapplied to the novel converter for repeated shifts in frequency and reduction of bandwidth in the case of down-conversion.

Abstract: An optical switch having low insertion loss and low crosstalk is provided by two slabs of birefringent material having a polarization rotator as a control element interposed therebetween. By controlling the polarization rotator electrically, a selectable ratio of transmitted-to-displaced output optical power is realized. The optical switch therefore can function as an attenuator to a light beam traversing through it. In the preferred embodiment calcite crystals are used for the slabs, and a liquid crystal cell for the polarization rotator.

Abstract: An apparatus is disclosed for determining the impedance and dissipation factor of a capacitive and/or inductive device and to reduce measurement error by digital calculation and manipulation. A synchronous rectifying means, a phase shifter and a detecting means are employed to detect the in-phase and orthogonal components of the current through a device and to compare it to a reference voltage impressed across the device. An arithmetical calculation using the values of these components determines the impedance and the dissipation factor of the device.

Abstract: The retainer sleeve of a three piece ferrule suitable for very small diameter optical fibers has an outside diameter threaded portion at the closed end so that, after the ferrule and optical fiber have been assembled, an outer sleeve, having a correspondingly threaded inside diameter, can be used to adjust the optical fiber end to be positioned flush with the end face of the ferrule during assembly. The design of the outside threaded sleeve for retaining the connector of two fibers to be connected is improved by inserting a shim sleeve of molded, pliable material having a "D"-shaped inside diameter to apply force to the outside diameter of the ferrules when inserted therein for reliable, concentric snug-fit.