Fig 1 . Topology schematic of the duplexer with resonating
frequencies, coupling coefficients and the external Q. (Black solid
circle represent the resonators. Numbers next to the lines connecting
the circles represent coupling coefficients or external Q . Solid
line segments with arrows: FDC the pair \(\frac{k_{0i,j}}{C_{i,j}}\).)
The diplexer simulation model is shown in Fig. 2, whose dimensions are
55mm×21mm×19mm, the simulation response and synthesis response are
matched well as shown in Fig. 3.