A 3-D Printed Lightweight X-Band Waveguide Filter Based on Spherical Resonators

Research output: Contribution to journalArticlepeer-review


External organisations

  • School of Physical Electronics
  • University of Electronic Science and Technology of China
  • University of Birmingham


A fifth order X-band waveguide bandpass filter, based on spherical resonators, has been designed, and fabricated by 3-D printing. In comparison with rectangular waveguide, spherical resonators have a higher unloaded quality factor, but at the same time suffer from closer higher order modes. In this letter, a special topology has been proposed to relieve the impact of the first three higher order modes in the resonator and ultimately to achieve a good out-of-band rejection. Stereolithography based 3-D printing is used to build the filter structure from polymer and a 25 microns thick copper layer is deposited to the filter. The measurement result of the filter has an excellent agreement with the simulations. The filter is also considerably lighter than a similar metal filter.

Bibliographic note

This paper won the 2017 Tatsuo Itoh Prize of the IEEE Microwave Theory and Techniques Society. This award recognizes the most significant contribution by a published paper in the IEEE Microwave and Wireless Components Letters Journal


Original languageEnglish
Article number7115191
Pages (from-to)442-444
Number of pages3
JournalIEEE Microwave and Wireless Components Letters
Issue number7
Early online date1 Jun 2015
Publication statusPublished - 2 Jul 2015


  • 3-D printing, Filter, spherical resonators, stereolithography, waveguide