диафрагмированные волноводные фильтры / b5cf1bc8-3ac8-479f-a0be-9b88a9b105c3

Fig. 28. Broadband measurement of the second prototype.

itself an advanced design exploiting nonresonating modes and nonresonating nodes (state-of-the-art of microwave filter design). Besides the obvious size reduction (roughly 50%), the new SWC filter attained superior electrical performance for both passband insertion loss and stopband attenuation, as well as a significantly larger extent of the upper stopband.

VI. CONCLUSION

A new class of reduced-size waveguide filters based on SWC structures has been introduced in this article. The SWC has been proposed and analyzed in both singleand doublestub configurations. The design and implementation of higher order filters employing multiple SWCs and a combination of SWCs with conventional waveguide cavities have been proposed and experimentally validated. The obtained results demonstrate that this new class of filters based on SWCs represents indeed a very competitive solution which, for certain specifications (such as the one reported in this article), is capable of outperforming even some of the most advanced filter realizations.

Fig. 29. Size comparison between the (a) new SWC filter and (b) its predecessor published in [17].

penetrate, the cavity modes move lower in frequency); finally, as is for any common waveguide filter, the irises are also tuned by using small diameter screws (as the screws penetrate, the effective coupling increases). The experimental results of the fabricated filter are shown in Fig. 27. The measured insertion loss is 0.5 dB at f0, 0.61 dB at the lower passband frequency (31.10 GHz), and 1.71 dB at the upper edge of the passband (31.25 GHz), corresponding to experimental Q-factors of about 3600 for the TE201 in the main cavities, 3200 for the TM110 mode in the stubs, and 3200 for the TE101 mode in the interconnecting cavity. These numbers (naturally, including the effect of the tuning elements) are consistent with a typical 60%–70% efficiency with respect to the theoretical unloaded Q-factors, which for this design would be 5050 for the TE201 mode, and 4500 for the TM110 and TE101 modes. Fig. 28 shows a broadband measurement of the filter, where the upper spurious free stopband extends up to 38 GHz.

Finally, Table I shows a performance comparison between this new SWC filter and its predecessor filter presented in [17]. Fig. 29 shows a photograph of the two filters next to each other. Observe that the original filter presented in [17] is

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Simone Bastioli (S’10–M’11–SM’18) received the Ph.D. degree in electronic engineering from the University of Perugia, Perugia, Italy.

In 2005, he was an Intern with Ericsson AB, Mölndal, Sweden, where he was involved with the design of waveguide filters and transitions for commercial RF applications. In 2009, he was with RF Microtech Srl, Perugia, where he was responsible for the design of advanced microwave filters for private and European Space Agency (ESA) funded projects. In 2010, he joined RS Microwave, Inc.,

Butler, NJ, USA, where he is currently the Acting Chief Engineer responsible for the design and development of innovative microwave filters, multiplexers, and switched filters banks, as well as more complex sub-assemblies for military and space applications. His work has resulted in several publications published in international journals and conferences, as well as several patent applications.

IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES

Dr. Bastioli was a recipient of the 2012 IEEE Microwave Prize for the invention of TM dual-mode cavities with nonresonating modes. In 2018, he was awarded the IEEE Outstanding Young Engineer Award. He is currently serving as an IEEE MTT-S Distinguished Microwave Lecturer (DML). In 2008, he was awarded the Best Student Paper Award (First Place) at the IEEE MTT-S International Microwave Symposium (IMS), Atlanta, GA, USA, and the Young Engineers Prize at the European Microwave Conference, Amsterdam, The Netherlands. He is currently the Chair of the technical committee MTT-5 (Filters), and he serves as an Associate Editor of IEEE Microwave Magazine.

Richard V. Snyder (S’58–M’63–SM’80–F’97– LF’05) received the B.S. degree from LoyolaMarymount University, Los Angeles, CA, USA, the M.S. degree from the University of Southern California, Los Angeles, CA, USA, and the Ph.D. degree from the Polytechnic Institute of New York University, Brooklyn, NY, USA.

He is currently the President of RS Microwave, Butler, NJ, USA, which was founded in 1981. He teaches and advises at the New Jersey Institute of Technology. He is a Visiting Professor with The

University of Leeds, Leeds, U.K. He has authored or coauthored 126 articles and 3 book chapters, and holds 26 patents. His current research interests include electromagnetic simulation, network synthesis, dielectric and suspended resonators, high-power notch and bandpass filters, and active filters.

Dr. Snyder is currently a member of the American Physical Society, the AAAS, and the New York Academy of Science. He was a two-time recipient of the Region 1 Award. He was a recipient of the IEEE Millennium Medal in 2000. He served as the Chairman and the Chair for the IEEE MTT-AP Chapter for 14 years and the IEEE North Jersey EDS and CAS Chapters for 10 years. He was the General Chairman for IMS2003, Philadelphia, PA, USA, and he was the Emeritus Chair of IMS2018, Philadelphia, PA, USA. He was elected to the AdCom in 2004. Within the AdCom, he served as a Chair for the TCC and Liaison to the EuMA. He served as an IEEE MTT-S Distinguished Lecturer from 2007 to 2010, continuing as a member for the Speakers Bureau, and an Associate Editor for the IEEE TRANSACTIONS ON MICROWAVE THE- ORY AND TECHNIQUES, responsible for most of the filter articles submitted. He was the IEEE MTT-S President in 2011. He is currently a Reviewer for the IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECH-

NIQUES, the IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS—PART I and the IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS—PART II, and EMC publications. He served as the Chair for MTT-8 for seven years and continues with MTT-8/TPC work for many conferences, including the MTT-S IMS, EuMW, the Asia–Pacific Microwave Conference, and others. He is the organizer of the annual IWS conference in China.