A high selective tri-band bandpass filter with switchable passband states

2019 ◽  
Vol 12 (2) ◽  
pp. 103-108 ◽  
Author(s):  
Anjan Bandyopadhyay ◽  
Pankaj Sarkar ◽  
Tapas Mondal ◽  
Rowdra Ghatak

AbstractA new class of switchable bandpass filter using PIN diodes is presented in this paper. The design aims at achieving a multistate switchable bandpass filtering characteristics between the passbands centered at 2.4, 3.5, and 5.2 GHz. The proposed filter is designed by assembling two λg/2 open-ended and four short-ended λg/4 uniform impedance resonators. The open-ended resonator generates a fixed passband at 3.5 GHz, whereas the short-ended resonators loaded with PIN diodes are independently controlling the ON and OFF characteristics of the passband centered at 2.4 and 5.2 GHz. The transmission zeros around each passband are produced without employing any additional circuit. The filter sample is fabricated and tested for experimental verification. A good agreement has been observed between EM-simulated and measured results. The designed filter has a compact size of 0.20 λg × 0.15 λg at 2.4 GHz.

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Karthie S. ◽  
Zuvairiya Parveen J. ◽  
Yogeshwari D. ◽  
Venkadeshwari E.

Purpose The purpose of this paper is to present the design of a compact microstrip bandpass filter (BPF) in dual-mode configuration loaded with cross-loop and square ring slots on a square patch resonator for C-band applications. Design/methodology/approach In the proposed design, the dual-mode response for the filter is realized with two transmission zeros (TZs) by the insertion of a perturbation element at the diagonal corner of the square patch resonator with orthogonal feed lines. Such TZs at the edges of the passband result in better selectivity for the proposed BPF. Moreover, the cross-loop and square ring slots are etched on a square patch resonator to obtain a miniaturized BPF. Findings The proposed dual-mode microstrip filter fabricated in RT/duroid 6010 substrate using PCB technology has a measured minimum insertion loss of 1.8 dB and return loss better than 24.5 dB with a fractional bandwidth (FBW) of 6.9%. A compact size of 7.35 × 7.35 mm2 is achieved for the slotted patch resonator-based dual-mode BPF at the center frequency of 4.76 GHz. As compared with the conventional square patch resonator, a size reduction of 61% is achieved with the proposed slotted design. The feasibility of the filter design is confirmed by the good agreement between the measured and simulated responses. The performance of the proposed filter structure is compared with other dual-mode filter works. Originality/value In the proposed work, a compact dual-mode BPF is reported with slotted structures. The conventional square patch resonator is deployed with cross-loop and square ring slots to design a dual-mode filter with a square perturbation element at its diagonal corner. The proposed filter exhibits compact size and favorable performance compared to other dual-mode filter works reported in literature. The aforementioned design of the dual-mode BPF at 4.76 GHz is suitable for applications in the lower part of the C-band.


Frequenz ◽  
2020 ◽  
Vol 74 (1-2) ◽  
pp. 53-59
Author(s):  
Qingchun Cao ◽  
Hui Liu ◽  
Li Gao

AbstractThis paper presents a compact quad-band bandpass filter. The filter is realized by multi-embedded stub-load resonators. By utilizing multi-embedded structure, the whole filter exhibits a compact size. And due to the multi-section stub-loaded lines, four passbands can be realized and the center frequency of the four passbands can be controlled individually to accommodate different communication protocols. Moreover, by using 0° degree feed structure, there are two transmission zeros locates at left and right side of a passband, which greatly enhance the selectivity. To validate the proposed idea, a quad-band bandpass filter, which operates at 2/2.7/3.45/4.55 GHz is implemented. The insertion loss is smaller than 2 dB and return loss is better than 10 dB. Good agreement between the predicted and measured results demonstrates the proposed idea.


2016 ◽  
Vol 9 (5) ◽  
pp. 1029-1035 ◽  
Author(s):  
Jugul Kishor ◽  
Binod K. Kanaujia ◽  
Santanu Dwari ◽  
Ashwani Kumar

Synthesis of differential-mode bandpass filter (BPF) with good common-mode suppression has been described and demonstrated on the basis of ring dielectric resonator (RDR) for high-performance communication system. A RDR with two pairs of feeding lines has been used to excite TE01δ-mode. This unique combination of feeding lines and the ring resonator creates a differential passband. Meanwhile, TM01δ-mode of the DR can also be excited to achieve common-mode rejection in the stopband. Transmission zeros are created in the lower and upper stopband to further improve the selectivity of the proposed BPF. A second-order differential BPF is designed, fabricated and its performance is measured to validate the concept. There is good agreement between simulated and measured results.


Frequenz ◽  
2018 ◽  
Vol 72 (9-10) ◽  
pp. 455-458 ◽  
Author(s):  
Vivek Singh ◽  
Vinay Kumar Killamsetty ◽  
Biswajeet Mukherjee

Abstract In this letter, a miniaturized Band Pass Filter (BPF) with wide stopband centered at 0.350 GHz for TETRA band applications is proposed using a Spiral Short Circuit quarter wavelength Stepped Impedance Resonator (SSC-SIR) and a stub loaded on feed line for enhancement of rejection level in the stopband. Spiral configuration of the resonator is used for the miniaturization of BPF. The proposed BPF provides a 3dB fractional bandwidth of 13.7 % with two transmission zeros in the lower and upper stopband to provide good selectivity and four transmission zeros which provide wide stopband upto 6.86f0. Proposed BPF has a very compact size of 0.064λg×0.062λg.


