WAVEFORM GENERATORS - Storming Media

Time-Reversal Based Range Extension Technique for Ultra-Wideband (UWB) Sensors and Applications in Tactical Communications and Networking

16-Jan-2009

49 pages

Authors: Peng Zhang; Nan Guo; Zhen Hu; Yu Song; Robert C Qui; TENNESSEE TECHNOLOGICAL UNIV COOKEVILLE

The full text of this report is available for sale.

This report summarizes our research and development work in the last quarter of year 2008. We have reached a practical limit in terms of sampling rate and bandwidth. Listed below are major achievements during the quarter: (1) improved waveform generator: FPGA coding with respect to readability, quantization at the transmitter has been increased from ternary to 8-bit, and sampling rate has been increased from 500 Ms/s to 1 Gs/s; (2) ...

Time-Reversal Based Range Extension Technique for Ultra-Wideband (UWB) Sensors and Applications in Tactical Communications and Networking

16 JAN 2008

46 pages

Authors: Robert C. Qiu; Nan Guo; Qiang Zhang; Chenming Zhou; Zhen Hu; Peng Zhang; Dalwinder Singh; Corey Cooke; TENNESSEE TECHNOLOGICAL UNIV COOKEVILLE DEPT OF ELECTRICAL ENGINEERING

This technical report (quarterly) details the work for Office of Naval Research (ONR) by Tennessee Tech. The goal of this project-jointly funded by ONR, NSF, and ARO-is to build a general purpose testbed with time reversal capability at the transmitter side. The envisioned application is for UWB sensors and tactical communications in RF harsh environments where multipath is rich and can be exploited through the use of time reversal. The ...

Applications of Optical Coherent Transient Technology to Pulse Shaping, Spectral Filtering, Arbitrary Waveform Generation and RF Beamforming

15 APR 2006

72 pages

Authors: W. R. Babbitt; Mingzhen Tian; Kelvin Wagner; MONTANA STATE UNIV BOZEMAN DEPT OF PHYSICS

Under research conducted by Montana State University and the University of Colorado, several optical coherent transient (OCT) devices was developed and demonstrated, including pulse shaping, arbitrary waveform generation, optical spectral filtering, time integrating correlator, Doppler shifted arrays, and optical beam scanning. OCT's are particularly well suited for RF photonic processing because of their large bandwidths (tens to hundreds of 6Hz), spectral resolution well below a MHz, and time-bandwidth products (TBP) ...

Applications of Optical Coherent Transient Technology to Pulse Shaping, Spectral Filtering Arbitrary Waveform Generation and RF Beamforming

14 APR 2006

72 pages

Authors: William R. Babbitt; Mingzhen Tian; Kelvin Wagner; MONTANA STATE UNIV BOZEMAN DEPT OF PHYSICS

Under research conducted by Montana State University and the University of Colorado, several optical coherent transient (OCT) devices were developed and demonstrated, including pulse shaping, arbitrary waveform generation, optical spectral filtering, time integrating correlator, Doppler shifted arrays, and optical beam scanning. OCTs are particularly well suited for RF photonic processing because of their large bandwidths (tens to hundreds of GHz), spectral resolution well below a MHz, and time bandwidth products ...

Results of July 2003 Space-Time Delta-Sigma Hardware Experiments at China Lake

26 SEP 2005

14 pages

Authors: Dan P. Scholnik; Jeffrey O. Coleman; Josef Brandriss; Donald Bowling; Michael Neel; Scot Rogala; Frank Schiavone; NAVAL RESEARCH LAB WASHINGTON DC RADARDIV

This report presents an overview of the test setup, procedures, and important results from the July 2003 experiments. It does not document an operational or prototype system, provide any mathematical background (references are provided), or contain sufficient detail to recreate the experiment. Spatio-temporal delta-sigma modulation, a concept developed at NRL, is an extension of conventional delta-sigma modulation to signals that are functions of space as well as time. At the ...

