Full-wave analysis of superconducting microstrip lines on anisotropic substrates using equivalent surface impedance approach

Journal Article · Wed Dec 01 04:00:00 EST 1993 · IEEE Transactions on Microwave Theory and Techniques (Institute of Electrical and Electronics Engineers); (United States)

DOI:https://doi.org/10.1109/22.260729· OSTI ID:7270500

Lee, L H; Lyons, W G; Orlando, T P; Ali, S M ^[1]; Lyons, W G ^[2]; Withers, R S ^[3]

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1. Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Electrical Engineering and Computer Science
2. Massachusetts Inst. of Tech., Lexington, MA (United States). Lincoln Lab.
3. Conductus, Inc., Sunnyvale, CA (United States)

A computationally efficient full-wave technique is developed to analyze single and coupled superconducting microstrip lines on anisotropic substrates. The optic axis of the dielectric is in the plane of the substrate at an arbitrary angle with respect to the propagation direction. A dyadic Green's function for layered, anisotropic media is used to formulate an integral equation for the current in the strips. To increase the efficiency of the method, the superconducting strips are replaced by equivalent surface impedances which account for the loss and kinetic inductance of the superconductors. The validity of this equivalent surface impedance (ESI) approach is verified by comparing the calculated complex propagation constant and characteristic impedance for superconducting microstrip lines on an isotropic substrate to measured results, and to numerical results by the more rigorous volume-integral equation method. The results calculated using the ESI approach for perfectly conducting coupled lines on an anisotropic substrate agree with the results by the finite-difference time-domain method. This efficient ESI technique is then used to study the effects of the optic axis orientation and the strip width on the characteristics of single and coupled superconducting microstrip lines on M-plane sapphire. The effects of the line separation and operating temperature on the coupled lines are also investigated.

• OSTI ID: 7270500
• Journal Information: IEEE Transactions on Microwave Theory and Techniques (Institute of Electrical and Electronics Engineers); (United States), Journal Name: IEEE Transactions on Microwave Theory and Techniques (Institute of Electrical and Electronics Engineers); (United States) Vol. 41:12; ISSN IETMAB; ISSN 0018-9480
• Country of Publication: United States
• Language: English

Related Subjects

665412* -- Superconducting Devices-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CALCULATION METHODS
DIELECTRIC PROPERTIES
ELECTRICAL PROPERTIES
ELECTRONIC EQUIPMENT
EQUIPMENT
MATHEMATICS
MICROWAVE EQUIPMENT
NUMERICAL ANALYSIS
PERFORMANCE
PHYSICAL PROPERTIES
SUPERCONDUCTING DEVICES