2021 ◽  
Vol 36 (7) ◽  
pp. 865-871
Author(s):  
Jin Shi ◽  
Jiancheng Dong ◽  
Kai Xu ◽  
Lingyan Zhang

A novel miniaturized wideband bandpass filter (BPF) using capacitor-loaded microstrip coupled line is proposed. The capacitors are loaded in parallel and series to the coupled line, which makes the filter just require one one-eighth wavelength coupled line and achieve filtering response with multiple transmission poles (TPs) and transmission zeros (TZs). Compared with the state-of-the-art microstrip wideband BPFs, the proposed filter has the advantages of compact size and simple structure. A prototype centered at 1.47 GHz with the 3-dB fractional bandwidth of 86.5% is demonstrated, which exhibits the compact size of 0.003λ2 g (λg is the guided wavelength at the center frequency) and the minimum insertion loss of 0.37 dB.


Electronics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 440 ◽  
Author(s):  
Huang ◽  
Yuan

A novel method to design a wideband substrate integrated waveguide (SIW) bandpass filter (BPF) with compact size, wide stopband and high selectivity is presented. In this method some unique electromagnetic band-gap (EBG) cells are periodically etched on the top layer of SIW to realize a wide passband propagating below the equivalent waveguide cutoff frequency. By changing the configuration of EBG cells, undesired harmonics in upper stopband can be suppressed and a wideband BPF with wide stopband can be obtained. By symmetrically loading two complementary split ring resonators (CSRRs) on the tapered gradient lines of the input/output ports, a transmission zero near the passband can be introduced, and it makes the frequency selectivity of upper sideband improve significantly. As a verification, a wideband SIW BPF with a 3.02 GHz absolute bandwidth (ABW) and a 64.7% fractional bandwidth (FBW) centered at 4.67 GHz is designed, simulated, manufactured, and measured. The results of the experiment and simulation are in good agreement.


2013 ◽  
Vol 760-762 ◽  
pp. 236-240
Author(s):  
Jian Kang Xiao ◽  
Wu Zhu ◽  
Yong Li ◽  
Wei Zhao

Two wideband bandpass filters with miniature size and wide stopband are proposed by using cascaded U-shaped resonators. The filters exhibit bandwidths of 31.1% and 28.8% at about 5.3GHz and 5.6GHz, respectively. Both designed filters have simple structures and compact sizes, wide passband, excellent out-band performance with wide lower and upper stopbands, and a pair of transmission zeros on both sides of passband. The new designs have evident circuit size reduction compared with relative reports. A wideband microstrip BPF is fabricated and measured, and the measurement exhibits good agreement with the prediction.


Frequenz ◽  
2019 ◽  
Vol 73 (9-10) ◽  
pp. 293-300
Author(s):  
Dinghong Jia ◽  
Jianqin Deng ◽  
Yangping Zhao ◽  
Ke Wu

Abstract This work presents an approach to developing dual-mode dual-band substrate integrated waveguide (SIW) bandpass filter based on multilayer process. TE102/TE201 and TE101/TE102 modes are used to feature the two passbands, respectively. To begin with, large range of band location ratios are decided by the effective dimension of the SIW resonator. With reference to the field distribution, independent coupling schemes of the dual-modes are then realized by slots or circular apertures etched on the middle metal layer. It allows to not only introduce a large design freedom of bandwidth but also keep compactness. Finally, source-load and mixed couplings are deployed to produce transmission zeros around the passband in providing a sharp selectivity in the two filters, respectively. The details to independently control the center frequencies and bandwidth of two passbands are also presented. A two-order double-layered and a triple-layered SIW dual-band bandpass filter are prototyped to evaluate the proposed design approach, respectively. Results show a good agreement between simulations and measurements. The proposed filter exhibits flexible design freedom, high selectivity as well as good out-of-band rejection.


Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 300 ◽  
Author(s):  
Musab Hameed ◽  
Gaobiao Xiao ◽  
Ali Najam ◽  
Lina Qiu ◽  
Tayyab Hameed

This paper proposes a method for designing a quadruple-mode wideband bandpass filter using off-centered perturbed metallic cylinders in a rectangular waveguide cavity with compact size and improved out-of-band rejection. Two off-centered perturbation cylinders were placed at the bottom of the rectangular waveguide cavity along with a pair of perpendicularly-fed coaxial lines, which excited four quasi-transverse magnetic (TM) modes to realize the desired passband. The height of the waveguide cavity and the shape of the perturbation cylinders were exploited to achieve an all quasi-TM modes filter with good out-of-band rejection and sharp skirt selectivity. The proposed filter operates at 2.93 GHz center frequency with 38% wide fractional bandwidth (FBW). The proposed filter is fabricated using aluminum. The measured and simulated results are in good agreement with each other.


2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Wei-Qiang Pan ◽  
Xiao-Lan Zhao ◽  
Yao Zhang ◽  
Jin-Xu Xu

This paper presents a novel method to design dual-band bandpass filters with tunable lower passband and fixed upper passband. It utilizes a trimode resonator with three controllable resonant modes. Discriminating coupling is used to suppress the unwanted mode to avoid the interference. Varactors are utilized to realize tunable responses. The bandwidth of the two bands can be controlled individually. Transmission zeros are generated near the passband edges, resulting in high selectivity. For demonstration, a tunable bandpass filter is implemented. Good agreement between the prediction and measurement validates the proposed method.


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