Realization of Planar and SIW Filters with the Focus on Transmission Zero (TZ) and Evanescent-Mode Pole

• Author / Creator

  Nosrati, Mehdi

• With the recent progress in wireless and satellite communication and the 5G requirements for increased multi-band structures, integrated platforms with simple configurations are in need to offer flexibility in the design, selective pass-bands generation and/or unwanted frequencies suppression. In this connection, transmission zero realization is one of the most interesting concepts in the design of high frequency filters responsible for increasing attenuation and suppressing parasitic EM signals at specific frequencies. On the other hand, evanescent-mode technique is an alternative for miniaturization. Here, planar and 3D (waveguides) filters are studied with the focus on creating transmission zero and evanescent-mode pole. This thesis creates a bridge between the planar and 3D structures by expanding a comprehensive lumped element circuit modeling of distributed-element structures. The results have enhanced flexibility in the filter design with multiple notch-band realization, stop-band expansion and multi-band functionality using evanescent and ordinary modes excitation. For planar structures, the application of transmission zero is narrowed to notch-band realization to suppress the signal at some specific frequencies avoiding interference between local communication networks. Adopting the wave’s cancellation theory, multiple notches are realized in UWB BPFs using the higher spurious resonance frequencies of a resonator. In this connection, single-layer platforms are proposed to design UWB BPFs with multiple notch-band frequencies. In addition, the concept is further studied to develop tunable multiple notch-band UWB BPFs where a new configuration of coplanar waveguide multi-mode resonator integrated with MEMS capacitor is developed for single/double notch-band realization. Moreover, the importance of such analysis is highlighted in 3D structures integrated with new L-shaped irises and open side walls. The proposed integration is more studied using lumped element equivalent circuits to conceptually discuss the behavior of distributed-element structures resulting in the complete analysis and control of these components. Furthermore, a prescribed filtering function is demonstrated using the lumped element analysis including not only evanescent-mode pole, but also close-in transmission zero.

• Subjects / Keywords

  • Evanescent-mode pole
  • Transmission zero
  • Bandpass filter

• Graduation date

  Fall 2017

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R3DR2PP43

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.