Investigation of tapered multiple microstrip lines for VLSI circuits.

The S-parameters of coupled, tapered microstrip lines are calculated as a function of frequency using an iteration-perturbation technique. Each tapered microstrip line is analyzed by dividing the line into small segments so that each segment can be approximated as a uniform line. For each frequency, starting with the static case, the effective dielectric constant, ε_r/eff, is determined. This value is then used to compute the characteristic impedance of that section of line and the S-parameters are obtained using standard microwave analysis. The S-matrix is converted into a T-matrix, and since the sections are cascaded, all T-matrices are multiplied to drive a final T-matrix. This final T-matrix is then converted into an S-matrix, which is frequency dependent, and the mismatch introduced by the taper is obtained from the S-matrix.