Wide-Stopband SIW Filters Using Modified Multi-Spurious Modes Suppression Technique

A modified multi-spurious modes suppression technique is proposed to realize wide-stopband substrate-integrated waveguide (SIW) bandpass filters (BPFs), which is to set the external ports and internal coupling windows to the positions of weakest electric fields of specific spurious modes. To extend the stopband as wide as possible with the limited design degrees of freedom, different feeding and coupling positions are fully exploited to reject unwanted modes in specific cavities. By suppressing the out-of-band spurious peaks as much as possible and removing the first unsuppressed spurious resonance to the farthest position, the widest stopband can be achieved intrinsically. A second- and a third-order SIW BPFs are synthesized, designed, fabricated, and tested as demonstrations, realizing the stopbands of <inline-formula> <tex-math notation="LaTeX">$2.51{f} _{0}$ </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">$3.85{f} _{0}$ </tex-math></inline-formula> with the rejection level better than 25 dB and 20 dB, respectively.

[1]  Jian-Xin Chen,et al.  Compact Multi-Layer Bandpass Filter With Wide Stopband Using Selective Feeding Scheme , 2018, IEEE Transactions on Circuits and Systems II: Express Briefs.

[2]  Quanyuan Feng,et al.  Multilayer Substrate Integrated Waveguide (SIW) Filters With Higher-Order Mode Suppression , 2016, IEEE Microwave and Wireless Components Letters.

[3]  V Sekar,et al.  A 1.2–1.6-GHz Substrate-Integrated-Waveguide RF MEMS Tunable Filter , 2011, IEEE Transactions on Microwave Theory and Techniques.

[4]  W. Yin,et al.  Novel Substrate Integrated Waveguide Filters With Mixed Cross Coupling (MCC) , 2009, IEEE Microwave and Wireless Components Letters.

[5]  Shao Yong Zheng,et al.  High-Isolation and Wide-Stopband SIW Diplexer Using Mixed Electric and Magnetic Coupling , 2020, IEEE Transactions on Circuits and Systems II: Express Briefs.

[6]  Mehdi Salehi,et al.  Spurious‐response suppression of substrate integrated waveguide filters using multishape resonators and slotted plane structures , 2011 .

[7]  Akhilesh Mohan,et al.  Substrate Integrated Waveguide Dual-Band and Wide-Stopband Bandpass Filters , 2018, IEEE Microwave and Wireless Components Letters.

[8]  Jin Young Kim,et al.  Harmonics suppressed substrate‐integrated waveguide filter with integration of low‐pass filter , 2008 .

[9]  Kamran Entesari,et al.  Ultra-Miniature SIW Cavity Resonators and Filters , 2015, IEEE Transactions on Microwave Theory and Techniques.

[10]  Wei Hong,et al.  Wide stopband substrate integrated waveguide filter using corner cavities , 2013 .

[11]  Maurizio Bozzi,et al.  Substrate Integrated Folded Waveguide Filter with Out-of-Band Rejection Controlled by Resonant-Mode Suppression , 2015, IEEE Microwave and Wireless Components Letters.

[12]  Jia-Sheng Hong,et al.  Microstrip filters for RF/microwave applications , 2001 .

[13]  Zhenya Lei,et al.  A Novel Miniature Single-Layer Eighth-Mode SIW Filter With Improved Out-of-Band Rejection , 2018, IEEE Microwave and Wireless Components Letters.

[14]  Lin Li,et al.  Compact cross-coupled circular cavity filters using multilayer substrate integrated waveguide , 2009 .

[15]  Jun-Fa Mao,et al.  Design of multilayer triangular substrate integrated waveguide filter in LTCC , 2009 .

[16]  Akhilesh Mohan,et al.  A compact sixteenth‐mode substrate integrated waveguide bandpass filter with improved out‐of‐band performance , 2017 .

[17]  Wen Wu,et al.  Resonance Characteristics of Substrate-Integrated Rectangular Cavity and Their Applications to Dual-Band and Wide-Stopband Bandpass Filters Design , 2017, IEEE Transactions on Microwave Theory and Techniques.

[18]  Wen Wu,et al.  Substrate integrated waveguide dual-band filter with wide-stopband performance , 2017 .

[19]  Vakur B. Erturk,et al.  SIW‐based interdigital bandpass filter with harmonic suppression , 2015 .