Current Efforts on Developing a HWIL Synthetic Environment for LADAR Sensor Testing at AMRDEC

2005

10 pages

Authors: Hajin J. Kim; Michael C. Cornell; Charles B. Naumann; ARMY AVIATION AND MISSILE COMMAND REDSTONE ARSENAL AL MISSILE RESEARCH DEVELOPMENT AND ENGINEERING CENTER

Efforts in developing a synthetic environment for testing LADAR sensors in a hardware-in-the-loop simulation are continuing at the Aviation and Missile Research, Engineering, and Development Center (AMRDEC) of the U.S. Army Research, Engineering and Development Command (RDECOM). Current activities have concentrated on developing the optical projection hardware portion of the synthetic environment. These activities range from system level design down to component level testing. Of particular interest have been schemes ...

Optical Processing of Microwave Signals - Part B

20 AUG 2003

Authors: Jean Chazelas; THALES RESEARCH AND TECHNOLOGY ORSAY (FRANCE)

The full text of this report is not available and therefore is not for sale. This information is provided for reference purposes only.

The availability of optoelectronic components operating up to 20 GHz brings attractive perspectives for optical processing of microwave signals. Furtherinore optically carried microwave signals can experience large time delays, especially in fiber based systems, providing time-frequency products in the range between 100 and 1000. Owing to their inherent parallel processing capabilities, optoelectronic architectures are well suited for the implementation in radar and electronic warfare systems of basic functions such as ...

Spectral Analysis and Sonification of Simulation Data Generated in a Frequency Domain Experiment

SEP 2002

112 pages

Authors: Hsin-Fu Wu; NAVAL POSTGRADUATE SCHOOL MONTEREY CA

In this thesis, we evaluate the frequency domain approach for data farming and assess the possibility of analyzing complex data sets using data sonification. Data farming applies agent-based models and simulation, computing power, and data analysis and visualization technologies to help answer complex questions in military operations. Sonification is the use of data to generate sound for analysis. We apply a frequency domain experiment (FDE) to a combat simulation and ...

Status of the Eltrap Project

24 JUN 2002

6 pages

Authors: M. Amoretti; G. Bettega; F. Cavaliere; M. Cavenago; F. De Luca; MILAN UNIV (ITALY)

The Malmberg-Penning trap Eltrap recently installed at the University of Milano, features a magnetic field with a high degree of uniformity in a relatively large plasma volume, and an enhanced light collection by the CCD camera. A modular electrode design allows several variations of the experimental configuration, suitable both for electron confinement and beam studies. The major electronic components of the apparatus are a waveform generator, which controls the inject-hold-dump ...

An Assessment of the Effects of Four Acoustic Energy Devices on Animal Behavior

OCT 2000

80 pages

Authors: Clifford F. Sherry; Michael C. Cook; G. C. Brown; James R. Jauchem; James H. Merritt; VERIDIAN CORP SAN ANTONIO TX

To determine if narrow-band, high-intensity acoustic energy in the audible frequency range could be used as a non-lethal weapon, four acoustic devices were tested: (a) a compressed-air-driven siren (CADS); (b) a combustion- driven siren (the Dismounted Battlefield Battle Laboratory, or DBBL); (c) an impulsive acoustic device, the Sequential Arc Discharge Acoustic Generator (SADAG); and (d) a complex waveform generator, the Gayl Blaster. The Primate Equilibrium Platform (PEP) is a continuous, ...

Submerged Object Detection and Classification System.

23 MAR 1999

Authors: Richard W. Harrison; John F. Scarzello; OFFICE OF THE SECRETARY OF THE NAVY WASHINGTON DC

A detection and classification system for underwater objects uses a transmitting unit and a receiving unit. The transmitting unit comprises a waveform generator, a power amplifier, and a transmitting antenna. The receiving unit comprises a receiving antenna a pre-amplifer a first harmonic suppressor a digitizer, and a computer. The transmitting unit radiates an analog electromagnetic wave signal into a conductive medium such as seawater which the receiving unit detects and ...

An Ultra-Low Phase Noise Multi-Frequency Source

13 NOV 1998

16 pages

Authors: Jean De Graaf; Brian Connolly; NAVAL RESEARCH LAB WASHINGTON DC SEARCH RADAR BRANCH

Design and construction of a prototype X-band pulse-Doppler radar having 90 dB of dynamic range (after pulse integration and into a 1 MHz band) calls for a ultra-low phase noise multi-frequency source. The generated frequencies for local oscillators (LOs), waveform generation, and data acquisition typically cover the spectrum from HF to X-band and must be coherent. However, using a separate synthesizer for each required frequency would be both costly and ...

