Abstract: By adding light reflective and/or transparent and/or translucent material within a micro-electronic circuit housing, improved light transfer is achieved between a light generation source and a light utilization device. In one embodiment, the reflective material is placed on the inside surface of a non-metallic housing lid and the light from the light source (typically an LED) reflects from the reflective material and impacts the device (typically an FET). In another embodiment, the LED and FET are encased in a clear (low light-loss) material (typically silicone overcoat) so as to allow the light from the LED to reflect from the top of the clear material onto the FET. If desired, an opaque encapsulant surrounds the clear material and fills out the volume within the housing.

Abstract: Hermeticity of microcircuit packages is achieved in one embodiment by recognition that water can penetrate the ceramic structure and thus the ceramic structure is sealed and the edges of the ceramic package are metallically bonded to the electronic package. In one embodiment, a clear ceramic dielectric compound is sprayed on the ceramic and then the package is glazed.

Abstract: A radio frequency power splitter/combiner employs a multilayer printed circuit board (PCB). A first power splitter/combiner section is formed on a first layer of the multilayer PCB and has signal propagation traces coupling a first major port to a first pair of minor ports. A second power splitter/combiner section is formed on a second layer of the multilayer PCB and has signal propagation traces coupling a second major port to a second pair of minor ports. At least one signal ground is formed on one or more layers of the multilayer PCB intermediate the first layer and the second layer. The at least one signal ground isolates the first power splitter/combiner section from the second power splitter/combiner section.

Abstract: A portable calibration unit for calibrating test equipment is disclosed that may incorporate a communication interface for connecting to a computer embedded within the test equipment, a variable signal source for producing a test signal, a processor in communication with the computer for controlling the variable signal source, and a test interface for communicating the test signal to the test equipment.

Abstract: A four-channel multifunction digital frequency synthesizer which uses direct numerical synthesis to generate one or more complex output signals having selectable frequency, phase offset, amplitude level and waveform is provided. A waveform synthesizer digitally synthesizes precise sine, square, triangle, ramp, uniform and Gaussian noise and DC waveforms which can be selected for any of the four channels. One of the four channels can be frequency, phase and amplitude modulated by the signals on the remaining three channels in any combination. The four channels are time-multiplexed which allows the use of a single frequency synthesizer to realize four independent channels and a large number of support functions and capabilities in a high-density VLSI integrated circuit on a single chip. The synthesizer system can provide up to four independent output signals which can be any one of the four channel signals, or any combination of the four channel signals summed to form a complex waveform signal.

Abstract: A low distortion differential sampler circuit implemented in GaAs is provided. The sampler circuit constitutes an on/off switching circuit rather than a sample and hold circuit. Elimination of the holding capacitor results in shorter switching times and reduced error. The sampler implements a differential, balanced architecture which compensates for clock signal feed through. The sampler circuit includes a three-stage, AC coupled GaAs pre-amplifier which provides a complementary clock signal to drive the sampler and sets the DC levels.

Abstract: A frequency synthesizing apparatus of the closed-loop design employing a first frequency mixing means to provide a continuous constant increment frequency coverage over a given output signal frequency range. The first frequency mixing means is responsive to the output signal and a first reference signal to provide a first difference signal both when the output signal frequency is higher than and lower than the first reference signal frequency. A frequency comparison means is responsive to the first difference signal and to an input signal, the input signal being continuously variable over a given input frequency range, to provide a first error signal for controlling the output frequency and stabilizing the closed loop. The first reference signal is comprising of a plurality of predetermined, selectable frequencies provided by a phase-locked loop employing a second frequency mixing means.