Photonic band gap higher order mode coupler for the international linear collider

A photonic band gap (PBG) higher-order-mode (HOM) coupler is proposed as an alternative configuration design (ACD) for the HOM coupler for the international linear collider (ILC). The PBG HOM coupler uses a two-dimensional triangular PBG structure with good axial symmetry. Simulation studies of a PBG HOM coupler show that it maintains the operating mode at 1.3 GHz with
Q
> 10
¹⁰
. While a PBG HOM coupler provides superior damping for all the higher order modes, in principle, the effectiveness of HOM damping remains an open subject of future investigations.