Digital Beam Synthesis (DBS) for a High Capability Opto-Electronic Radar (HICAPOR)

25 SEP 97

88 pages

Authors: Alvin M. Despain; John F. Vesecky; MITRE CORP MCLEAN VA JASON PROGRAM OFFICE

Digital beam synthesis using a high capability opto-electronic radar (HICAPOR) by Alvin M. Despain and John F. Vesecky. This JASON study investigates the capabilities of HICAPOR by calculating the antenna beam patterns formed by typical implementations of this concept. A wide variety of parameter choices are investigated and antenna patterns for HICAPOR are compared with conventional phased array and true time delay techniques of beam formation. The presentation begins with ...

Acoustic Element Tester for an Array of Hydrophones

05 AUG 1997

Authors: Foster L. Striffler; DEPARTMENT OF THE NAVY WASHINGTON DC

An apparatus for testing an individual hydrophone element in an axially extending hydrophone array includes a pressure wave generator, an insonifier for directing the generated pressure waves toward a selected one of the elements of the array and a monitor for measuring the output of the array responsive to the generated arrays. The pressure wave generator is isolated so it does not produce pressure waves externally thereto. The insonifier includes ...

Mine Sweeping System for Magnetic and Non-Magnetic Mines.

28 JAN 1997

Authors: John F. Scarzello; Peter B. Keller; Richard W. Harrison; DEPARTMENT OF THE NAVY WASHINGTON DC

A mine sweeping system including deployable horizontal antennas to establish a detection and navigation grid extending underwater from a beach to a distance offshore. A computer-controlled transmitter unit having a waveform generator and amplifier, transmits signals to each antenna, at unique frequencies and phases for different spatial locations within the grid. An autonomous underwater vehicle having multi-integrated sensors detects anomalies in the electromagnetic field caused by both magnetic and non-magnetic ...

(DURIP-95) Instrumentation for the Development of Time-Domain Optical Storage Processing and Routing Technologies

DEC 96

6 pages

Authors: Thomas W. Mossberg; OREGON UNIV EUGENE DEPT OF PHYSICS

The present grant was an instrumentation grant. Its purpose to provide funds to acquire instrumentation supportive of research work in the areas of time-domain optical storage, processing, and routing technologies. The complete catalog of instrumentation items requested or currently available equivalents have been ordered, received, and incorporated into ongoing research supported under AFOSR grants F49620-95-1-O465 and F49620-96-1-0259

Acoustic Element Tester for an Array of Hydrophones.

22 MAR 1996

18 pages

Authors: Foster L. Striffler; DEPARTMENT OF THE NAVY WASHINGTON DC

Ultra Wide Band (UWB) Radar Detection Analysis and Demonstration Program, Phases 1 and 2. Volume 1

APR 95

259 pages

Authors: Donald D. Weiner; Tapan K. Sarkar; Hong Wang; SYRACUSE UNIV NY DEPT OF ELECTRICAL AND COMPUTER ENGINEERING

This report presents the T-pulse concept. The first part presents the T-pulse as a flexible tool for the analysis of waveforms exhibiting time- frequency localization. This is useful when T-pulse processing is performed on receive. It is shown how the T-pulse generalizes the Fourier, Gabor and Wavelet transforms. The analysis includes both the continuous and the discrete cases. The second part of this report presents the T-pulse as a waveshaping ...

Development of a Bulk Current Injection Direct-Drive System to Test System Level Components with Stress Waveforms that are Encountered During Full Threat Indirect Effects Lightning

7 pages

Authors: Sam Frazier; Kurt Sebacher; NAVAL AIR WARFARE CENTER AIRCRAFT DIV PATUXENT RIVER MD

The NAWCAD has developed an effective lightning BCI direct drive system that can be used to inject indirect effects waveforms onto test point cables. The amplitude and shapes of these waveforms correspond to what would be seen caused by indirect effect lightning with a 6 odB margin. The waveform normalization and the load impedance normalization processes mentioned in the text have allowed near exact replication of waveforms. This BCI direct ...

Submerged Object Detection and Classification System

16 APR 1993

19 pages

Authors: Richard Harrison; John Scarzello; DEPARTMENT OF THE NAVY WASHINGTON DC

A detection and classification system for underwater objects uses a transmitting unit and a receiving unit. The transmitting unit comprises a waveform generator, a power amplifier, and a transmitting antenna. The receiving unit comprises a receiving antenna, a pre-amplifier, a first harmonic suppressor, a digitizer, and a computer. The transmitting unit radiates an analog electromagnetic wave signal into a conductive medium such as seawater which the receiving unit detects and ...

