Coplanar Waveguide

2010.10.30 Takuichi Hirano

Input

Dielectric constant
A half width of signal line a mm
Distance from the center to the slot edge of the ground b mm
Thickness of conductor t mm
Thickness of substrate h mm

Output

Characteristic impedance Z0 Ohms
Effective relative permittivity

 

([2])

([2])

(Eq.(4) in [1])

for finite metallization thickness ([2])

(filling factor; Eq.(5b) in [1])

where, K(m) is the complete elliptic integral of the first kind.

(Eq.(5a) in [1])
for finite metallization thickness ([2])

(Eq.(6) in [1])

References
  1. G. Ghione, C.U. Naldi, "Coplanar Waveguides for MMIC Applications: Effect of Upper Shielding, Conductor Backing, Finite-Extent Ground Planes, and Line-to-Line Coupling," IEEE Transactions on Microwave Theory and Techniques, Vol.35, No.3, pp.260-267, March 1987.
  2. K. C. Gupta, R. Garg, I. J. Bahl, and P. Bhartia, Microstrip Lines and Slotlines, 2nd ed.Artech House, Inc., 1996.
Appendix

Download Mathematica Notebook File: cpw.nb (49KB)

Copyright(c) 2010 Takuichi Hirano

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