22,891 research outputs found
Development of a color display capability
Color display capabilities for digital computer
Experimental L-band SST satellite communications/surveillance terminal study. Volume 5 - Aircraft terminal definition
Aircraft terminal designs for experimental and operational supersonic transport for L band satellite air traffic contro
Apollo experience report: Development flight instrumentation
Development flight instrumentation was delivered for 25 Apollo vehicles as Government-furnished equipment. The problems and philosophies of an activity that was concerned with supplying telemetry equipment to a space-flight test program are discussed. Equipment delivery dates, system-design details, and flight-performance information for each mission also are included
Development of a superconductor magnetic suspension and balance prototype facility for studying the feasibility of applying this technique to large scale aerodynamic testing
The basic research and development work towards proving the feasibility of operating an all-superconductor magnetic suspension and balance device for aerodynamic testing is presented. The feasibility of applying a quasi-six-degree-of freedom free support technique to dynamic stability research was studied along with the design concepts and parameters for applying magnetic suspension techniques to large-scale aerodynamic facilities. A prototype aerodynamic test facility was implemented. Relevant aspects of the development of the prototype facility are described in three sections: (1) design characteristics; (2) operational characteristics; and (3) scaling to larger facilities
125 - 211 GHz low noise MMIC amplifier design for radio astronomy
To achieve the low noise and wide bandwidth required for millimeter wavelength astronomy applications, superconductor-insulator-superconductor (SIS) mixer based receiver systems have typically been used. This paper investigates the performance of high electron mobility transistor (HEMT) based low noise amplifiers (LNAs) as an alternative approach for systems operating in the 125 — 211 GHz frequency range. A four-stage, common-source, unconditionally stable monolithic microwave integrated circuit (MMIC) design is presented using the state-of-the-art 35 nm indium phosphide HEMT process from Northrop Grumman Corporation. The simulated MMIC achieves noise temperature (T_e) lower than 58 K across the operational bandwidth, with average T_e of 38.8 K (corresponding to less than 5 times the quantum limit (hf/k) at 170 GHz) and forward transmission of 20.5 ± 0.85 dB. Input and output reflection coefficients are better than -6 and -12 dB, respectively, across the desired bandwidth. To the authors knowledge, no LNA currently operates across the entirety of this frequency range. Successful fabrication and implementation of this LNA would challenge the dominance SIS mixers have on sub-THz receivers
Use of analog computer for the equalization of electromagnetic shakers in transient testing
Analog computer to perform open-loop equalization for multishaker environmental vibration testin
Digital Offset Calibration of an OPAMP Towards Improving Static Parameters of 90 nm CMOS DAC
In this paper, an on-chip self-calibrated 8-bit R-2R digital-to-analog converter (DAC) based on digitally compensated input offset of the operational amplifier (OPAMP) is presented. To improve the overall DAC performance, a digital offset cancellation method was used to compensate deviations in the input offset voltage of the OPAMP caused by process variations. The whole DAC as well as offset compensation circuitry were designed in a standard 90 nm CMOS process. The achieved results show that after the self-calibration process, the improvement of 48% in the value of DAC offset error is achieved
Random Generation of Arbitrary Waveforms for Emulating Three-Phase Systems
This paper describes an apparatus for generating a
signal representative of steady-state and transient disturbances
in three-phase waveforms of an ac electrical system as described
in IEEE Std 1159-09. It can be configured as a synthesizer of
randomly distorted signals for different applications: for testing
the effects of disturbed grid on equipment and to generate patterns
of electrical disturbances for the training of artificial neural
networks, which are used for measuring power quality tasks. For
the first purpose, voltage and current amplifiers are added in the
output stage, which allows the generation of disturbed signals at
grid level.Comisión Interministerial de Ciencia y Tecnología DPI2006-15467-C02-01Comisión Interministerial de Ciencia y Tecnología DPI2006-15467-C02-0
Single parameter testing Quarterly report
Single parameter testing of ac and dc amplifier
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