Multiple Convergence Zone Acoustic Telemetry Feasibility Test Report

NOV 91

Authors: Josko A. Catipovic; Keith Von Der Heydt; John S. Merriam; Geir H. Sandsmark; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA

This report describes a multiple CZ acoustic telemetry experiment conducted off the coast of California 1/28/90 - 2/2/90. The goal was to design a maximally robust high speed underwater modem suitable for data telemetry for submerged platforms and moorings. Six modulation methods were used to transmit data at rates from 1 to 1000 baud, corresponding to bit rates up to 3kbit/sec. The modulation formates were: (1) Multiple Frequency Shift Keying ...

Radioactive Particle Densitometer Apparatus Employing Modulation Circuitry.

17 SEP 1991

Authors: Herbert A. Johnson; DEPARTMENT OF THE NAVY WASHINGTON DC

An apparatus and method for measuring the density of a low density medium such as air by measuring the absorption of radioactivity decay particles such as alpha particles in the air. The apparatus includes a source of alpha particles from which alpha particles are directed to the air sample to be measured. An alpha particle detector spaces from the source by a path distance which traverses the air sample. The ...

Introduction of a Current Waveform, Waveshaping Technique to Limit Conduction Loss in High-Frequency DC-DC Converters Suitable for Space Power

JUN 90

Authors: Douglas P. Miller; NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Space power supply manufacturers have tried to increase power density and construct smaller, highly efficient power supplies by increasing switching frequency. Incorporation of a power MOSFET as a switching element alleviates switching loss. However, values of R sub DS(on) (drain-to-source resistance in the on-state) for mOSFET's are of such magnitude to produce greater on-state losses than an equivalent BJT operated in saturation. This research serves to introduce a design concept, ...

Redondo Beach King Harbor, California, Design for Wave Protection. Coastal Model Investigation

APR 90

Authors: Robert R. Bottin Jr.; Marvin G. Mize; COASTAL ENGINEERING RESEARCH CENTER VICKSBURG MS

A 1:75-scale, three dimensional hydraulic model was used to investigate the design of proposed breakwater modifications at Redondo Beach King Harbor, with respect to wave conditions in the harbor. The model reproduced approx. 8,800 ft of the shoreline and included the existing harbor and offshore bathymetry in the Pacific Ocean to a depth of -60 ft. Improvement plans consisted of raising the crest elevation of portions on the north breakwater ...

Implications of Cloud Obscuration on Ground-Based Laser Systems for Strategic Defense

12 MAR 90

Authors: Michael T. Tavis; Scott W. Levinson; Kathryn M. Parker; AEROSPACE CORP EL SEGUNDO CA

The evolution and the current status of the Strategic Defense System Phase II Ground-Based Laser (GBL) System Concept is reviewed in this report. In particular, the impact of clouds on system configuration and site selection is discussed. By using current models of correlated probabilities of cloud-free line of sight and cloud-free arc (CFLOS4D and CFARC) for several ground stations with cloud realizations provided by the Boehm Saw Tooth generator, we ...

Current and Temperature Effects at Eighteenmile Creek as a result of Harbor Improvements at Olcott Harbor, New York. Hydraulic Model Investigation

MAR 90

Authors: Robert R. Bottin Jr; COASTAL ENGINEERING RESEARCH CENTER VICKSBURG MS

A 1:60-scale (undistorted) hydraulic model of Olcott Harbor was used to determine the effects of proposed improvements on creek temperatures and currents at Eighteenmile Creek as they entered Lake Ontario. The model reproduced approx. 3,300 and 3,600 ft of the NY shoreline on the east and west sides of the harbor, respectively, about 3,000 ft of the lower reaches of Eighteenmile Creek, and sufficient offshore bathymetry in Lake Ontario to ...

Waves in Ship Tanks. Part 1. Generating a Random Sea

JUL 89

Authors: D. K. Fryer; ADMIRALTY RESEARCH ESTABLISHMENT GOSPORT (UNITED KINGDOM)

The working fluid in a ship tank in which model ships are tested is the same as the working fluid in the prototype system (the sea) although probably not saline. This implies that equivalence of the Reynolds, Froude, Weber and Mach numbers between model and prototype will not be possible. Gravity waves on water are principally characterised by the Froude number, so the models which are discussed in this paper ...

