Dual-mode Stepped-impedance Resonator Research Articles

Design of dual-mode SIR bandpass filter based on shorting pin for wireless communication applications

<p id="docs-internal-guid-6a9909c3-7fff-4ac4-3e3a-a2f823e1246f" dir="ltr"><span>A new design of microstrip dual mode band-pass-filter (BPF) by using stepped impedance resonator (SIR) based on shorting pin is proposed. The designed structure use two U-shaped tri-sections SIR resonators coupled to each other and a two coupled line feeding ports each of 50 ohm impedance. Shorting pins are used to excite the upper frequency passband in the re sponse of the filter due to current distribution perturbation at the locations of the shorting pins. For demonstration, WLAN (5.2-5.7 GHz) and GSM (1.85-1.99 GHz) and Advanced Wireless Services (AWS) (1.71-1.755 GHz). The return losses are -32.469 dB and -26.18 dB respectively at the operating frequencies of the filter. The results of insertion losses of the filter is 0.37 and 0.24 dB during the operating bands and more than 25 dB which consider a good out-of- band rejection. </span></p>

Compact superconducting single- and dual-band filter design using multimode stepped-impedance resonator**Project supported by the National Natural Science Foundation of China (Grant No. 61371009) and the Fund from the Chinese Ministry of Science and Technology (Grant No. 2014AA032703).

This study presents two multimode stepped-impedance structures to design single- and dual-band filters. Transmission zeroes are introduced for the single-band filter by using dual-mode stepped-impedance resonators. The single-band filter with high selectivity is centered at 6.02 GHz and has a fractional bandwidth (FBW) of 25.6%. Four stubs (two low frequency and two high frequency ones) are connected to the rectangular patch in the center to construct a quadruplemode resonator. The independent conditions of the center frequencies of the high and low bands of the resonator are analyzed. A dual-band filter, which operates at 1.53 GHz and 2.44 GHz with FWBs of 12.1% and 14.1%, respectively is designed. The single- and dual-band filters are both fabricated with double-sided YBCO films and they can be used in mobile and satellite communications.

Novel LTCC Distributed-Element Wideband Bandpass Filter Based on the Dual-Mode Stepped-Impedance Resonator

In this paper, a novel compact 3-D dual-mode stepped-impedance resonator (SIR) with centrally loaded stub is constructed for designing a wideband low-temperature cofired ceramic (LTCC) bandpass filter (BPF). By fully taking advantage of the LTCC technology, the dual-mode SIR, as a cell unit of the proposed filter, is reasonably folded in 3-D environment, and its properties are investigated using the transmission line theory. Accordingly, benefiting from the 3-D circuit layout, the proposed BPF designed by combining the SIR and dual-mode techniques can effectively overcome a vital and common drawback of large circuit size of the LTCC distributed-element filters. For demonstration, a fourth-order wideband BPF centered at 5 GHz is designed, fabricated, and measured. The circuit size of the designed BPF has a compact size of 3.875 × 4.8 × 1.4 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> . The impact of the package on the coupling and routing scheme and frequency response/transmission zero has been analyzed and demonstrated. The simulated and measured results are presented and compared, showing a good agreement.

UWB BPF with triple notched bands using novel dual-mode SIR and asymmetrical coupling structure

A novel ultra-wideband (UWB) bandpass filter (BPF) with triple notched bands is presented in this paper. The basic UWB BPF is realized by a Y-shaped multi-mode resonator. In order to reject the interfered signals, a novel dual-mode stepped impedance resonator is embedded to introduce dual notched bands at 5.85/8.13 GHz. Due to the asymmetrical coupling structure, another notched band centered at 7.12 GHz is implemented as well. Analysis of the filter has been done with classical even- and odd-mode methods. For verification, two sample filters have been simulated, fabricated, and measured. Good agreement is found between the simulations and measurements. The implementation area of the proposed filter is 14.7 × 10.1 mm2.

Compact dual-mode dual-band bandpass filter with wide stopband

A compact microstrip bandpass filter (BPF) with dual-band and wide stopband based on a single dual-mode stepped-impedance resonator (SIR) and defected ground structures (DGSs) is investigated in this paper. The proposed BPF is composed of one dual-mode resonator with metalized via hole to ground, one spiral slot and three DGSs. The dual-mode SIR is studied and employed to generate two desired independent passbands. The DGSs are used to improve the stopband performance. The predicted results are compared with measured data, and a good agreement is reported.

Dual-band BPF with DSIR and TSIR

A novel dual-band microwave bandpass filter (BPF) is proposed using a dual-mode stepped impedance resonator (DSIR) and a three-mode stepped impedance resonator (TSIR). Either of the SIRs can not only separately generate one passband but also control the passband performance. Owing to the intrinsic characteristics of the SIRs, each passband has a pair of transmission zeros to improve the selectivity. A dual-band filter located at 1.57 GHz (GPS application) and 2.4 GHz (WLAN application) is designed and fabricated. Good agreements are obtained between measured and simulated S-parameters.