“…By superpositioning out-of-phase RF signals from two in-parallel cascaded signal paths, a theoretically infinite rejection can be achieved in the output of these filters. Alternative ABSF topologies have been proposed to date using microstrip transmission line-based resonators [4], [5], [6], [7], [8], acoustic wave resonators [9], lumped element (LE) components [10], substrate integrated coaxial (SIC) cavities [11], [12], multilayer CPW configurations [13], and thin-film integrated devices [14]. The use of transmission line and CPW-based configurations results in large circuit volumes due to using large resonators (λ 0 /2 at the design frequency).…”