Cryocooler Systems Demonstration

31 AUG 87

Authors: R. D. Sandell; A. H. Silver; TRW SPACE AND TECHNOLOGY GROUP REDONDO BEACH CA

TRW successfully transferred Stirling-cycle cryocooler technology from its development at NBS to industry. We installed, modified, and operated a small, plastic, five-stage Stirling cycle refrigerator which was developed at the National Bureau of Standards and furnished to TRW for this project. We also designed and fabricated a new gas handling system, pressure wave generator and displacer drive, and fiber-designed, fabricated, and operated a monolithic thin film SQUID gradiometer on a ...

Pulse Width Modulator Controller Design for a Brushless DC Motor Position Servo

JUN 87

Authors: Vincent S. Rossitto; NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Recent interest in positioning cruise missile flight control surfaces using electromechanical actuation has prompted a detailed study of brushless dc motor performance in such an application. While the superior response characteristics of these electronically commutated motors are particularly well suited to unidirectional velocity drives, destructive electrical transients associated with rotational reversals of the motor limit its positioning performance. This thesis involves computer aided design of a functionally robust brushless dc ...

Flexible (Multi-Mode) Waveform Generator.

30 DEC 1986

Authors: Paul W. Goetz; Kim R. Merley; DEPARTMENT OF THE AIR FORCE WASHINGTON DC

The generation waveforms is accomplished using: two random access memories (RAM), a digital-to-analog converter (DAC), two modulators, two oscillators, and multiplier. The computer inputs a set of digital waveforms and a first control signal into the first RAM which, when directed, conducts them to the DAC. The DAC converts the digital waveform and first control signal to the first modulator. The first modulator produces an output signal by single sideband ...

KELSEA: An Interactive Computer Code for Kelvin and Random Ambient Sea Waves

30 SEP 86

Authors: G. A. Keramidas; H. T. Wang; J. A. Burke; W. Bauman; NAVAL RESEARCH LAB WASHINGTON DC

This report covers the theoretical and numerical aspects of random ambient sea wave realizations, and the computer code for generating such waves. The mathematical model for random ambient sea waves is discussed in the first part of this report together with the superposition of these waves with Kelvin waves. The second part of the report covers the development and structure of the computer program. A detailed explanation is given for ...

The Emergence of Raster Based CAD (Computer Aided Design) Technology.

JUN 1986

Authors: C. Schroeder

In recent years, a new raster based CAD technology has emerged to meet the challenge of extending the many benefits of CAD into the vast arena of existing paper based drawings and documents. The emerging raster CAD technology traces its origins to early applications in cartography and electronic publishing. Recent advances in laser imaging and CCD (charge coupled device) scanning technology along with the advent of low cost PC based ...

1985 Source Measurements. Volume 1. The August 1985 HLF-5 Measurement

FEB 86

Authors: K. Metzger; L. C. Russell; T. Birdsall; G. Bold; MICHIGAN UNIV ANN ARBOR COMMUNICATIONS AND SIGNAL PROCESSING LAB

In 1985, Cooley Electronic Laboratory (CEL) in conjunction with the Scripps Institution of Oceanography (SIO) and Woods Hole Oceanographic Institution (WHOI) measured the pulse responses of three acoustic sources used, or to be used, in making ocean acoustic propagation measurements. The three sources were the Hydroacoustics HLF-5 250 Hz (DW-224) source. THe basic goal of these measurements was to observe the source outputs at close range in a relatively controlled ...

The Development of a High Speed Exponential Function Generator for Linearization of Microwave Voltage Controlled Oscillators

OCT 85

Authors: J. F. Mickeal; J. J. Renaud; M. R. McMillan; DEFENCE RESEARCH ESTABLISHMENT OTTAWA (ONTARIO)

Voltage Controlled Oscillators used in radar signal simulators usually employ piecewise approximation linearizers to compensate for nonlinear frequency versus voltage tuning characteristics. A linearizer was developed which closely approximates an exponential (frequency/voltage) relationship found in many VCO's. This linearizer uses the forward biased (voltage/current) characteristic of a p-n junction to provide exponential linearization in a simple, thermally-stable, wide band circuit.

