Submillimeter‐wave waveguide filters fabricated by SU‐8 process and laser micromachining. Issue 14 (5th October 2017)

• Record Type: Journal Article
• Authors: Shang, Xiaobang; Yang, Hao; Glynn, David; Lancaster, Michael J.
• Is Part Of: IET microwaves, antennas & propagation. Volume 11:Issue 14(2017)
• Page Start: 2027
• Page End: 2034
• Publication Date: 2017-10-05
• Subjects: waveguide filters -- passive filters -- submillimetre wave filters -- micromachining -- laser beam machining -- rectangular waveguides; submillimeter‐wave waveguide filters -- laser micromachining -- terahertz systems -- rectangular waveguide -- low loss medium -- passive circuits -- submillimeter wavelengths -- WR‐3 waveguide -- computer numerical control milling -- CNC milling -- terahertz waveguides -- SU‐8 photoresist process -- quality terahertz passive components -- frequency 220 GHz to 325 GHz; Microwaves -- Periodicals; Microwave antennas -- Periodicals; Antennas (Electronics) -- Periodicals; Radio wave propagation -- Periodicals; Microwave communication systems -- Periodicals; 621.381305
• DOI: 10.1049/iet-map.2016.0951
• Languages: English
• ISSNs: 1751-8725

Abstract

Abstract : For terahertz systems, rectangular waveguide is an ideal low loss medium for interconnectivity and the construction of passive circuits. A drawback when manufacturing waveguides at submillimeter wavelengths is the demanding tolerances due to small dimensions. For example, a WR‐3 waveguide (operating between 220 and 325 GHz) has a cross‐sectional dimension of just 864 by 432 µm, and higher frequency waveguides get proportionally smaller. An additional challenge is that whether using waveguide for passive circuits such as filters, there are additional structures inside the waveguide which are significantly smaller than the waveguide itself. Traditionally, computer numerical control (CNC) milling has been used for waveguides, however at terahertz frequencies this is difficult to utilise. Emerging technologies for terahertz waveguides are compared with conventional CNC solutions. The technologies include the photolithography‐based polymer etching of waveguides using SU‐8 photoresist, and the laser machining of metal. Both have shown promise, and good quality terahertz passive components have been fabricated and measured.