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Search Publications by: David A. Howe (Assoc)

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Displaying 76 - 100 of 246

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

Residual PM Noise Evaluation of Radio Frequency Mixers

July 31, 2011
Author(s)
Corey A. Barnes, Archita Hati, Craig W. Nelson, David A. Howe
Direct observation of phase modulated (PM) noise is often difficult due to the high dynamic range that exists between the carrier and the modulated sidebands. A common tool used to reduce the dynamic range is the phase detector, which removes the carrier

Vibration Sensitivity of Optical Components: A Survey

July 31, 2011
Author(s)
Archita Hati, Craig W. Nelson, 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

Fast TheoBR: A method for long data set stability analysis

September 1, 2010
Author(s)
Jennifer A. Taylor, David A. Howe
TheoBR (Theo1 with Bias Removed) is a high-confidence statistic that evaluates frequency stability at long \tau values. However, for real-world data sets that are thousands of points and longer, the calculation of the bias with respect to the Allan

High Spectral purity oscillator at 40 GHz: Design using air-dielectric Cavity

June 2, 2010
Author(s)
Archita Hati, Craig W. Nelson, Billy F. Riddle, David A. Howe
We describe the design of a low-PM noise 40 GHz oscillator that uses a conventional air-dielectric cavity resonator as a frequency discriminator to clean up the PM noise of a commercial 10 GHz dielectric resonator oscillator (DRO) multiplied by four. The

Phase noise suppression in frequency comb generators

June 2, 2010
Author(s)
Craig W. Nelson, Archita Hati, J F. Nava-garcia, David A. Howe
We propose an idea to suppress the flicker (1/f) noise in radio frequency (RF) multiplier based frequency comb generators. Comb generators are often used for frequency multiplication in frequency synthesis. In general, comb generators apply high power to a

Phase-lock Loops in Vibration Environments

November 16, 2009
Author(s)
Archita Hati, Craig W. Nelson, David A. Howe
A popular scheme for achieving low phase noise across a large range of offset frequencies is to employ an oscillator at an output frequency with low far-from-carrier noise that is phase-locked to a reference that has low close-to-carrier noise. We

Vibration-induced PM and AM noise in microwave components

October 1, 2009
Author(s)
Archita Hati, Craig W. Nelson, David A. Howe
The performance of microwave components is sensitive to vibrations to some extent. Among them, microwave cables and connectors, bandpass filters, mechanical phase shifters and some non-linear components are the most sensitive. The local oscillator is one

Vibration-induced PM noise in oscillators and its suppression

January 1, 2009
Author(s)
Archita Hati, Craig W. Nelson, David A. Howe
High precision oscillators have significant applications in modern communication and navigation systems, radars, and sensors mounted in unmanned aerial vehicles, helicopters, missiles, and other dynamic platforms. These systems must provide their required

Vibration-induced PM Noise of A Rigid Optical Fiber Spool

December 1, 2008
Author(s)
Jennifer A. Taylor, Craig W. Nelson, Archita Hati, Neil Ashby, David A. Howe
Oscillators operating in field applications are subject to much more strenuous environmental effects than those in the laboratory. These environmental effects, like vibration and temperature fluctuation, have a great impact on the performance of the

Cancellation of Vibration-Induced Phase Noise in Optical Fibers

November 15, 2008
Author(s)
Archita Hati, Craig W. Nelson, Jennifer A. Taylor, David A. Howe
Vibration causes mechanical distortions in fiber-optic transmission lines that induce phase fluctuations. A scheme is described which enables electronic cancellation of vibration-induced phase noise in an optical fiber wound on a spool. We report 20 dB or

Relative Intensity Noise Suppression for Photonic Links

September 15, 2008
Author(s)
Craig Nelson, Archita Hati, David A. Howe
We propose and experimentally demonstrate a novel technique to reduce laser relative intensity noise (RIN). A RIN suppression servo is usually implemented by inserting an intensity modulator in the optical path and controlling measured light intensity with