SLM Printed Waveguide Dual-Mode Filters With Reduced Sensitivity to Fabrication Imperfections

Abstract

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Vertically Printable Evanescent Mode Filters

“…The manufacturing feasibility of the presented proposal is here illustrated by means of two identical breadboards associated with the same design, printed by means of Selective Laser Melting (SLM). One of the main reasons to choose SLM over other AM techniques is that it can be used directly for spaceborne and other harsh environment applications since it is the only AM technique that allows the use of metallic powder as building material [1], [4], [5], [7].…”

“…The state-of-the-art review shows that, in order to attain both high precision and high symmetry, the piece should be oriented in such a way that the main waveguide (WG) propagation axis is aligned with the building direction (the vertical axis) [1]. The WG devices that satisfy such condition can be regarded as vertically printable, and they must be carefully designed so that the internal surfaces [4], tilted irises [6], [8], or spherical resonators [7]. It should be noted that it is possible to 3-D-print monolithic components that are not vertically printable [11], [12].…”

SLA printed horn antenna with filtering network based on dual‐mode ellipsoid resonator

“…The perturbated ellipsoid resonator is a special design that not only prevent sharp corners (good for the printing process) but also reduce the sensitivity of the filter performance against the fabrication imperfections. 9 Figure 3 shows the resonant modes and the electric field distribution inside the resonators. As the ellipsoid resonator is only slightly modified from a spherical resonator, so the fundamental mode is TM 101 .…”

“…It is shown in our previous work that, using dimple structure, the sensitivity of both frequency and coupling coefficient tuning can be obviously reduced, so the device can be easily fabricated without the need of post tuning. 9 Furthermore, coupling between resonators are introduced by cylindroid connections rather than rectangular irises to reduce the discontinuities. It is worth noting that the horizontal window (labeled as w 1 in Figure 2) between resonator 1 and 2 provides a cross coupling between mode 1 and mode 4, generating a pair of transmission zeros near the passband.…”

Monolithic Multiband Coaxial Resonator-Based Bandpass Filter Using Stereolithography Apparatus (SLA) Manufacturing

“…Although metal-based AM, such as direct metal laser sintering (DMLS) [31], selective laser sintering (SLM) [32]- [36], binder jetting [37], and electron beam melting (EBM) [38], exhibits high mechanical robustness and is potentially suitable for monolithic integration, they suffer from high surface roughness, which results in high IL This work is licensed under a Creative Commons Attribution 4.0 License. For more information, see https://creativecommons.org/licenses/by/4.0/ for high-frequency RF components [39], [40]. Plastic/resinbased AM process, such as stereolithography apparatus (SLA), provides lower surface roughness.…”