Resonator and bandpass filter using CRLH transmission line based on microstrip-coplanar-waveguide structure

A novel miniaturized resonator and bandpass filter configuration that employs dual-plane (microstrip/coplanar waveguide structure) composite right/left-handed transmission line (CRLH-TL) are proposed. The series capacitance of CRLH-TL unit cell is realized by metal-insulator-metal (MIM) capacitor implemented by the parallel microstrip lines on the upper layer of the substrate and the CPW on the ground plane. The shunt inductance of unit cell is provided by a shorted meander line stub on the lower metal layer. It is via-free and low-loss. In comparison with the conventional CRLH-TL resonator, the proposed resonator offers 3 times size reduction.