Compact Balanced Dual-Band Bandpass Filter Based on Modified Coupled-Embedded Resonators

A new compact balanced dual-band bandpass filter based on coupled-embedded resonators with modified ground plane is presented in this work. Common-mode is rejected within the two differential passbands by symmetrically introducing four coupled U-shaped defected ground structures below the resonators. Common-mode rejection is significantly improved when compared with the standard (solid ground plane) filter with similar geometry thanks to the introduction of four extra transmission zeros. Due to the symmetry, the differential mode is not significantly affected by the presence of the U-shaped resonators. Circuit-model data, full-wave simulations and measurements are provided to verify the benefits of the proposed dual-band filter.

[1]  Wei Kang,et al.  Dual-Band SIW Differential Bandpass Filter With Improved Common-Mode Suppression , 2015, IEEE Microwave and Wireless Components Letters.

[2]  Yindi Yao,et al.  A novel simple wideband common-mode suppression filter , 2014, IEICE Electron. Express.

[3]  Pei-Yuan Qin,et al.  Compact Balanced Dual- and Tri-band Bandpass Filters Based on Stub Loaded Resonators , 2015, IEEE Microwave and Wireless Components Letters.

[4]  Cheng-Ying Hsu,et al.  Design of Miniature Planar Dual-Band Filter Using Dual-Feeding Structures and Embedded Resonators , 2006, IEEE Microwave and Wireless Components Letters.

[5]  Jiasheng Hong,et al.  Couplings of microstrip square open-loop resonators for cross-coupled planar microwave filters , 1996 .

[6]  Jiasheng Hong.  Microstrip Filters for RF/Microwave Applications: Hong/Microstrip Filters 2E , 2011 .

[7]  Quan Xue,et al.  Balanced Bandpass Filters Using Center-Loaded Half-Wavelength Resonators , 2010, IEEE Transactions on Microwave Theory and Techniques.

[8]  Quan Xue,et al.  Dual-Band and Wide-Stopband Single-Band Balanced Bandpass Filters With High Selectivity and Common-Mode Suppression , 2010, IEEE Transactions on Microwave Theory and Techniques.

[9]  Jia-Sheng Hong,et al.  Microstrip Filters for RF Microwave Applications 2nd Edition , 2011 .

[10]  Pei-Yuan Qin,et al.  Compact Balanced Dual- and Tri-Band BPFs Based on Coupled Complementary Split-Ring Resonators (C-CSRR) , 2016, IEEE Microwave and Wireless Components Letters.

[11]  C.-I.G. Hsu,et al.  Balanced Dual-Band BPF With Stub-Loaded SIRs for Common-Mode Suppression , 2010, IEEE Microwave and Wireless Components Letters.

[12]  Jia-Sheng Hong,et al.  Dual-Band Differential Filter Using Broadband Common-Mode Rejection Artificial Transmission Line , 2013 .

[13]  Young-Ho Cho,et al.  Design of Balanced Dual-Band Bandpass Filters Using Asymmetrical Coupled Lines , 2013, IEEE Transactions on Microwave Theory and Techniques.

[14]  Quan Xue,et al.  Novel Balanced Dual-Band Bandpass Filter Using Coupled Stepped-Impedance Resonators , 2010, IEEE Microwave and Wireless Components Letters.

[15]  T. Itoh,et al.  A Novel Wideband Common-Mode Suppression Filter for Gigahertz Differential Signals Using Coupled Patterned Ground Structure , 2009, IEEE Transactions on Microwave Theory and Techniques.