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Search Publications by: Craig Nelson (Fed)

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Displaying 26 - 50 of 105

Reducing oscillator PM noise from AM-PM noise correlaiton

August 14, 2014
Author(s)
Archita Hati, Craig W. Nelson, David A. Howe
We present a new scheme for improving the phase modulated (PM) noise of an oscillator from correlation between amplitude modulated (AM) and PM noise. Experimental results of this correlation effect are presented. An improvement of almost 10 dB in the PM

Collapse of the Cross-spectral Function

May 22, 2014
Author(s)
Craig W. Nelson, Archita Hati, David A. Howe
Cross-spectral analysis is a mathematical tool for extracting the power spectral density of a correlated signal from two time series in the presence of uncorrelated interfering signals. We demonstrate and explain a set of amplitude and phase conditions

Correlation Measurements between PM and AM Noise in Oscillators

May 22, 2014
Author(s)
Archita Hati, Craig W. Nelson, David A. Howe
We discuss techniques for measuring the correlation between phase modulated (PM) and amplitude modulated (AM) noise in an oscillator and report results of such correlation in a few selected oscillators of similar size, weight, power consumption and

A collapse of the cross-spectral function in phase noise metrology

February 25, 2014
Author(s)
Craig W. Nelson, Archita Hati, David A. Howe
Cross-spectral analysis is a mathematical tool for extracting the power spectral density of a correlated signal from two time series in the presence of uncorrelated interfering signals. We demonstrate and explain a set of conditions where the detection of

Phase inversion and collapse of the cross-spectral function

December 5, 2013
Author(s)
Craig W. Nelson, Archita Hati, David A. Howe
Cross-spectral analysis is a mathematical tool for extracting the power spectral density of a correlated signal from two time series in the presence of uncorrelated interfering signals. We demonstrate and explain a set of conditions where the detection of

State-of-the-Art RF Signal Generation From Optical Frequency Division

September 2, 2013
Author(s)
Archita Hati, Craig W. Nelson, Corey A. Barnes, Danielle G. Lirette, Tara M. Fortier, Franklyn J. Quinlan, Jason A. DeSalvo, Andrew D. Ludlow, Till P. Rosenband, Scott A. Diddams, David A. Howe
We present the design of a novel, ultra-low phase-noise frequency synthesizer implemented with extremely low noise regenerative frequency dividers. This synthesizer generates eight outputs viz. 1.6 GHz, 320 MHz, 160 MHz, 80 MHz, 40 MHz, 20 MHz, 10 MHz and

Photonic microwave generation with high-power photodiodes

May 14, 2013
Author(s)
Tara M. Fortier, Franklyn J. Quinlan, Archita Hati, Craig W. Nelson, Jennifer A. Taylor, Yang Fu, Joe Campbell, Scott A. Diddams
We utilize and characterize high-power, high-linearity modified uni-traveling carrier (MUTC) photodiodes for low-phase-noise photonic microwave generation based on optical frequency division. When illuminated with 980 nm picosecond pulses from a repetition

Exploiting shot noise correlations in the photodetection of ultrashort optical pulse trains

March 10, 2013
Author(s)
Franklyn J. Quinlan, Tara M. Fortier, Haifeng (. Jiang, Archita Hati, Craig W. Nelson, Yang Fu, J. C. Campbell, Scott A. Diddams
Photocurrent shot noise represents the fundamental quantum limit of amplitude, phase and timing measurements of optical signals. It is generally assumed that non-classical states of light must be employed to alter the standard, time-invariant shot noise

Phase-Noise Measurement System for the Terahertz-Band

November 30, 2012
Author(s)
Jason A. DeSalvo, Archita Hati, Craig W. Nelson, David A. Howe
We present initial phase noise measurements in support of terahertz electronics, in the frequency range generally regarded as 0.1 to 10 THz. Using digital phase noise measurement techniques and an even-harmonic mixer, we achieve a phase noise measurement

Ultra-low noise regenerative frequency divider

November 11, 2012
Author(s)
Archita Hati, Craig W. Nelson, Corey A. Barnes, Danielle G. Lirette, Jason A. DeSalvo, David A. Howe
We designed ultra-low noise regenerative divider-by-2 circuits that operate at input frequencies of 20 MHz and 10 MHz. We achieved residual output-referred single-sideband phase noise below -162 dBc/Hz at 10 Hz offset for a single divider at these

A Sub-Sampling Digital PM/AM Noise Measurement System

September 1, 2012
Author(s)
Craig W. Nelson, David A. Howe
A digital phase/amplitude modulation (PM/AM) noise measurement systems (DNMS) implementing field progammable gate array (FPGA) based digital down converters (DDCs), and 250 MHz analog to digital converters (ADCs) is reported. Measurements in the first

Calibration uncertainty for the NIST PM/AM noise standards

July 31, 2012
Author(s)
Archita Hati, Craig W. Nelson, Neil Ashby, David A. Howe
NIST provides an on-site calibration service of the accuracy of phase modulation (PM) noise, amplitude modulation (AM) noise and noise floor of the measurement systems at a customer's site using one or more portable PM/AM secondary noise standards. In this

Sub-femtosecond absolute timing jitter with a 10 GHz hybrid photonic-microwave oscillator

