scholarly journals A Compact Quint-Band Bandpass Filter Based on Stub-Loaded Resonators

2017 ◽  
Vol 7 (3) ◽  
pp. 1694-1698
Author(s):  
M. Farhat ◽  
J. Munisami ◽  
M. Abdul-Niby ◽  
M. Nahas
Keyword(s):  
Design Methodology ◽  
High Selectivity ◽  
Bandpass Filter ◽  
Center Frequency ◽  
High Isolation ◽  
The Third ◽  
Transmission Zeros ◽  
Band Filter ◽  
Sufficient Degree ◽  
Simulation Results

This paper presents a planar quant-band bandpass filter with a high out-of-band rejection. The filter is based on inter-coupled stub-loaded resonators, where pairs of resonators are electromagnetically coupled to each other and the feed lines. This results in excitation of passbands, where the first and the third passbands are generated by λ/4 stub-loaded resonators. The second and the fifth passbands are excited by λ/2 stub-loaded resonators. And the fourth passband is generated by λ/2 resonators. The proposed technique provides sufficient degree of freedom to control the center frequency and bandwidth of the five passbands. In addition, the seven transmission zeros created around the passbands results in a quant-band filter with high selectivity, sharp 3dB cut-off frequency, high isolation, and low passband insertion-loss. Design methodology and simulation results of the filter are provided.

scholarly journals A Dual-Mode Bandpass Filter with Multiple Controllable Transmission-Zeros Using T-Shaped Stub-Loaded Resonators

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Zh. Yao ◽  
C. Wang ◽  
N. Y. Kim
Keyword(s):  
High Selectivity ◽  
Bandpass Filter ◽  
Second Harmonic ◽  
Center Frequency ◽  
Harmonic Frequency ◽  
Dual Mode ◽  
Mode Theory ◽  
Transmission Zeros ◽  
Coupling Capacitance ◽  
Compact Size

A dual-mode broadband bandpass filter (BPF) with multiple controllable transmission-zeros using T-shaped stub-loaded resonators (TSSLRs) is presented. Due to the symmetrical plane, the odd-even-mode theory can be adopted to characterize the BPF. The proposed filter consists of a dual-mode TSSLR and two modified feed-lines, which introduce two capacitive and inductive source-load (S-L) couplings. Five controllable transmission zeros (TZs) can be achieved for the high selectivity and the wide stopband because of the tunable amount of coupling capacitance and inductance. The center frequency of the proposed BPF is 5.8 GHz, with a 3 dB fraction bandwidth of 8.9%. The measured insertion and return losses are 1.75 and 28.18 dB, respectively. A compact size and second harmonic frequency suppression can be obtained by the proposed BPF with S-L couplings.

scholarly journals A Compact Tri-Band Bandpass Filter with High Out-of-Band Rejection

2017 ◽  
Vol 7 (4) ◽  
pp. 1786-1790
Author(s):  
M. Abdul-Niby ◽  
M. Farhat ◽  
M. Nahas ◽  
Μ. Μ. Alomari
Keyword(s):  
Degrees Of Freedom ◽  
Bandpass Filter ◽  
Wide Band ◽  
Open Loop ◽  
Dual Band ◽  
Center Frequency ◽  
Transmission Zeros ◽  
Harmonic Rejection ◽  
Band Filter ◽  
Loop Ring

This paper presents a planar tri-band bandpass filter with high out-of-band rejection over a wide band. The filter is based on two pairs of λ/4 resonators embedded inside an open loop ring resonator without any size increase, where each pair of resonators are electromagnetically coupled to each other and the feedlines. This results in the excitations of passbands, where the first passband is generated by the open loop resonators. The second and the third passbands are excited by λ/4 resonators. The proposed technique provides sufficient degrees of freedom to control the center frequency and bandwidth of the three passbands independently. In addition, the six transmission zeros created around the passbands results in a tri-band filter with high selectivity, sharp 3 dB cut-off frequency, high isolation, low passband insertion-loss and high out-of-band harmonic rejection across an ultra-broadband frequency range up to 17 GHz. The proposed technique has the ability to switch from triple to dual band by removing one pair of the inner resonators. Design methodology and simulation results of the filter are provided.

