TUNABLE SUPERCONDUCTIVE RF NETWORKS.
Quarterly rept. no. 1, 1 Jul-30 Sep 65,
AIRBORNE INSTRUMENTS LAB DEER PARK NY
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Efforts concern a program having as its objective-research and development on tunable superconductive RF networks, and fabrication and delivery of two exploratory development models of tunable superconductive narrow-band preselectors in open dewars. An extensive circuit analysis was carried out. Some of the results are the transformer-coupled filter configuration offers promise due to independent bandwidth and frequency controls the equal-element filter is the best filter design identical transformer and capacitor elements can be used to simplify tracking lines connecting individual superconducting filter elements could be at room temperature, if desired, to simplify the design. In the tracking study, several capacitor geometries were studied and their calculated variations of capacitance with displacement error was compared. Several superconducting circuits were tested. A combination niobium stannide and lead superconducting circuit yielded a measured unloaded Q of 250,000 at 4.2 K and 710,000 at 1.7 K in a measurement of 9.85 mc. Sapphire and quartz supports were found to yield reduced Qs inversely proportional to dielectric constant. Author
- Electrical and Electronic Equipment