Design and Fabrication of PTFE Substrate Integrated Waveguide Coupler by SR Direct Etching

Mitsuyoshi KISHIHARA  Masaya TAKEUCHI  Akinobu YAMAGUCHI  Yuichi UTSUMI  Isao OHTA  

IEICE TRANSACTIONS on Electronics   Vol.E104-C   No.9   pp.446-454
Publication Date: 2021/09/01
Publicized: 2021/03/15
Online ISSN: 1745-1353
DOI: 10.1587/transele.2020ECP5043
Type of Manuscript: PAPER
Category: Microwaves, Millimeter-Waves
microstructure,  X-ray lithography,  dielectric loaded waveguides,  couplers,  millimeter wave circuits,  

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The microfabrication technique based on synchrotron radiation (SR) direct etching process has recently been applied to construct PTFE microstructures. This paper proposes a PTFE substrate integrated waveguide (PTFE SIW). It is expected that the PTFE SIW contributes to the improvement of the structural strength. A rectangular through-hole is introduced taking the advantage of the SR direct etching process. First, a PTFE SIW for the Q-band is designed. Then, a cruciform 3-dB directional coupler consisting of the PTFE SIW is designed and fabricated by the SR direct etching process. The validity of the PTFE SIW coupler is confirmed by measuring the frequency characteristics of the S-parameters. The mechanical strength of the PTFE SIW and the peeling strength of its Au film are also additionally investigated.