Filter Parameter Extraction for Triple-Band Composite Split-Ring Resonators and Filters

A controllable compact dual-band bandpass filter using loaded open-loop resonators

“…There are six rings in this design which are a pair of R 1 , R 2 and R 3 . This coupling structure can be modeled by the full coupling model [15]. The coupling schematic has been shown in Fig.…”

“…In this schematic, the solid lines represent the major coupling and the dash lines represent the cross coupling. The cross couplings between the inner resonators and source or load are very small [15]. As the topology shown in Fig.…”

“…2, R 1 is the major coupling path for f 1 and f 2 from the input to output and R 2 is used as a coupling ring. With this structure, the end coupling and multi-path of R 1 , R 2 and R 3 help generate the TZs for the proposed filter [14,15]. Since the gaps, n and m as shown in Fig.…”

“…Since the gaps, n and m as shown in Fig. 1, also play an important role in the coupling coefficients, bandwidth and TZs positions [14,15], there is a compromise between them to realize the filter specifications. To verify the coupling structure, the electromagnetic simulator has been used to simulate the proposed filter and to illustrate the specific stubs and gaps performance on the proposed filter.…”

Design of a compact triple-band bandpass filter using triple-mode stub-loaded step-impedance resonator

“…Recently, increasing numbers of tri-band filters have been utilized, with three typical methods used to realize the triple-band property. The first method is to introduce transmission zeros inside the passband of the BPFs to split a single passband to three passbands [3,4]. The transmission zeros can be generated via cross coupling.…”