Novel topology of compact coplanar waveguide resonant cell low‐pass filter

In this study, a novel pseudoelliptic function low‐pass filter (LPF) constituted by a compact coplanar waveguide resonant cell has been designed and manufactured. The lumped‐element seven‐pole prototype has been adequately realized by using complementary perturbations located both in signal line and ground plane metallization. The fabricated uniplanar LPF offers a compact size of 5.6 × 9.8 mm2, return loss better than −26 dB over the passband, stop‐band rejection better than 27 dB up to 8 GHz and a narrow transition band. The experimental results are in agreement with theoretical characteristics. The solution proposed is superior to the classic semilumped element counterpart in the level of length reduction (67% of abbreviation).