| Effect of Electrode Loss on the Dynamic Range of Linearized Directional Coupler Modulators |
01 FEB 2006 |
4 pages |
| Authors:
George A. Brost; Richard Michalak; Paul Payson; Kevin Magde; AIR FORCE RESEARCH LAB ROME NY
|
 | Numerical simulations were used to study the effect of electrode loss on the two-tone spur-free dynamic range (SFDR) of analog photonic links with linearized directional coupler modulators. Radio-frequency loss in the traveling wave electrode significantly limits the frequency bandwidth over which this class of electrooptic modulator can effectively enhance the SFDR. |
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| Lifetime and Longevity of an Intense, Photoconductivity - Switched Stacked Blumlein Modulator for Ultra - Wideband HPM Applications |
28 JUL 2003 |
58 pages |
| Authors:
Carl B. Collins; Farzin Davanloo; TEXAS UNIV AT DALLAS RICHARDSON CENTERFOR QUANTUM ELECTRONICS
|
| In this work, experiments with the stacked Blumlein prototype pulsers were conducted under different conditions of operation at power levels bypassing 100 MW. Special attention was placed on broadening of the current channels in the avalanche photoconductive switch in order to improve lifetime. The mechanical and semiconductor properties of amorphic diamond were employed to improve the lifetime by coating the switch cathode or anode areas or both. Issues concerning the ... |
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| Fiber Optic Digital Transmission System |
01 JUL 1997 |
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| Authors:
Willaim K. Burns; Ganesh K. Gopalakrishnan; DEPARTMENT OF THE NAVY WASHINGTON DC
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 | A transmission system responsive to an electrical input information signal includes means for modulating the input signal with a microwave subcarrier signal to produce a subcarrier modulated signal. A first interferometric modulator responsive to a source light and to the subcarrier modulated signal produces a first modulated optical signal. A second interferometric modulator cascade coupled to the first modulator and being responsive to the first modulated optical signal and to ... |
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| Credential Tracking System. |
20 SEP 1994 |
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| Authors:
Socrates A. Longas; Robert A. Leverance; DEPARTMENT OF THE NAVY WASHINGTON DC
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| A microwave carrier signal emitted from a tracker unit is amplitude modulated periodically at different preset modulation frequencies during spaced intervals between established time slots. The carrier signal is detected by differently coded credential units within a reception zone whereby such signal is demodulated at the different modulating frequencies to produce reply signals at one of several different code frequencies during one of the time slots dependent on the credential ... |
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| Use of Allpass Networks to tune the Center Frequency of Sigma Delta Modulators |
NOV 1993 |
6 pages |
| Authors:
Fred Harris; Bob Caulfield; Bill McKnight; NAVAL COMMAND CONTROL AND OCEAN SURVEILLANCE CENTER RDT AND E DIV SAN DIEGO CA
|
| Standard sigma-delta modulators use feedback around 1-bit quantizers to transform open loop integrator poles into closed loop transmission zeros of the noise transfer function. The DC transmission zeros permit high resolution quantization of data over a frequency band in their neighborhood. Closed loop zeros can be shifted to arbitrary spectral locations by doubling the number of integrators and then applying local feedback around integrator pairs thereby converting them to resonators. ... |
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| Magnetostatic Waves-Based Integrated Optic Bragg Cell Modules with Applications to RF Signal Processing |
93 |
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| Authors:
Chen S. Tsai; CALIFORNIA UNIV IRVINE
|
| Two major achievements were made during the third program year (July 1, 1992 to June 30, 1993): First, a complete analysis on ion-milled waveguide lenses in a YIG-GGG layer structure aimed at the key parameters and guidelines for design and fabrication of such waveguide lenses has been carried out. Second, a high-speed wideband integrated magnetooptic (MO) frequency shifter/ modulator has been realized, for the first time, using a YIG-GGG tapered ... |
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| Low-Frequency Noise Reduction in SQUID Measurements Using Laser Switching |
JUN 92 |
28 pages |
| Authors:
Blas Cabrera; STANFORD UNIV CA DEPT OF PHYSICS
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| Reduce SQUID noise in measurements which are intrinsically low frequency or dc. Such low frequency measurements fall below the 1/f knee of the noise energy spectrum and the SQUID performance is degraded substantially below the often quoted white noise levels. We intend to improve the low frequency noise using input circuit modulation at a frequency above the 1/f knee, up- converting the signal in frequency. In our scheme the noise ... |
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| Instantaneous Frequency Measurement Receiver with Digital Processing. |
30 DEC 1986 |
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| Authors:
James B. Tsui; DEPARTMENT OF THE AIR FORCE WASHINGTON DC
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| The receiver comprises a 90 deg hybrid and analog-to-digital converters between the RF section and digital processing; which makes it possible to eliminate a phase correlator, four diode detectors and two differential amplifiers used in previous IFM receivers to obtain the sine and cosine signal samples at an initial time and a delayed time. (Patents) |
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| What SAW Can Learn from BAW: Implications for Future Frequency Control, Selection, & Signal Processing, |
1980 |
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| Authors:
T. Lukaszek; A. Ballato; ARMY ELECTRONICS RESEARCH AND DEVELOPMENT COMMAND FORT MONMOUTH NJ ELECTRONIC S TECHNOLOGY/DEVICES LAB
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| Stimulated Brillouin Scattered (SBS) Tuned Laser. |
24 FEB 1976 |
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| Authors:
Richard Swart Hughes; DEPARTMENT OF THE NAVY WASHINGTON D C
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| The patent relates to a stimulated Brillouin scattered (SBS) tuned laser which uses stimulated Brillouin scattering. The output laser beam produces the acoustic wave that scatters the laser beam to thereby provide the scanning which impacts on a retroflective grating to provide a change in the frequency of the output laser beam. |
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| Miniature Molecular Frequency Source. |
FEB 1976 |
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| Authors:
J. J. Gallagher; GEORGIA INST OF TECH ATLANTA ENGINEERING EXPERIMENT STATION
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| An investigation has been performed to determine the characteristics of a miniature stabilized CO2 laser. The investigation included studies of miniature CO2 lasers, external frequency modulators, and room temperature 4.3 micrometers detectors. Lamb dip observations in the 4.3 micrometers fluorescence of CO2 have been detected with a 77 InSb detector employing both internal and external fluorescence cells. A small molecular frequency source has been assembled. The critical design parameters for ... |
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| Frequency Conversion with Double Modulation of Light in Light Rangefinders, |
16 OCT 1973 |
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| Authors:
I. I. Adrianova; L. N. Asnis; A. I. Vereshchaka; Z. V. Nesterova; yu. v. popov; ARMY FOREIGN SCIENCE AND TECHNOLOGY CENTER CHARLOTTESVILLE VA
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| Nonlinear distortions are studied with dual modulation by polarization resulting from the use of light modulation. Nonlinear distortions can be reduced by selecting operating modes of the light modulator and converter. Thus, an optical-radiation modulator and converter in a light range finder can be used with frequency conversion and dual light modulation, thereby reducing the frequency, and the problems connected with high frequency. |
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| Telemetry Standards |
MAY 73 |
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| Authors:
RANGE COMMANDERS COUNCIL WHITE SANDS MISSILE RANGE NM INTER- RANGE INSTRUMENT ATION GROUP
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Reports by Keyword(s)
*FREQUENCY MODULATORS
