Abstract: A system for retrieving and displaying a pictorial user interface on a computer display or other monitor whereby a series of time-lapse pictorial images change, over time, under software control such that the time of day and changes thereof can be visualized both for a user's geographical location or environment, as well as for the geographical location or environment of another person, such as a party telephoning the user from a different geographical location or environment in a different time zone.

Abstract: The present invention defines an anti-theft device for use with a variety of personal property, including bicycles, motorcycles and other small vehicles employing a three-part assembly of high-impact glass-filled nylon which attaches to vehicle frames of various size. The fastening means is hidden and sound channels are utilized to enhance an audible alarm and to prevent muffling of an interior speaker, activated by partial cutting or disconnection of a cable of known resistance. The cable is inserted in a case assembly with differing positions depending on whether the user wishes to set the alarm or store the cable out of the way if not energized. The alarm may be silenced by incrementally turning a key and removing a cable. The same key is positioned to allow arming of the alarm by insertion of the cables in the proper orientation.

Abstract: A videophone includes a video camera for transducing and digitizing images at a station and connected to a video processor for compressing and encoding the digitized images into video data. The videophone also includes an audio transducer and digitizer connected to an audio processor synchronized with the video processor for compressing and encoding digitized sound. The video and audio processors are connected to a communication controller for formatting and transmitting the video data bundled with the audio data via a standard bidirectional (full duplex) telephone line in the form of a twisted pair.

Abstract: An intelligent layout system for drawing objects and organizing the drawn objects. The layout system facilitates creation of objects, such as boxes that can contain text, graphics, outlines, titles, headlines, and other information and data, to provide a custom dashboard layout, as well as serves as a layout manager for organization of the objects. Additionally, the layout system enables objects to be manipulated individually or as a group and to be arranged permanently in various relationships, in which various components or attributes of the objects are interrelated. For example, the layout system enables a user to interrelate objects in one or more permanent relationships by selectively distributing, aligning, sizing, and/or spacing the objects. The layout system also provides a graphical user interface design tool for designing dynamic page layouts that automatically adapt to various page sizes and display screen sizes and resolutions.

Abstract: A computer based apparatus and method which provide access to complex technical information employed to maintain and repair complicated equipment, such as aircraft, to enable compliance with regulatory requirements.

Abstract: A modeling system for active semiconductor devices, such as gallium arsenide field effect transistors, for nonlinear (e.g., harmonic balance) circuit simulation. The model enables fast and unambiguous construction (model generation) by explicit calculations applied to raw device response data obtained using an adaptive, automated data acquisition system employed to characterize the device. The automated data acquisition system obtains the data adaptively, taking more data where nonlinearities are most severe and within a calculated, safe operating range of the device. The system converts conventional d.c. and S-parameter data directly into a detailed, device-specific, large-signal model. The system is extremely fast and replaces the need for conventional parameter extraction based on circuit simulation and optimization techniques.

Abstract: A routing barium-ferrite tuned resonator filter integrated with an image-enhanced, single-balanced mixer. The barium-ferrite tuned resonator filter is preferably a four-sphere barium-ferrite tuned preselector which is integrated with a harmonically mixed, image-enhanced, single-balanced mixer to provide a high level of dynamic range in a harmonically mixed front end. An input resonator of the preselector in combination with a dual PIN diode switch switches low-frequency input signals (e.g., 0 to 26.5 GHz) to a low-frequency output. For high-frequency input signals (e.g., 26.5 to 50 GHz), the four-sphere barium-ferrite tuned preselector is combined with the image-enhanced, single-balanced mixer which incorporates a GaAs monolithic diode bridge integrated circuit. This provides a front end component of a high-performance portable spectrum analyzer.