June 7, 2012
Author(s)
Tara M. Fortier, Craig W. Nelson, Archita Hati, Franklyn J. Quinlan, Jennifer A. Taylor, Haifeng (. Jiang, Chin-Wen Chou, Till P. Rosenband, Nathan D. Lemke, Andrew D. Ludlow, David A. Howe, Christopher W. Oates, Scott A. Diddams
We present an optical-electronic approach to generating microwave signals with high spectral purity. By overcoming shot noise and operating near fundamental thermal limits, we demonstrate 10 GHz signals that have timing deviation from an ideal periodic

A hybrid 10 GHz photonic-microwave oscillator with sub-femtosecond absolute timing jitter

May 24, 2012
Author(s)
Tara M. Fortier, Craig W. Nelson, Archita Hati, Franklyn J. Quinlan, Jennifer A. Taylor, Haifeng (. Jiang, Chin-Wen Chou, Nathan D. Lemke, Andrew D. Ludlow, David A. Howe, Christopher W. Oates, Scott A. Diddams
We demonstrate a 10 GHz hybrid oscillator comprised of a phase stabilized optical frequency comb divider and a room temperature dielectric sapphire oscillator. Characterization of the 10 GHz microwave signal via comparison of two independent hybrid

A Sub-Sampling Digital PM/AM Noise Measurement System

May 24, 2012
Author(s)
Craig W. Nelson, David A. Howe
A digital phase/amplitude modulation (PM/AM) noise measurement system (DNMS) implementing field programmable gate array (FPGA) based digital down converters (DDCs), and 250 MHz analog to digital converters (ADCs) is reported. Performance in the first

Common-Arm Counter Propagating Phase Bridge for Vibration Sensitivity Measurement

May 24, 2012
Author(s)
Danielle G. Lirette, Corey A. Barnes, Archita Hati, Jason A. DeSalvo, Craig W. Nelson, David A. Howe
Current methods for measuring the vibration sensitivity of microwave devices are primarily limited by choice of cables connecting a stationary platform to a vibrating actuator. We experimentally compare the current ("conventional") method with a new (

Phase-Noise Measurement of a 670 GHz Source

May 24, 2012
Author(s)
Jason A. DeSalvo, Archita Hati, Craig W. Nelson, David A. Howe
We present phase-noise measurements in support of terahertz electronics. Using digital phase-noise measurement techniques and an even-harmonic mixer, we achieve a phase-noise measurement system in waveguide (WR1.5). At 670 GHz an upper bound of this system

PM-AM Correlation Measurements and Analysis

May 24, 2012
Author(s)
David A. Howe, Archita Hati, Craig W. Nelson, Danielle G. Lirette
We measure and analyze effects of nonlinear mixing of phase-noise modulation (PM) and amplitude-noise modulation (AM) in an oscillating signal by real-time correlations measured in the cross power spectral density (CPSD). We outline sensitive measurements

Ultra-low-noise Regenerative Frequency Divider for High Spectral Purity RF Signal Generation

May 24, 2012
Author(s)
Archita Hati, Craig W. Nelson, Corey A. Barnes, Danielle G. Lirette, Jason A. DeSalvo, Tara M. Fortier, Franklyn J. Quinlan, Andrew D. Ludlow, Till P. Rosenband, Scott A. Diddams, David A. Howe
We implement an ultra-low-noise frequency divider chain from 8 GHz to 5 MHz that utilizes custom-built regenerative frequency divide-by-2 circuits. The single-sideband (SSB) residual phase noise of this regenerative divider at 5 MHz output is -163 dBc/Hz

Vibrational analysis of stabilized lasers

May 24, 2012
Author(s)
Kenneth J. Hughes, Archita Hati, Craig W. Nelson, David A. Howe
Frequency-stabilized lasers are routinely used in a variety of research and application areas relating to laser-cooled atoms. Important applications in the cold-atom regime include atomic time keeping, inertial navigation, gravitational sensing, and

Characterizing Dynamic Effects of Oscillator Power Cycling

November 14, 2011
Author(s)
David A. Howe, Danielle G. Lirette, Neil Ashby, Archita Hati, Craig W. Nelson
We create a measurement technique and metrics consistent with easy interpretation to be used in development of new oscillators specifically for applications in which the oscillator’s power is turned on and off. This is useful in predicting the performance

Common-Arm Counter-Propagating Interferometer for Fiber Vibration Measurements

November 1, 2011
Author(s)
Craig W. Nelson, Archita Hati, David A. Howe
We propose and demonstrate a novel technique to measure the vibration sensitivity of two-port fiber-based optical components. It uses a common-arm counter-propagating frequency-shifted interferometer that cancels the vibration induced phase noise of the

5 MHz Phase Detector With Low Residual Flicker

September 15, 2011
Author(s)
Corey A. Barnes, Archita Hati, Craig W. Nelson, David A. Howe
The measurement of close-to carrier phase modulation (PM) noise of state-of-the-art oscillators is always challenging. Quite often the residual noise of the phase detector used in these measurements is the source of difficulty. In particular at Fourier

Limited Live-time Measurements of Frequency Spectra

July 31, 2011
Author(s)
David A. Howe, Neil Ashby, Danielle G. Lirette, Archita Hati, Craig W. Nelson
Frequency-difference-of-arrival (FDOA) can be used to monitor and track an emitter’s location by observing Doppler frequency shifts of the carrier during short pulsed transmissions. This specific application needs to consider two frequency-stability levels