λ/4 CPS interdigital bandpass filter

There are many properties such as small dispersion, small to moderate loss, and insensitive to substrate thickness in uniplanar transmission lines. Shunt mounted devices can have no via-holes in uniplanar transmission lines so that the via-hole´s parasitic inductance is also eliminated. Due to the mentioned advantages, uniplanar transmission lines such as CPW and CPS are attractive structures for planar microwave circuit applications where filter is one of them. In this paper, a new structure for lambda/4 CPS interdigitial filter is proposed. A five-pole lambda/4 CPS interdigital bandpass filter with Chebyshev response is realized, and the experimental performances agree well with the stimulated results. The proposed lambda/4 CPS interdigitial filter is suitable for uniplanar and balanced circuit. Due to the parallel filter structure, it can reduce the filter in size and realize various filter configurartions.