Loading...

Modeling of Sub-wavelength Normal and Superconducting Nonuniform Transmission Lines in the Quasi-static Approximation

Mardy, Zahra | 2010

705 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 41195 (05)
  4. University: Sharif University of Technology
  5. Department: Electrical Engineering
  6. Advisor(s): Fardmanesh, Mahdi; Mehrany, Khashayar
  7. Abstract:
  8. In this thesis, we have investigated nonuniform normal and superconducting microstrip transmission lines in microwave regime. Photonic structures with subwavelength features can be homogenized and thus be accurately approximated by homogeneous structures. This idea is here applied to nonuniform transmission lines with subwavelength nonuniformities, i.e. subcentimeter features in the microwave regime. We present an analytical model based on telegraphers’ equations in order to obtain line propagation characteristics; characteristic impedance, propagation constant, and group velocity. The accuracy of analysis in normal and superconducting lines is evaluated by measurement and electromagnetic fullwave simulator results, respectively. In fact, we demonstrate that in a geometrically periodic NULT, if the nonuniformity period is small enough compared to wave length, the nonuniform line could be modeled by a uniform line such that the equivalent effective characteristic impedance is presented in a close form. Then, we show generally that a nonuniform transmission line could be analyzed by dividing it into smaller parts. This leads to an analytical approach for nonuniform microstrip transmission lines. The validity of the analytical model is confirmed through comparing simulation and measurement results
  9. Keywords:
  10. Nonuniform Transmission Line ; Superconductivity ; Microstrip Transmission Line ; Quasi-Transverse Electromagnetics Waves (Quasi-TEM) ; Telegrapher's Equation ; Sub-Wavelength Approximation

 Digital Object List

 Bookmark