“…The fundamental frequencies of resonator 1 and 2, resonator 3 and 4, resonator 5 and 6, and resonator 7 and 8 are located at 3, 5, 7 and 9 GHz, respectively, where frequencies of the higher order resonant modes of each coupled resonator are higher than the four passband frequencies by controlling the parameters of SIR. The parameters of the BPF are summarized in Table I FBW M g g (4) where g are the element values of the lowpass prototype filter, and FBW is the fractional bandwidth. The coupling coefficients are then used to determine the gap D 12 (D 34 , D 56 , D 78 ) between the resonators.…”