Fig 1.
Design flow chart.
Fig 2.
Evolution of multimode resonators.
(a) Conventional T-shaped. (b) Half-wavelength shape. (c) Triangular structur. (d) Stepped triangle.
Fig 3.
Stepped triangle resonator structure.
Fig 4.
The odd and even mode structure of Stepped triangle resonator structure.
(a) Odd-mode equivalent structures. (b) Even-mode equivalent structures.
Fig 5.
The influence of coupling line L1 on passband performance.
Fig 6.
Curves of four MMRs under weak coupling.
Fig 7.
Schematic structure of ultra-wideband filter.
Fig 8.
S-parameter simulation results of ultra-broadband filter.
Table 1.
Structural parameters of UWB BPF (mm).
Fig 9.
UWB filter structure with double-notch bands.
Fig 10.
Effect of L13 on notch frequency.
Fig 11.
Surface current distribution diagram.
(a) the center frequency is 6.80GHz. (b) the center frequency is 9.82GHz.
Fig 12.
Effect of R1 on notch frequency.
Fig 13.
Dual-notch UWB filter with highly selective out-of-band rejection.
Fig 14.
Equivalent circuit structure.
Fig 15.
Effect of variation of B1 length on right transmission zero frequency.
Fig 16.
Comparison of structures with and without DGS.
Fig 17.
S-parameter simulation plot diagram.
Fig 18.
Group delay characteristic curve.
Table 2.
Dimensional sizes of the two notch structures and the DGS SSR structure (mm).
Fig 19.
Comparison between test results and simulation results.
Table 3.
Comparison of filter parameters between this work and other filters.