Fig 1.
Physical structure of the proposed resonator with its approximated LC circuit, where the equivalents of la, lb, lc, ld, coupling and open-end capacitors are La, Lb, LC, Ld, C and CO respectively.
Fig 2.
Simplifying the LC circuit (using Δ-Y transformation).
Fig 3.
The proposed BPFs with their frequency responses, where all dimensions are written in mm.
Fig 4.
The proposed triplexer composed of BPF1, BPF2 and BPF3 (unit: mm).
Fig 5.
Current density distributions of the designed triplexer for simulating ports 2, 3 and 4 at 2.5 GHz, 4.4 GHz and 6 GHz, respectively.
Fig 6.
Frequency responses as nine functions of the effective physical dimensions l1, l2, l3, l4, S1, S2, w1, w2, w3.
Fig 7.
Common port return loss and isolations as six functions of the effective physical dimensions l1, l2, l3, l4, S1 and S2.
Fig 8.
Simulated (solid lines) and measured (dashed lines) frequency responses of the proposed triplexer.
Fig 9.
Narrowband and wideband group delays at all channels.
Fig 10.
Fabricated triplexer.
Table 1.
Comparison between our triplexer and the previous works (*: Approximated values).
Table 2.
Group delay comparison (*: Approximated values).