Minimizing the variability of characteristic impedances in multisection quarter-wavelength transformers.

The widely used first-order polynomial representation of the voltage reflection coefficient in multisection quarter-wavelength transformers is assumed. The roots of this polynomial are displaced iteratively to obtain, through the simulated annealing technique, low variability between the characteristic impedances of adjacent transformers. Besides, for each problem configuration, the bandwidth is maintained close to its maximum possible value. An example is presented showing a decrease in the characteristic impedance variability of the transformers. ©1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 23: 194–196, 1999. [ABSTRACT FROM AUTHOR]