High Selectivity Dual-Band Bandpass Filter with Tunable Lower Passband

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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Multilayer SIW Dual-Band Filters with Independent Band Characteristics and High Selectivity

Frequenz ◽

10.1515/freq-2019-0024 ◽

2019 ◽

Vol 73 (9-10) ◽

pp. 293-300

Author(s):

Dinghong Jia ◽

Jianqin Deng ◽

Yangping Zhao ◽

Ke Wu

Keyword(s):

High Selectivity ◽

Bandpass Filter ◽

Large Range ◽

Metal Layer ◽

Dual Band ◽

Effective Dimension ◽

Dual Mode ◽

Transmission Zeros ◽

Design Freedom ◽

Good Agreement

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.

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

Journal of Electrical Engineering ◽

10.2478/jee-2020-0060 ◽

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.

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Diplexer Circuit Analysis and Design

Practical Approach to Substrate Integrated Waveguide (SIW) Diplexer - Advances in Mechatronics and Mechanical Engineering ◽

10.4018/978-1-7998-2084-0.ch004 ◽

2020 ◽

pp. 109-121

Keyword(s):

Bandpass Filter ◽

Bandpass Filters ◽

Circuit Model ◽

Circuit Analysis ◽

Dual Band ◽

Model Coupling ◽

Analysis And Design ◽

Circuit Simulator ◽

Novel Method

In this chapter, a novel method of designing a microwave diplexer circuit is presented. This technique involves merging a section of a dual-band bandpass filter (DBF) with a section of two separately designed bandpass filters (BPFs). The chapter covers the step-by-step procedures that informed the successful realization of the diplexer circuit model. The circuit model coupling arrangement, simulation, and results are also covered. The diplexer circuit developed here has been simulated using the Keysight ADS circuit simulator. The results presented show a very good isolation between the transmit and the receive bands of the diplexer circuit.

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A Compact Wideband SIW Bandpass Filter with Wide Stopband and High Selectivity

Electronics ◽

10.3390/electronics8040440 ◽

2019 ◽

Vol 8 (4) ◽

pp. 440 ◽

Cited By ~ 4

Author(s):

Huang ◽

Yuan

Keyword(s):

High Selectivity ◽

Bandpass Filter ◽

Cutoff Frequency ◽

Ring Resonators ◽

Fractional Bandwidth ◽

Split Ring ◽

Electromagnetic Band Gap ◽

Compact Size ◽

Novel Method ◽

Good Agreement

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.

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A Simple Compact Microstrip Wideband Bandpass Filter

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.760-762.236 ◽

2013 ◽

Vol 760-762 ◽

pp. 236-240

Author(s):

Jian Kang Xiao ◽

Wu Zhu ◽

Yong Li ◽

Wei Zhao

Keyword(s):

Bandpass Filter ◽

Bandpass Filters ◽

Size Reduction ◽

Transmission Zeros ◽

Good Agreement

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.

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Dual-Band Bandpass Filter With Controllable Stopband Bandwidth

Frontiers in Physics ◽

10.3389/fphy.2021.809752 ◽

2022 ◽

Vol 9 ◽

Author(s):

Nan Wang ◽

Haokun Wei ◽

Kun Gao ◽

Xiting Ruan ◽

Xiaojian Chen ◽

...

Keyword(s):

Equivalent Circuit ◽

Bandpass Filter ◽

Dual Band ◽

Lowpass Filter ◽

Microstrip Filter ◽

Design Specifications ◽

Transmission Zeros ◽

Good Agreement

A novel dual-band bandpass filter (BPF) is proposed with independently controllable transmission zeros (TZs) which can realize widely tunable stopband bandwidth (BW). The planar microstrip filter consists of a three-degree L-C ladder lowpass filter loaded with two unsymmetrical shorted stubs which are used to produce different TZs. By tuning the parameters of the two unsymmetrical shorted stubs, the TZs can be independently controlled. Therefore, the BPF has independent controllable center frequencies (CFs), passband bandwidths, and stopband bandwidths between adjacent passbands. All the L-C values in the equivalent circuit of the proposed filter are optimized to fulfill the design specifications. For demonstration, a dual-band BPF is designed. The measured results show good agreement with the simulated ones.

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High‐selectivity dual‐mode dual‐band microstrip bandpass filter with multi‐transmission zeros

Electronics Letters ◽

10.1049/el.2016.4103 ◽

2017 ◽

Vol 53 (7) ◽

pp. 482-484 ◽

Cited By ~ 10

Author(s):

Wangshuxing Ieu ◽

Dewei Zhang ◽

Dongfang Zhou

Keyword(s):

High Selectivity ◽

Bandpass Filter ◽

Dual Band ◽

Dual Mode ◽

Transmission Zeros

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Multitransmission Zero Dual-Band Bandpass Filter Using Nonresonating Node for 5G Millimetre-Wave Application

Active and Passive Electronic Components ◽

10.1155/2018/7628598 ◽

2018 ◽

Vol 2018 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Liyun Shi ◽

Jianjun Gao

Keyword(s):

Bandpass Filter ◽

Open Loop ◽

Dual Band ◽

Dual Mode ◽

Millimetre Wave ◽

Transmission Zeros ◽

Coupling Path ◽

Good Agreement

A planer millimetre-wave dual-band bandpass filter with multitransmission zeros is proposed for 5G application. This filter includes two dual-mode open-loop resonators. The U-shape nonresonating node is employed to generate an extra coupling path. Finally, a dual-band bandpass filter with five transmission zeros is obtained. The filter is fabricated and measured. Good agreement between simulation and measurement is obtained.

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

International Journal of Microwave and Wireless Technologies ◽

10.1017/s1759078715001786 ◽

2016 ◽

Vol 9 (2) ◽

pp. 269-274 ◽

Cited By ~ 7

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.

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