Analysis of Scattering Parameters of Finite Stealthy Transmission Line

In this paper, two finite transmission lines loaded with open-ended stubs distributed in different ways are compared and studied. The first structure is a periodically loaded transmission line with open-ended stubs. For the second structure the loading is no longer periodic, but the locations of the stubs are calculated based on an optimization procedure in the reciprocal Fourier space. The locations are chosen such that the amplitude of spatial Fourier transform vanishes for frequency ranges near the first stop-band. The newly proposed transmission line has an increase in bandwidth and a reduction in ripple in the transmission coefficient, but the ripple is present throughout the whole pass-band.