Modeling of microstrip quasi-TEM superconducting transmission lines, comparison with experimental results

• Published in: Physica. C, Superconductivity Vol. 309; no. 1; pp. 71 - 78
• Main Authors: Boutboul, M.S., Kokabi, H., Pyée, M.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.12.1998; Elsevier Science
• Subjects: Applied sciences; Circuit properties; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electric, optical and optoelectronic circuits; Electronics; Exact sciences and technology; Microstrip; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; Microwave modeling; Occurrence, potential candidates; Physics; Quasi-TEM approach; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Superconducting devices; Superconductivity; Transition lines; YBaCuO; YBaCuO; Microstrip; Microwave modeling; Transition lines; Quasi-TEM approach; Surface impedance; Numerical method; TEM mode; Quasi-TEM mode; Modeling; Copper Oxides; Cut off frequency; Microstrip line; Phase velocity; Microwave line; Superconducting line; Barium Oxides; Quaternary compound; Yttrium Oxides; Insertion loss; Low pass filter; Propagation constant; Distributed parameter system
• ISSN: 0921-4534; 1873-2143
• DOI: 10.1016/S0921-4534(98)00545-0

In this paper the distributed parameters method is applied to model the propagation of microwave in a microstrip line of YBaCuO with different widths. This method is based on the two-fluid model and proceeds on an accurate evaluation of the expressions of the surface impedance ( R s+ jX s) and the propagation constant ( α+ jβ) in YBaCuO microstrip lines. We have considered not only the losses in the dielectric but also those in the metallic ground plane. This method has been validated on a 5.3 GHz cutoff frequency low pass filter, consisting of YBaCuO microstrip lines of small (190 μm) and large (2000 μm) width deposited on LaAlO 3 substrate. The match between experimental and simulation results is quite well from 60 to 89 K so the quasi-TEM approach is confirmed until 7 GHz. Moreover, a useful discussion has been carried out on the correction factors for fringe field effects in narrow microstrips.