88 citations · 207 across the 8 of their papers we have counts for
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Resonator Power to Frequency Conversion in a Cryogenic Sapphire Oscillator
Nitin R. Nand, Stephen R. Parker, Eugene N. Ivanov +3
We report on the measurement and characterization of power to frequency conversion in the resonant mode of a cryogenic sapphire loaded cavity resonator, which is used as the freque…
Comparison of ultra-stable radio frequency signals synthesized from independent secondary microwave frequency standards
John G. Hartnett, Stephen R. Parker, Eugene N. Ivanov +3
The phase noise and frequency stability measurements of 1 GHz, 100 MHz, and 10 MHz signals are presented which have been synthesized from microwave cryogenic sapphire oscillators u…
Ultra-low-phase-noise cryocooled microwave dielectric-sapphire-resonator oscillators with 1 x 10^-16 frequency instability
John G. Hartnett, Nitin R. Nand, Chuan Lu
Two nominally identical ultra-stable cryogenic microwave oscillators are compared. Each incorporates a dielectric-sapphire resonator cooled to near 6 K in an ultra-low vibration cr…
Ultra stable and very low noise signal source using a cryocooled sapphire oscillator for VLBI
Nitin R. Nand, John G. Hartnett, Eugene N. Ivanov +1
Here we present the design and implementation of a novel frequency synthesizer based on low phase noise digital dividers and a direct digital synthesizer. The synthesis produces tw…
Cryogenic Sapphire Oscillator using a low-vibration design pulse-tube cryocooler: First results
John G. Hartnett, Nitin R. Nand, Chao Wang +1
A Cryogenic Sapphire Oscillator has been implemented at 11.2 GHz using a low-vibration design pulse-tube cryocooler. Compared with a state-of-the-art liquid helium cooled CSO in th…
Ultra-low vibration pulse-tube cryocooler stabilized cryogenic sapphire oscillator with 10^-16 fractional frequency stability
John G. Hartnett, Nitin R. Nand
A low maintenance long-term operational cryogenic sapphire oscillator has been implemented at 11.2 GHz using an ultra-low-vibration cryostat and pulse-tube cryocooler. It is curren…