Compact Second-Order Bandstop Filter Based on Dual-Mode Complementary Split-Ring Resonator

A compact dual-mode bandstop filter is presented in this letter. From an equivalent circuit viewpoint, a second-order response is obtained by designing a two-pole notch filter with inductive coupling. This equivalent circuit is then implemented by using a dual-mode complementary-split-ring resonator. The proposed bandstop filter prototype has dimensions of 0.1λ<sub>g</sub> × 0.18λ<sub>g</sub>, where λ<sub>g</sub> defines the guided-wave wavelength. An experimental validation at the center frequency f<sub>0</sub> of 2 GHz shows that the proposed filter can extend the harmonic-free upper passband up to 4.2f<sub>0</sub>.

[1]  K. Divyabramham,et al.  Compact Wideband Bandstop Filter With Five Transmission Zeros , 2012, IEEE Microwave and Wireless Components Letters.

[2]  Wael M Fathelbab,et al.  Two Novel Classes of Band-Reject Filters Realizing Broad Upper Pass Bandwidth—Synthesis and Design , 2011, IEEE Transactions on Microwave Theory and Techniques.

[3]  S. Sanyal,et al.  Compact, Wideband Bandstop Filters With Sharp Rejection Characteristic , 2008, IEEE Microwave and Wireless Components Letters.

[4]  Gabriel M. Rebeiz,et al.  Lumped-Element Fully Tunable Bandstop Filters for Cognitive Radio Applications , 2011, IEEE Transactions on Microwave Theory and Techniques.

[5]  Jia-Sheng Hong,et al.  Wideband Bandstop Filter With Cross-Coupling , 2007, IEEE Transactions on Microwave Theory and Techniques.

[6]  I. Gil,et al.  Microwave filters with improved stopband based on sub-wavelength resonators , 2005, IEEE Transactions on Microwave Theory and Techniques.

[7]  Derek Abbott,et al.  Dual-mode behavior of the complementary electric-LC resonators loaded on transmission line: Analysis and applications , 2014 .

[8]  F. Medina,et al.  Common-Mode Suppression in Microstrip Differential Lines by Means of Complementary Split Ring Resonators: Theory and Applications , 2012, IEEE Transactions on Microwave Theory and Techniques.

[9]  Gabriel M. Rebeiz,et al.  Tunable 500–1200-MHz Dual-Band and Wide Bandwidth Notch Filters Using RF Transformers , 2015, IEEE Transactions on Microwave Theory and Techniques.

[10]  R.V. Snyder,et al.  Bandstop filters with extended upper passbands , 2006, IEEE Transactions on Microwave Theory and Techniques.

[11]  D. Abbott,et al.  Compact Dual-Mode Wideband Filter Based on Complementary Split-Ring Resonator , 2014, IEEE Microwave and Wireless Components Letters.

[12]  D. Peroulis,et al.  Extended Passband Bandstop Filter Cascade With Continuous 0.85–6.6-GHz Coverage , 2012, IEEE Transactions on Microwave Theory and Techniques.

[13]  Javier Mata-Contreras,et al.  Modeling and Applications of Metamaterial Transmission Lines Loaded With Pairs of Coupled Complementary Split-Ring Resonators (CSRRs) , 2016, IEEE Antennas and Wireless Propagation Letters.

[14]  Juseop Lee,et al.  Frequency Response Control in Frequency-Tunable Bandstop Filters , 2010, IEEE Microwave and Wireless Components Letters.