Monolithic Millimeter-Wave Air-Filled Waveguide Resonator for Filter Applications

Microfabrication of monolithic wafer-level miniaturized millimeter-wave air-filled half-mode waveguide filter based on the inward curving split ring resonator array

“…It has a negligible effect on the performance of the filter for two reasons: on the one hand, the side length of the aperture is much less than the minimum operating wavelength of the filter; on the other hand, the intensity of the electric field is quite small at the position of the square apertures. The CPWto-HMWG transitions are designed at both ends of HMWG filter based on [9,10]. In each transition, there is a copper step with a rectangular copper patch to connect the top layer and gold ground.…”

“…It shows that the transitions and sidewalls are not vertical. This is due to the effect of photoresist reflow of the sacrificial layer during the subsequent baking of the mold layer [10]. The non-vertical profile of the sidewall in the fabricated profile causes the effective HMWG width to be smaller than the initial unrevised simulation model with vertical profiles.…”

“…In addition to waveguide interconnects, mm-wave electronic communication systems demand many other passive components such as filters. The authors recently proposed a reduced-height air-filled 3D waveguide filter at W-band in [10]. A thick film microfabrication process was used, exploiting an inductively coupled half-wavelength waveguide cavity.…”