3-D printed filter based on helical resonators with variable width

This paper presents a helical resonator bandpass filter produced using a stereolighography (SLA) based 3-D printing technique. The filter is formed of four coupled helical resonators, and for each resonator the helix is fixed at both ends so that the resonator is less prone to vibration. The helix is designed to have variable width and this yields enhanced performance in terms of a higher unloaded quality factor and a spurious resonance at higher frequencies. Such a helix is ideally suited to 3-D printing which allows easy production of complex structures. The whole filter is printed from a resin, then plated with metal, and tested. The measured result has a good agreement with simulations.

[1]  Anatol I. Zverev,et al.  Handbook of Filter Synthesis , 1967 .

[2]  N. P. Spencer,et al.  A review of the design of helical resonator filters , 1987 .

[3]  Jeremy Everard,et al.  High-Q helical resonator for oscillators and filters in mobile communications systems , 1989 .

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

[5]  Ming Yu,et al.  High performance helical resonator filters , 2004, 34th European Microwave Conference, 2004..

[6]  Ming Yu,et al.  Power-handling capability for RF filters , 2007, IEEE Microwave Magazine.

[7]  Dimitrios Peroulis,et al.  Tunable VHF Miniaturized Helical Filters , 2014, IEEE Transactions on Microwave Theory and Techniques.

[8]  Nick M. Ridler,et al.  3-D Printed Metal-Pipe Rectangular Waveguides , 2015, IEEE Transactions on Components, Packaging and Manufacturing Technology.

[9]  Jeremy Everard,et al.  Dual-band bandpass filter using helical resonators , 2016, 2016 46th European Microwave Conference (EuMC).

[10]  Ping Zhao,et al.  A compact wideband UHF helical resonator diplexer , 2016, 2016 IEEE MTT-S International Microwave Symposium (IMS).

[11]  Cheng Guo,et al.  $W$ -Band Waveguide Filters Fabricated by Laser Micromachining and 3-D Printing , 2016, IEEE Transactions on Microwave Theory and Techniques.

[12]  Marco Guglielmi,et al.  Helical resonator with modulated radius for improved multipactor threshold: Numerical and experimental results , 2016, 2016 46th European Microwave Conference (EuMC).