Thin-film integrated band-rejection filters

The letter presents some design data for some new band-rejection (BR) filter configurations of the integrated exponential R-C-KR structure consisting of two nonuniform resistive films, one having per-unit-length (PUL) series resistance R(x)=R 0exp (kx) and the other KR(x), insulated from each other by a nonuniform dielectric film having PUL shunt capacitance C(r)=C0 exp (¿kx), where all the symbols have their standard meanings. It is shown that the frequencies of interest in the band-rejection region and the width of the band-rejection region may be controlled to suit designer´s requirements by suitable combination of the parameters K and k.