Abstract: An injection laser is turned on and off in response to DATA and DATA control signals. A photodiode is irradiated by the laser and passes current that is proportional to the intensity of the laser radiation. A current switch responds to the DATA signal to define a current path for the source current of associated source current transistors when the laser is on. A difference current, corresponding to the difference between the photodiode current and the source current, is then applied to an integrator. The integrator generates an error signal corresponding to the difference in charge transfer between the photodiode and the source current transistors. The error signal is applied to operate a bias transistor that generates a corresponding DC bias current for the laser.
Abstract: A flexible, modular communications processor is disclosed comprised of a plurality of microprocessors. A demand assigned bus is provided to couple the microprocessors through an arbitrator to an information storage and retrieval device. Each of the microprocessors comprises a conventional integrated circuit microprocessor, associated local memory, transmitters and receivers for coupling information to and from the bus and bus access circuitry, cooperating with the arbitrator to allocate the bus resource. Communication input/output is handled by a plurality of microprocessors configured as line processors, each coupled to its associated interface switch, which, in turn, is coupled to modems or other input/output devices. A background or executive microprocessor is included to manage system configuration and react to failures.
Type:
Grant
Filed:
June 4, 1980
Date of Patent:
December 7, 1982
Assignee:
M/A-COM DDC, Inc.
Inventors:
Pradeep Kaul, Daniel Wendling, Harold Ford, Deepak Muzamder, Christopher Newport
Abstract: The microwave system is employed for the detection of cancerous tumors and is particularly effective in the early detection of such tumors. The system is of the dual type, combining in a single unit a passive radiometer with an active microwave transmitter. The sensitive passive microwave radiometer is adapted to sense subsurface temperatures, coupled with a solid state microwave transmitter for providing localized heating of the subsurface tissue, thereby taking advantage of the differential heating due to vascular insufficiency associated with the thermal characteristics of tumors, thus highlighting and enhancing early detection of cancer. The radiometer frequency is preferably higher than the microwave heating frequency with the microwave radiometer operating in C band and the transmitter in L band. An applicator forms the means by which the system couples to the radiating or emitting surface including a simple TE.sub.1-0 mode aperture defined by a single-ridged waveguide.
Abstract: Epitaxial layers of single crystals of gallium arsenide and similar compounds are formed by vapor deposition. A carrier gas flow is passed through a liquid halide of a group VB material to obtain a first vapor having a halogen, carrier gas and group VB material. The carrier gas flow is monitored and adjusted to obtain a predetermined mass of halogen and second material in this raw vapor. A final reactor input vapor is obtained with constant concentration and constant flow going into a reactor by monitoring the total volume of carrier gas in the raw vapor as added per unit of time and adjusting the raw vapor by adding a volume of additional carrier gas to a predetermined value to form a final reactor input vapor. The reaction and deposition of the epitaxial layer is then carried out in a reactor.