Ultra-compact microwave filters using kinetic inductance microstrip

Conference · Fri Mar 01 04:00:00 EST 1991 · IEEE Transactions on Magnetics (Institute of Electrical and Electronics Engineers); (United States)

OSTI ID:6088975

Pond, J M; Carroll, K R; Cukauskas, E J ^[1]

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1. Microwave Technology Branch, Naval Research Lab., Washington, DC (US)

This paper reports on multi-pole microwave filters designed and fabricated using microstrip transmission line sections which consist of two very thin films of sputtered niobium nitride (NbN) separated by another very thin film of sputtered Si. Since the thicknesses of all three films are much less than the superconducting penetration depth, the kinetic inductance is significantly greater than the magnetic inductance. As a result, the phase velocity of a microstrip transmission line is much less than the free space speed of light. Since resonant structures are reduced in size proportionately, the size and weight of microstrip circuits can be greatly reduced. Prototype filters consisting of four open circuit half-wavelength microstrip stubs separated by full-wavelength microstrip sections have been measured. The circuits are connected to 34 mil diameter coaxial cable via an intermediate coplanar waveguide section. Passbands of 4 GHz separated by 3 GHz reject bands have been measured in a structure which occupies less than 0.5 cm{sup 2} including the coplanar waveguide transitions. Higher-order passbands, although possessing an increased insertion loss, maintain filter passband characteristics through 20.0 GHz.

• OSTI ID: 6088975
• Report Number(s): CONF-900944--
• Conference Information: Journal Name: IEEE Transactions on Magnetics (Institute of Electrical and Electronics Engineers); (United States) Journal Volume: 27:2
• Country of Publication: United States
• Language: English

Related Subjects

665411 -- Basic Superconductivity Studies-- (1992-)
665412* -- Superconducting Devices-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CABLES
COAXIAL CABLES
CONDUCTOR DEVICES
DESIGN
ELECTRIC CABLES
ELECTRIC CONDUCTIVITY
ELECTRICAL EQUIPMENT
ELECTRICAL PROPERTIES
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY LOSSES
EQUIPMENT
FILMS
FILTERS
LOSSES
MICROWAVE POWER TRANSMISSION
MICROWAVE RADIATION
NIOBIUM COMPOUNDS
NIOBIUM NITRIDES
NITRIDES
NITROGEN COMPOUNDS
PENETRATION DEPTH
PHASE VELOCITY
PHYSICAL PROPERTIES
PNICTIDES
POWER TRANSMISSION
RADIATIONS
REFRACTORY METAL COMPOUNDS
SEMIMETALS
SILICON
SIZE
SPUTTERING
SUPERCONDUCTING FILMS
SUPERCONDUCTIVITY
TRANSITION ELEMENT COMPOUNDS
VELOCITY
WAVELENGTHS