Compact dual-band bandpass filter using open stub-loaded stepped impedance resonator with cross-slots

2016 ◽  
Vol 9 (2) ◽  
pp. 269-274 ◽  
Author(s):  
Bukuru Denis ◽  
Kaijun Song ◽  
Fan Zhang
Keyword(s):  
Bandpass Filter ◽  
Design Concept ◽  
Dual Band ◽  
High Isolation ◽  
Transmission Zeros ◽  
Full Wave ◽  
Measurement Results ◽  
Stepped Impedance Resonator ◽  
Simulation Results ◽  
Good Agreement

A compact dual-band bandpass filter using stub-loaded stepped impedance resonator (SLSIR) with cross-slots is presented. The symmetric SLSIR is analyzed using even- and odd-mode techniques. Design equations are derived and they are used to guide the design of the circuits. Two passbands can be easily tuned by cross-slots and open stubs. Transmission zeros among each passbands are created, resulting in high isolation and frequency selectivity. An experimental circuit is fabricated and evaluated to validate the design concept. The fabricated filter is compact with 19.76 × 12.7 mm2. The measurement results are in good agreement with the full-wave simulation results.

Design of Novel Compact Quad-Band Bandpass Filter with High Selectivity

Frequenz ◽  
2020 ◽  
Vol 74 (1-2) ◽  
pp. 53-59
Author(s):  
Qingchun Cao ◽  
Hui Liu ◽  
Li Gao
Keyword(s):  
Return Loss ◽  
High Selectivity ◽  
Bandpass Filter ◽  
Center Frequency ◽  
Transmission Zeros ◽  
Compact Size ◽  
Left And Right ◽  
Embedded Structure ◽  
Better Than ◽  
Good Agreement

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.

Ultra-compact quasi-elliptic bandpass filter based on capacitive-loaded eighth-mode SIW cavities

2019 ◽  
Vol 12 (2) ◽  
pp. 109-115 ◽  
Author(s):  
Qing Liu ◽  
Dongfang Zhou ◽  
Dewei Zhang ◽  
Chenge Bian ◽  
Yi Zhang
Keyword(s):  
Fourth Order ◽  
High Selectivity ◽  
Bandpass Filter ◽  
Metal Layer ◽  
Center Frequency ◽  
Fractional Bandwidth ◽  
Dielectric Substrates ◽  
Transmission Zeros ◽  
Compact Size ◽  
Metal Layers

AbstractThis paper reports a novel fourth-order quasi-elliptic bandpass filter (BPF) based on capacitive-loaded eighth-mode substrate integrated waveguide (CLEMSIW) cavities. The CLEMSIW cavity is constructed by the conventional eighth-mode SIW with two dielectric substrates and three metal layers; a metal via is employed to connect the middle and bottom metal layers. The middle metal layer achieves a large loading capacitance to shift the resonance frequency. The proposed filter is designed in a quadruple scheme, and two controllable finite-transmission zeros can be realized. For the demonstration, a prototype with a center frequency of 1 GHz and a fractional bandwidth of 10% was designed, fabricated, and measured. The measured results agree well with simulated ones. The proposed filter has advantages of ultra-compact size, high selectivity, and good stopband performances.

Tri-band filter with multiple transmission zeros and controllable bandwidths

2014 ◽  
Vol 8 (1) ◽  
pp. 9-13 ◽  
Author(s):  
Qun Li ◽  
Yong-Hong Zhang ◽  
Xin Feng ◽  
Yong Fan
Keyword(s):  
High Selectivity ◽  
Bandpass Filter ◽  
Electrical Coupling ◽  
Resonant Frequencies ◽  
Splitting Technique ◽  
Transmission Zeros ◽  
Band Filter ◽  
Feed Network ◽  
Multiple Transmission ◽  
Good Agreement

