Flux-flow-type Josephson oscillator for millimeter and submillimeter wave region. III. Oscillation stability

Journal Article · Mon Jul 01 04:00:00 EDT 1985 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.335643· OSTI ID:5784685

Nagatsuma, T; Enpuku, K; Sueoka, K; Yoshida, K; Irie, F

Numerical as well as experimental studies have been made of the oscillation stability for the travelling-wave-type oscillator, which utilizes a vortex motion in a long Josephson junction, i.e., a flux flow. For the Josephson oscillator, a steep current step in a dc I-V characteristic improves the oscillation stability. Two kinds of effects which degrade the steepness of the current step have been investigated for the long junction of the overlap geometry. One is the self-field effect which makes the current step inclined, and the other is the resonant motion of the vortices which induces a staircaselike structure on the current step. We have discussed the method for the reduction of these effects and proposed a novel junction geometry without these effects, i.e., an overlap junction with a projection on one junction side. With the new geometry, we have obtained current steps whose slope is about one hundred times steeper than those obtained with the conventional overlap geometry and whose height attains about a half of the maximum critical current over the wide voltage region 0.1< or =V/sub dc/< or =1.0 mV. The linewidth calculated from the current step is expected to be a few kHz.

• Research Organization: Department of Electronics, Kyushu University 36, Fukuoka 812, Japan
• OSTI ID: 5784685
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 58:1; ISSN JAPIA
• Country of Publication: United States
• Language: English

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420201* -- Engineering-- Cryogenic Equipment &amp; Devices
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTROMAGNETIC RADIATION
ELECTRONIC EQUIPMENT
EQUIPMENT
FAR INFRARED RADIATION
INFRARED RADIATION
JOSEPHSON JUNCTIONS
JUNCTIONS
MICROWAVE RADIATION
OSCILLATORS
PHYSICAL PROPERTIES
RADIATIONS
STABILITY
SUPERCONDUCTING JUNCTIONS