Cross Coupling in Folded Interdigital Filters using Quarter-Wavelength Resonators with Non-Planar Structures

This work presents cross coupling in non-planar interdigital filters using shorted quarter-wave resonators. The filter structure is folded about one axis to bring non-adjacent resonators closer to each other and introduce cross coupling. The filter is fabricated in the PolyStrata
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technology where additive manufacturing process allows for high volume production, repeatable, and low cost filters which scales to sub-THz frequencies. As an example, we present a compact E-band diplexer with wire-bondable ground-signal-ground (GSG) interface