A Statistical Channel Model for Adaptive HF Communications via a Severely Disturbed Ionosphere

DEC 1983

Authors: D. M. Haines; ROME AIR DEVELOPMENT CENTER GRIFFISS AFB NY

Motivation for the resurgence of interest in improving HF communication is presented. This includes the continued widespread use of the HF band, and the new technology that now makes it feasible to vastly improve the historically poor quality of communications in this band. Non-conventional HF techniques or systems are classified into four general categories according to the technical specialties that spawned them. These categories are Adaptive Frequency Management. Digital Waveform ...

Multi-Tone Jammer.

27 JUL 1982

Authors: Loren R. Seidl; DEPARTMENT OF THE AIR FORCE WASHINGTON DC

A waveform capable of jamming some or all of the channels of a multiple channel receiver is developed by a multi-tone jammer that uses a digital counter and a digital/analog converter to generate a ramp voltage for a voltage controlled oscillator (VCO). The output of the VCO is modulated by a pin diode attenuator. The attenuator is controlled by a pattern generator synchronized with the digital counter to blank the ...

Programmable Pulse Generator. Operating Instructions

14 JAN 1982

Authors: J. W. Paradise; W. B. Allen; NAVAL OCEAN SYSTEMS CENTER SAN DIEGO CA

The generator is a versatile source of short bursts of 0.8-micron trigger pulses and variable-width pulses whose spacings and widths can be programmed over a wide range. It can be used as a source of precision complex logic signals with or rectangular waveforms and as a source of control signals for sequential operations. (Author)

Radar Waveform Synthesis for Target Identification

03 JUN 1981

Authors: Kun-Mu Chen; MICHIGAN STATE UNIV EAST LANSING DIV OF ENGINEERING RESEARCH

A new scheme for radar detection and discrimination, the radar waveform synthesis method, is investigated. This scheme consists of synthesizing an aspect-independent waveform for the incident radar signal which excites an arbitrarily oriented target in such a way that the return radar signal from the target contains only a single natural resonance mode of the target in the late- time period. When the synthesized incident radar signal for exciting a ...

Radar Waveform Synthesis for Target Identification.

15 MAY 1980

Authors: Kun-Mu Chen; MICHIGAN STATE UNIV EAST LANSING DIV OF ENGINEERING RESEARCH

A new scheme for radar detection and discrimination, the radar waveform synthesis method, is investigated. This scheme consists of synthesizing the waveform of an incident radar signal which excites the target in such a way that the return radar signal from the target contains only a single natural resonance mode of the target. When the synthesized incident radar signal for a known, preselected target is applied to a wrong target, ...

Doppler Compensated Digital Non-Linear Waveform Generator Apparatus.

29 APR 1980

Authors: Thomas P. Sifferlen; Fritz Steudel; DEPARTMENT OF THE AIR FORCE WASHINGTON DC

/THE PRESENT INVENTION UTILIZES A DIGITAL WAVEFORM GENERATOR FOR Doppler compensation of waveforms to correct for dispersion due to target velocity. The apparatus utilizes a modified binary rate multiplier to produce an accurate clock signal that is related to target velocity. This variable or Doppler clock is used to drive a digital waveform generator to produce a signal for transmission that is predistorted in an opposite sense from the distortion ...

Direct Reading Capacitance Meter.

06 MAR 1980

Authors: Clifford O. Shaw; DEPARTMENT OF THE NAVY WASHINGTON DC

This invention relates to an apparatus for measuring capacitance, especially large capacitance. The resulting measurement is displayed on a meter calibrated in capacitance. One method of determining the capacitance of a large, unknown capacitor is to charge it to a predetermined DC voltage, then discharge it through a known resistor and an SCR while observing the discharge wave form on an oscilloscope. Another method is to insert the unknown capacitor ...

A Constant Amplitude Variable Frequency Synchronized Linear Ramp Generator.

03 OCT 1979

Authors: Urbono Manifredi; DEPARTMENT OF THE NAVY WASHINGTON DC

A constant amplitude, variable frequency, synchronizied, linear ramp generator is disclosed for generating a sawtooth waveform signal, whose amplitude is independent of frequency. A capacitor is charged by a voltage controlled current source, which is responsive to a feedback control signal provided by an integrator; and subsequently discharged by a clamp, which is responsive to a trigger pulse signal, so as to establish a ramp voltage across the capacitor. The ...

