Spectral domain analysis of three symmetric coupled lines and application to a new bandpass filter Academic Article uri icon


  • A quasi-static analysis and udetailed investigation are performed on three coupled, symmetric suspended striplines and microstriplines. The self and mutual capacitances of the structure, the per-unit-Iength capacitance matrix elements, and the three quasi-TEM mode per-unit-Iength capacitances are derived explicitly for the first time in terms of capacitances corresponding to arbitrary excitations. Normal mode characteristic impedance and effective dielectric constant data are presented. The mode impedances of the lines are found to be unequal for lines of equal width unlike previously reported. Chain matrix parameters for a new bandpass filter employing three coupled lines are derived. A filter with passband centered at 3 GHz has been designed, built, and tested, and measured performance shows good agreement with theoretically predicted performance. 1994 IEEE

published proceedings

  • IEEE Transactions on Microwave Theory and Techniques

author list (cited authors)

  • Schwindt, R., & Nguyen, C.

citation count

  • 34

complete list of authors

  • Schwindt, R||Nguyen, C

publication date

  • July 1994