A New Class of Doublet Based on Slotted Slant Ridge in Additive Manufacturing Technology

Additive Manufacturing (AM) technology is becoming very popular for the manufacturing of electromagnetic components. In this paper the flexibility of the AM is exploited to obtain compact waveguide filters. Filters are based on transverse slant ridge resonators inside a rectangular waveguide. The ridge incorporates a slot, possibly folded. The resonance of the slot is exploited in addition to the resonance of the transverse slanted ridge to obtain a compact dual mode resonator. Therefore, a single slotted ridge can produce two poles and two transmission zeros (TZs). Control of couplings to ridge resonance is obtained by using the slant angle, while control of couplings to slot resonance is obtained by folding the slot in different points. The structure realizes a transversal topology allowing the control of the transmission zero by controlling the ratio between coupling to ridge resonance and coupling to slot resonance.