Design of a Prototype Microcomputer Driven Training Device for an Air Force Maintenance School.

AUG 1979

189 pages

Authors: Michael F. Winthrop; ELECTRONIC SYSTEMS DIV HANSCOM AFB MA

Microcomputers are no longer toys, they are cheap computers. This project proved that a commercial, 'off the shelf' microcomputer could run a simulator used in an Air Force Technical Training school. Research through the Defense Documentation Center (now the Defense Technical Information Center) showed nothing comparable in DoD. Commercial producers of trainers were also unable to show equivalent capability. A reproducible method to evaluate microcomputers is shown and used. Circuits ...

Analog and Digital Circuit Tester.

17 FEB 1978

Authors: Dean A. Winkler; DEPARTMENT OF THE NAVY WASHINGTON D C

This is a report on an automatic tester for signularly testing a plurality of different types of standard electronic modules. A test program is written for each type of standard electronic module and this test data is stored on cassette tape. As the tester is adaptable for testing different types of modules, interface and switching matrix between the tester and the module under test is accomplished by an interface card ...

Frequency and Amplitude Characteristics of a High-Repetition-Rate Hybrid TEA-CO2 Laser,

FEB 1978

Authors: J. -L. Lachambre; P. Lavigne; M. Verreault; G. Otis; DEFENCE RESEARCH ESTABLISHMENT VALCARTIER (QUEBEC)

The envelope and frequency characteristics of the output pulse of a high-repetition-rate hybrid TEA-CO2 laser are presented. Both the intrapulse and interpulse laser frequency stability are experimentally determined at repetition rates up to 300 Hz. The recovery of the CW laser signal following the generation of the TEA laser pulse is analyzed theoretically and experimentally. Short term reproducibilities of + or - 2 MHz are observed at a pulse repetition ...

High Power Spark Gap Optimization.

16 JUN 1977

Authors: MAXWELL LABS INC SAN DIEGO CALIF

This report completes the High Power Spark Gap Optimization program, which was begun under a previous contract with Wright-Patterson AFB. In that program, data was obtained in the power range of 1-5 MW to investigate switch performance at rep-rates up to 500 pps, and at voltages up to 60 kV. In the current program, the main experimental objectives were to demonstrate spark gap power above 5 MW per switch, and ...

BCSG-76 Signal Source Documentation.

MAR 1977

Authors: Kurt Metzger; L. Wayne Von Wald; MICHIGAN UNIV ANN ARBOR COOLEY ELECTRONICS LAB

This memo serves to document the design and operation of the BCSG-76 signal source. This unit is the latest in a series of signal sources designed and constructed at Cooley Electronics Laboratory for use in performing acoustic propagation studies. (Author)

An Improved Waveform Generator.

09 FEB 1977

Authors: Wise; DEPARTMENT OF THE AIR FORCE WASHINGTON D C

A waveform generator apparatus utilizing digital techniques to synthesize waveforms in conjunction with repetitive calculations and storage of constant factors in a computer during waveform generation. (Author)

Simulator for Doppler Radar Returns from Precipitation.

25 JAN 1977

Authors: Richard W. Fetter; DEPARTMENT OF THE NAVY WASHINGTON D C

A waveform generator particularly suited for the simulation of Doppler radar returns from precipitation is provided. Also, waveform pattern selected capability is provided and spectral shapes such as Gaussian distributions, symmetrical and asymmetrical bimodal spectral shapes or flat spectra can be chosen and generated. The device is portable and capable of being used in the field. The purpose of simulating such returns is so that a weather radar receiver and ...

A Blumlein Modulator for a Time-Varying Load.

OCT 1976

Authors: Sol Schneider; William H. Wright Jr.; Anthony J. Buffa; ARMY ELECTRONICS COMMAND FORT MONMOUTH N J

A modulator has been built to drive a time-varying-impedance load. A Blumlein circuit, with two identical pulse forming networks, was used to produce an effective voltage of twice the charging voltage. A dissipative clamper circuit was included to simulate a well-behaved load. The switch is a 10 section iterative cavity-grid thyratron designed for 250 kilovolts (kV) and 20 kiloamperes (kA) peak current. The modulator has been operated at 210 kV ...