Abstract: A single sideband noise figure of a device under test is determined from double sideband measurements. A noise measurement system is provided, which includes a noise source, a mixer, a local oscillator, and a tunable intermediate frequency receiver. Three independent measurements are performed (one with the local oscillator frequency on the high side of the RF measurement frequency, another with the local oscillator frequency on the low side of the RF measurement frequency, and the third with the local oscillator frequency at the RF measurement frequency and the intermediate frequency at twice its former frequency). These noise power measurements are combined in such a way as to cancel the unwanted sidebands. Preferably, three output noise power measurements are also performed during a calibration so that the subsequent measurements are corrected for impedance mismatch errors.

Abstract: A data processing system for use in a measuring instrument having a keyboard with a plurality of numeric keys for entering numeric values and a plurality of terminator keys for indicating the completion of the entering of numeric values. Each of the terminator keys has associated therewith a pair of reciprocal exponents to indicate the weight to be applied to the numeric value. A processor is coupled to the terminator keys for automatically selecting one of the reciprocal exponents. That selection is deduced by the processor from the nature of the calculation.

Abstract: In a system for transmitting a digital signal over a signal path, such as a digital microwave radio, a method for finding worst case susceptibility of digital microwave radios to multipath fading. Signal notch depth at a given signal frequency is adjusted until a selected initial bit error rate occurs. Thereafter, the signal path is broken and then reestablished. If the measured bit error rate is greater than the initial bit error rate, the resulting bit error rate is measured, and the notch depth is decreased and then gradually increased, until the measured bit error rate is equal to or slightly exceeds the initial bit error rate. If the measured bit error rate is equal to the initial bit error rate, the signal path is broken and reestablished additional times until an accurate representation of worst case signal propagation is obtained. If the measured bit error rate is less than the initial bit error rate, the value of notch depth for the initial bit error rate is returned as the worst case value.

Abstract: A double-pass scanning monochromator for use in an optical spectrum analyzer includes an input optical fiber for emitting an input light beam, a diffraction grating for diffracting the input light beam to produce a spatially dispersed light beam, a slit for passing a selected portion of the dispersed light beam, a motor for rotating the diffraction grating, a shaft angle encoder for sensing grating position, and an output optical fiber. The light that passes through the slit is directed to the diffraction grating and is recombined by the diffraction grating to produce an output light beam. The light beam to be analyzed is incident on the diffraction grating during first and second passes. A polarization rotation device rotates the polarization components of the light beam by 90.degree. between the first and second passes so that the output of the monochromator is independent of the polarization of the input light beam.

Abstract: An analog ramp signal is used to control the frequency of a swept radio-frequency (RF) test oscillator. The analog ramp signal is generated by applying a fixed reference voltage to an analog integrator circuit. However, ramp accuracy is degraded by integrator gain error, drift, and nonlinearity. To correct for these errors, the analog ramp signal is periodically compared to a digital ramp signal generated by a digital-to-analog converter (DAC) during the course of a sweep. Preferably, the analog ramp signal is compared to the digital ramp signal many times during the course of the sweep. The difference between the two ramp signals is scaled and combined with the reference voltage to correct the slope of the analog ramp signal. An additional DAC preferably adjusts the gain of the feedback loop.

Abstract: A method for determining the amplified spontaneous emission noise of an optical circuit, such as an optical amplifier, in the presence of an optical signal includes applying a pulsed optical signal of prescribed intensity to an input of an optical circuit under test, and detecting an output signal from the optical circuit slightly after the pulsed optical signal is switched from on to off. The output signal immediately after the optical signal is switched off represents the amplified spontaneous emission noise of the optical circuit in the presence of an optical signal of the prescribed intensity. In a first embodiment, an optical spectrum analyzer is used for detecting the output signal. In a second embodiment, the output signal is passed through a narrow band optical filter to a photodetector. An electrical spectrum analyzer displays the detected waveform. When necessary, the observed output signal is extrapolated to a time immediately after the optical signal is switched off.

