Novel tunable band reject filter using RF MEMS technology

Abstract

A novel tunable band reject filter is designed and simulated using metamaterials and RF MEMS technology. CSRR on CPW line are used to achieve filter characteristics, while tunability is ensured through incorporation of a MEMS variable capacitor, enabling compatibility with planar IC technology. The CSRRs are etched on both the signal line and ground planes of the CPW with different CSRR structures. Tunability of the band reject filter is achieved by putting the MEMS bridge in either up or down state. The designed band stop filter rejection of stop bands are around -19.87 dB for down state around the centre frequency 29.719GHz and -17.96dB for up state around the centre frequency 33.172GHz. The proposed device structure is simulated using ANSOFT HFSS v13® for RF analysis.