Shunt series LC circuit for compact coplanar waveguide notch filter design

A shunt series LC resonant circuit based on an open version of an interconnected split ring resonator (OISRR) is proposed. This OISRR exhibits half the resonant frequency of the split ring resonator, allows a parallel connection with a coplanar waveguide (CPW) section and according to its frequency response is an attractive cell for compact CPW notch filter design. 3 dB stop-band bandwidth lower than 4.5% with more than 11 dB insertion loss in the stop-band can be achieved with a CPW loaded with a single OISRR. The experimental results have confirmed the possibilities of this OISRR, which can be easily connected to CPW antennas to reject undesirable signals.