Abstract: A method to verify that a test and measurement system continues to operate within a predetermined acceptable range with respect to a given calibrated state previously defined for that system without the need for conventional external reference components. In accordance with one embodiment, performance verification of a network analyzer used to perform electrical measurements is achieved by storing RF "thru" measurement data (an RF thru measurement trace of the system) at the time of calibration at the factory or later repair and/or recalibration at a field service site. In accordance with another embodiment, performance verification of a lightwave component analyzer, used to perform electrical, electro-optical, opto-electrical, and optical measurements, is achieved by storing RF and optical thru measurement data (both an RF thru measurement trace of the system and an optical thru measurement trace of the system) at the time of calibration at the factory or later repair and/or recalibration.

Abstract: A tunable ferrimagnetic resonator circuit includes a fixed magnetic polepiece, a rotatable magnetic polepiece spaced from the fixed polepiece, an electromagnet for varying a magnetic field between the fixed and rotatable polepieces and a plurality of ferrimagnetic resonators connected in series and located in the magnetic field between the fixed and rotatable polepieces. The ferrimagnetic resonators include an initial resonator having an input port, a final resonator having an output port and one or more intermediate resonators. The rotatable polepiece preferably has a poleface having a first surface region that causes a constant magnetic field to be applied to the intermediate resonators as the polepiece is rotated, and second and third surface regions that cause variable magnetic fields to be applied to the initial and final resonators, respectively, as the polepiece is rotated. The polepiece is rotated to a position where each of the resonators is tuned to substantially the same resonance frequency.

Abstract: In a tunable ferrimagnetic resonator circuit, apparatus and method for tuning the circuit by manipulation of the position of the YIG spheres with respect to their associated coupling loops and the magnetic field. Each YIG sphere can be moved in three axial directions or rotated for alignment with the magnetic field while the circuit is under test, without the need for removal of any parts and without visual observation. Once the sphere has been positioned, it is automatically retained in that position without the need to be encapsulated in epoxy. The tuning process can be repeated or the circuit can be retuned at any time. The tuning apparatus can be coupled to external tooling which is manually manipulatable. Limits are included in the external tooling to prevent the spheres from touching other portions of the circuit.

Abstract: An optical coherence-domain reflectometry system provides an interferometer driven by a broadband incoherent light source with the device under test connected to one arm of the interferometer and a movable scanning mirror in the other arm providing a reference signal. The mirror moves at a controlled velocity to produce a Doppler shift in the reference signal frequency. The interference signal is detected and measured by a receiver. In the case where the receiver is a polarization diversity receiver, an intensity modulator and a polarization controller are incorporated into the reflectometer for use in calibrating the receiver. Calibration is also provided for a single photodetector receiver.

Abstract: A double pass scanning monochromator for use in an optical spectrum analyzer includes an input optical fiber for emitting an input light beam, a diffraction grating for diffracting the input light beam to produce a spatially dispersed light beam, a slit for passing a selected portion of the dispersed light beam, a motor for rotating the diffraction grating, a shaft angle encoder for sensing grating position, and an output optical fiber. The light that passes through the slit is directed to the diffraction grating and is recombined by the diffraction grating to produce an output light beam. The light beam to be analyzed is incident on the diffraction grating during first and second passes. A polarization rotation device rotates the polarization components of the light beam by 90.degree. between the first and second passes so that the output of the monochromator is independent of the polarization of the input light beam.

Abstract: An instrument includes a polarized optical source for producing three sequential predetermined states of polarization of a light beam at each of at least two wavelengths, as well as an optical polarization meter for measuring the polarization of a portion of the light beam at each wavelength transmitted by or reflected from an optical network by splitting it into four beams, passing three of the beams through optical elements, measuring the transmitted intensity of all four beams, and calculating Stokes parameters. The three sequential predetermined states of polarization at each wavelength yield three corresponding Jones input vectors at each wavelength, and the Stokes parameters for the responses of the optical network are converted to three Jones output vectors at each wavelength. A Jones matrix for the optical network to within a complex constant is then computed from the Jones input and output vectors at each wavelength.