This paper presents a compact microstrip tri-band bandpass filter (BPF) using two multimode stepped-impedance resonators (SIRs) with a 0° feed structure. The fundamental odd-mode and even-mode resonant frequencies and the third resonant frequency are utilized to determine the center frequencies of the tri-band filter. The mode-splitting technique is used by combining two SIRs with electrical coupling. Therefore, two modes generate one passband and the bandwidths can be controlled by the electrical coupling strength. The 0° feed network is applied to create one pair of transmission zeros at each side of all the triple passbands, resulting in high selectivity. Finally, a tri-band BPF with the central frequencies of 1.8, 2.4, and 5.8 GHz, and respective fractional bandwidths of 8.9, 12.5, and 5.3% are designed and fabricated. The simulated and measured results show a good agreement.

Compact dual-mode microstrip bandpass filter based on slotted square patch resonator

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Karthie S. ◽  
Zuvairiya Parveen J. ◽  
Yogeshwari D. ◽  
Venkadeshwari E.
Keyword(s):  
Bandpass Filter ◽  
Filter Design ◽  
Center Frequency ◽  
Dual Mode ◽  
Content Type ◽  
Transmission Zeros ◽  
Compact Size ◽  
Mode Response ◽  
Better Than ◽  
Good Agreement

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.

Miniaturized Wideband Bandpass Filter based on Capacitor-loaded One-eighth Wavelength Coupled Line

2021 ◽  
Vol 36 (7) ◽  
pp. 865-871
Author(s):  
Jin Shi ◽  
Jiancheng Dong ◽  
Kai Xu ◽  
Lingyan Zhang
Keyword(s):  
Insertion Loss ◽  
Simple Structure ◽  
Bandpass Filter ◽  
State Of The Art ◽  
Center Frequency ◽  
Fractional Bandwidth ◽  
Coupled Line ◽  
Transmission Zeros ◽  
Compact Size ◽  
Multiple Transmission

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.

Dual-mode resonator filter with improved feed-lines for dual-band applications

2020 ◽  
Vol 71 (6) ◽  
pp. 433-435
Author(s):  
Shan Shan Gao ◽  
Jia-Lin Li ◽  
Zhe Lin Zhu ◽  
Jia Li Xu ◽  
Yong Xin Zhao
Keyword(s):  
Simple Structure ◽  
High Selectivity ◽  
Bandpass Filter ◽  
Dual Band ◽  
Dual Mode ◽  
Transmission Zeros ◽  
Good Consistency ◽  
Mode Resonator

AbstractAn improved feedline configuration for dual-mode resonator filter is investigated in this paper. Based on the introduced topology, a dual-mode dual-band bandpass filter with center frequencies of 1.8 and 2.4 GHz is optimally designed, fabricated and tested. The introduced dual-band bandpass filter has simple structure and enables high selectivity to be realized due to two pairs of transmission zeros located near to the lower and upper passband, respectively. Both measured and simulated performances are presented with good consistency.

scholarly journals A New Ultracompact Narrow Bandpass Microstrip Filter Using Double-Negative Quasiplanar Cells

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Mohammad Reza Khawary ◽  
Vahid Nayyeri ◽  
Seyed Mohammad Hashemi ◽  
Mohammad Soleimani
Keyword(s):  
Printed Circuit Board ◽  
High Selectivity ◽  
Bandpass Filter ◽  
Circuit Board ◽  
Center Frequency ◽  
Double Negative ◽  
Fractional Bandwidth ◽  
Printed Circuit ◽  
Full Wave ◽  
Good Agreement

This paper presents a novel ultracompact narrow bandpass filter with high selectivity. The proposed filter is composed of cascading two basic cells. Each cell is basically a microstrip line loaded with a quasiplanar resonator and series gaps which can be fabricated using a standard multilayer printed circuit board technology. The structure is analyzed through an equivalent circuit and full-wave simulations. The simulation results are compared with experimental measurements demonstrating a good agreement between them. The measurement indicates that the realized bandpass filter at the center frequency of 1 GHz has a fractional bandwidth of 2.2%. Most importantly, in comparison with other similar recent works, it is shown that the proposed filter has the smallest size.

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