A New Microstrip Filter Using CRLH Structure and Defected Ground Structure in Antenna Application

Abstract

A new microstrip bandpass filter using composite right/left-handed (CRLH) mushroom structure with interdigital capacitors and defected ground structure (DGS) is proposed. The proposed filter uses CRLH mushroom structure working at its first negative resonance mode to create the passband and DGS to increase rejection outside the passband. Simulation and measurement results are in good agreement, and low in-band insertion loss and great out-band rejection have been achieved. It is demonstrated that the combination of CRLH mushroom structure with interdigital capacitors and DGS has succeeded in achieving excellent performance. This new filter can be applied in transmitting and receiving antennas.