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Search Publications by: Archita Hati (Fed)

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Displaying 26 - 50 of 177

Optically referenced broadband electronic synthesizer with 15 digits of resolution

September 5, 2016
Author(s)
Franklyn J. Quinlan, Tara M. Fortier, A. Rolland, Frederick N. Baynes, A. J. Metcalf, Archita Hati, Andrew D. Ludlow, Nathan M. Hinkley, M. Shimizu, Joe Campbell, Scott A. Diddams
Increasing demands in the high tech industry for higher data rates and better synchronization necessitates the development of new wideband and tunable sources with improved noise performance over traditional synthesis based quartz oscillators. Precision

Measurement of AM-to-PM Conversion in a Quartz-MEMS Resonator

May 9, 2016
Author(s)
Craig W. Nelson, Archita Hati, David A. Howe
This work investigates the new aspects of the non-linear response in a quartz-MEMS resonator at 635 MHz. We characterize its major cause of AM-to-PM conversion as a function of power and drive frequency; this is important in developing noise compensation

Power Splitter Thermal Noise Correlations in Cross-spectrum Noise Measurements

May 9, 2016
Author(s)
Archita Hati, Craig W. Nelson, David A. Howe
We discuss collapse of the cross-spectrum phase noise measurement of thermally-limited oscillator due to anti-correlated thermal noise of the Wilkinson power splitter. We also examine effect of thermal noise of various resistive power splitters on such

Practical Evaluation of a 50 km Fiber Link Utilizing a Commercial Modem

May 9, 2016
Author(s)
Corey A. Barnes, Archita Hati, Craig W. Nelson, David A. Howe
We evaluate the stability of two-way time and frequency transfer over a 50 km fiber optic link established using a commercially available fiber optic modem. For this evaluation we report the residual phase noise, total Allan deviation, total time deviation

Cross-spectral Collapse from Anti-correlated Thermal Noise in Power Splitters

April 4, 2016
Author(s)
Craig Nelson, Archita Hati, David A. Howe
We discuss the cross-spectral collapse due to anti-correlated thermal noise that originates from the common-mode power divider (splitter) in a cross-spectrum noise measurement system. We studied this effect for different power splitters and discuss its

Oscillator PM-noise reduction from correlated AM-noise

March 11, 2016
Author(s)
Archita Hati, Craig W. Nelson, David A. Howe
We demonstrate a novel technique for reducing the phase modulation (PM) noise of an oscillator in steady state as well as under vibration. It utilizes correlation between PM noise and amplitude modulation (AM) noise that can originate from the oscillator's

Cross-spectrum Measurement of Thermal-noise Limited Oscillators

March 1, 2016
Author(s)
Archita Hati, Craig W. Nelson, David A. Howe
Cross-spectrum analysis is a commonly-used technique for the detection of phase and amplitude noise of a signal in the presence of interfering noise. It extracts the desired correlated noise from two time series which also contain uncorrelated interfering

Optical-to-RF Frequency Synthesis: Application Priorities for Ultra-low Phase Noise

October 18, 2015
Author(s)
David A. Howe, Archita Hati, Craig W. Nelson, Lora L. Nugent-Glandorf
We describe operational challenges and progress of optical frequency-comb dividers (OFDs) that synthesize RF signals from the optical domain. Our priorities include: (1) ultra-low phase-noise, (2) continuous operation, and (3) broadly low Allan deviation.

PM Noise Measurement at W-Band

December 12, 2014
Author(s)
Archita Hati, Craig W. Nelson, David A. Howe
We present improved performance for a 92 - 96 GHz cross-spectrum phase modulated (PM) noise measurement system previously reported. The system is principally designed to measure amplifiers in pulsed mode with a duty cycle of 10% to 100% (CW) at a given

A 40 GHz Air-Dielectric Cavity Oscillator with Low Phase Modulation

September 1, 2014
Author(s)
Archita Hati, Craig W. Nelson, Billy F. Riddle, David A. Howe
We describe the design of a low-phase modulated (PM) noise, 40 GHz oscillator that uses a conventional air-dielectric cavity resonator as a frequency discriminator to improve the PM noise of a commercial 10 GHz dielectric resonator oscillator (DRO)

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