摘要:
A method and apparatus for optically clocked optoelectronic track and hold (“OCOETH”) device. The OCOETH device includes a diode bridge, input node, at least two current sources and at least two photodetectors. The input node is operatively coupled to the diode bridge and can receive an analog input signal. The at least two current sources are operatively coupled to the diode bridge and can forward bias the diode bridge. The at least two photodetectors are operatively coupled to the diode bridge and can receive an optical input clocking signal, and can reverse bias and forward bias the diode bridge in response to the optical input clocking signal. The hold capacitor is operatively coupled to the diode bridge and can track the analog input signal when the diode bridge is forward biased, and can hold the analog input signal when the diode bridge switches from forward biased to reverse biased.
摘要:
A synthetic diamond wafer grown by deposition from a plasma has a smooth, substrate side face and a rough, deposition side face. The rough face is coated with a bonding agent which fills the valleys and is finished so that its surface is parallel to the substrate side face to permit photolithographic processing of the wafer. Also disclosed is a multi-wafer laminate of two or more diamond film layers bonded together with an interlayer. Smooth, flat outer faces of the layers are oriented mutually parallel. The inner, bonded faces may be rough. A filler of diamond particles in the bonding agent improves the thermal conductivity of the laminate.
摘要:
A synthetic diamond wafer grown by deposition from a plasma has a smooth, substrate side face and a rough, deposition side face. The rough face is coated with a bonding agent which fills the valleys and is finished so that its surface is parallel to the substrate side face to permit photolithographic processing of the wafer. Also disclosed is a multi-wafer laminate of two or more diamond film layers bonded together with an interlayer. Smooth, flat outer faces of the layers are oriented mutually parallel. The inner, bonded faces may be rough. A filler of diamond particles in the bonding agent improves the thermal conductivity of the laminate.
摘要:
A narrow-band, inverted homo-heterojunction avalanche photodiode, configured in the shape of a mesa situated upon a substrate which is transparent to selected light energy wavelengths. The diode is inverted for operation such that the incoming light energy enters the substrate side, passes through a wavelength selective buffer layer and is absorbed upon entering the succeeding, active region. Avalanche gain is attained by drift from the area of absorption to the high field p-n homo-heterojunction located immediately thereafter. The device exhibits low levels of noise during operation because absorption is occurring in a low field region and because the ionization and breakdown noise associated with lattice mismatches is avoided through the formation of the p-n homo-heterojunction in one continuous growth process. Appropriate passivation of the mesa walls inhibits surface leakage and breakdown effects.
摘要:
A preamp for coupling to an avalanche photodiode (APD) of an optical receiver has an input stage including a dual gate field effect transistor (FET) and a single gate FET coupled in a cascade arrangement. The dual gate FET has its first gate coupled to the output of the APD, its second gate and source grounded, and its drain driving the gate of the single gate FET in a cascade arrangement. The source of the single gate FET is level-shifted and coupled by means of a feedback resistor to the first gate of the dual gate FET to provide a negative feedback. The output stage is a third FET with its gate coupled through a blocking capacitor to the source of the single gate FET in the input stage and with its drain providing the output of the preamp. In a preferred embodiment, the FETs used are GaAs FETs (GAASFETs).
摘要:
Power semiconductor switching devices, power converters, integrated circuit assemblies, integrated circuitry, power current switching methods, methods of forming a power semiconductor switching device, power conversion methods, power semiconductor switching device packaging methods, and methods of forming a power transistor are described. One exemplary aspect provides a power semiconductor device including a semiconductive substrate having a surface; and a power transistor having a planar configuration and comprising a plurality of electrically coupled sources and a plurality of electrically coupled drains formed using the semiconductive substrate and adjacent the surface.
摘要:
Power semiconductor switching devices, power converters, integrated circuit assemblies, integrated circuitry, power current switching methods, methods of forming a power semiconductor switching device, power conversion methods, power semiconductor switching device packaging methods, and methods of forming a power transistor are described. One exemplary aspect provides a power semiconductor device including a semiconductive substrate having a surface; and a power transistor having a planar configuration and comprising a plurality of electrically coupled sources and a plurality of electrically coupled drains formed using the semiconductive substrate and adjacent the surface.
摘要:
Active compensation techniques are used for control of temperature, wavelength, and other characteristics of lasers within a laser array. The laser array includes a plurality of lasers and a plurality of dissipation elements. The dissipation elements can be interstitial to the lasers and can be implemented as non-lasing diodes. The dissipation elements are selectively activated (i.e., turned “on” to dissipate power) to adjust the temperature at the laser junctions. The change in junction temperature allows the lasers to operate at their specified wavelengths. The dissipation elements can be individually controlled and two or more bits of resolution can be provided. Active compensation can be used to adjust (i.e., to compensate) the temperature of selected lasers when one or more lasers are deselected. Active compensation can also be used to adjust (i.e., “tweak”) the wavelengths of the lasers within the laser array to be within their specified wavelengths.
摘要:
Disclosed is a logic circuit with a plurality of AND logic elements, each including a plurality of Schottky diodes with each cathode connected to a logic input and the anodes connected in common to establish an AND output. A diode pull up FET is provided for each AND output, with the source connected to the AND output, the gate connected to the source, and the drain connected to a source of positive bias potential. An OR logic element includes a plurality of Schottky diodes with each anode connected to one of the AND outputs and the cathodes connected in common to establish an OR output, while a diode pull down FET has its drain connected to the OR output, with the gate connected to the source and the source connected to a source of negative bias potential. A level shifting diode is placed between the OR output and the pull down FET. An output FET is connected through its gate to the drain of the diode pull down FET, with the source connected to ground and the drain providing a logic output from the circuit. An output pull up FET has its source connected to the drain of the output FET, the gate connected to the source, and the drain connected to the source of positive bias potential.
摘要:
The invention relates to methods and devices for precise geolocation of low-power, broadband, amplitude-modulated rf and microwave signals having poor coherency. The invention provides a basis for dramatic improvements in RF receiver technology, offering much higher sensitivity, very strong rejection of unintended signals, and novel direction finding techniques. When mounted on an airborne surveillance platform, the invention can detect and geolocate weak, broadband, incoherent RF and/or microwave signals. Embodiments of the invention are implemented by dual channel receivers (heterodyne or tuned-RF) that use crystal detection and Fast Fourier Transform (FFT) analysis for geolocation. Geolocation is accomplished using a subsystem of phased arrays and an angle of arrival technique.