Miniaturized bandpass filter based on double spiral stripline resonators

A new miniature monolithic bandpass filter, which can be manufactured using multilayer standard all-PCB technology, is presented. Each resonator in the filter is formed by metal spirals of the left and right wist inserted into each other, in which one pair of adjacent ends is grounded, and the other is free. Spiral inductors have the form of identical rectangular frames and are designed on dielectric substrates, located on a multilayer structure strictly under each other with alternating turns of the left and right spirals. The design of the filter based on such multilayer double-spiral resonators is both small in size, and highly selective, which is proved by the measured characteristics of the fourth order filter fabricated at seven dielectric layers of RO4350B material. The filter has the central frequency of the passband f0 = 60 MHz, and the fractional bandwidth Δf / f0 = 18%, while the size of the device is of the device are only 34 × 16.5 × 4.3 mm3 (0.007λ0 × 0.003λ0 × 0.001λ0, where λ0 is the wavelength at the center frequency f0). The filter has a wide stopband, which extends up to the frequency of 16f0 at a level of –38 dB.

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

International Journal of Microwave and Wireless Technologies ◽

10.1017/s175907871900120x ◽

2019 ◽

Vol 12 (2) ◽

pp. 109-115 ◽

Cited By ~ 1

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.

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A Wideband Bandpass Filter Integrated Single-Pole Double-Throw Switch with Wide Stopband

Frequenz ◽

10.1515/freq-2018-0045 ◽

2018 ◽

Vol 72 (11-12) ◽

pp. 533-537 ◽

Cited By ~ 1

Author(s):

Jin Xu ◽

Qi-Hang Cai ◽

Zhi-Yu Chen

Keyword(s):

Insertion Loss ◽

Bandpass Filter ◽

Fractional Bandwidth ◽

Central Frequency ◽

Resonant Frequencies ◽

Capacitively Coupled ◽

Filter Theory ◽

Compact Size ◽

Better Than ◽

Coupled Resonator

Abstract This paper proposes a wideband bandpass filter (BPF) integrated single-pole double-throw (SPDT) switch by using the capacitively coupled LC resonators with loaded p-i-n diodes. The BPF-integrated on-state channel can be synthesized by using the coupled resonator filter theory, and the off-state channel with high suppression is built due to the misaligned resonant frequencies of LC resonators. As an example, a BPF-integrated SPDT switch is designed and fabricated with the central frequency of 1 GHz and the 3 dB fractional bandwidth of 29.7 %. The on-state channel has a measured insertion loss of 1.23 dB, and a 20 dB rejection wide stopband from 1.47 GHz to 8.6 GHz. The off state channel has a 43 dB suppression around 1 GHz. The isolation between two ports is better than 52.4 dB. The fabricated BPF-integrated SPDT switch size including bias circuits but excluding feeding lines has a compact size of 0.086 λg×0.096 λg.

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

Applied Computational Electromagnetics Society ◽

10.47037/2021.aces.j.360707 ◽

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.

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

International Journal of Antennas and Propagation ◽

10.1155/2020/5654727 ◽

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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Quadruple-Mode Wideband Bandpass Filter with Improved Out-of-Band Rejection

Electronics ◽

10.3390/electronics8030300 ◽

2019 ◽

Vol 8 (3) ◽

pp. 300 ◽

Cited By ~ 5

Author(s):

Musab Hameed ◽

Gaobiao Xiao ◽

Ali Najam ◽

Lina Qiu ◽

Tayyab Hameed

Keyword(s):

Rectangular Waveguide ◽

Bandpass Filter ◽

Transverse Magnetic ◽

Center Frequency ◽

Fractional Bandwidth ◽

Compact Size ◽

Coaxial Lines ◽

Good Agreement

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.

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Non-Reciprocal Bandpass Filter with Tunable Center Frequency and Constant Fractional Bandwidth

10.1109/imfw49589.2021.9642364 ◽

2021 ◽

Author(s):

Minahil Shirazi ◽

David Chatzichristodoulou ◽

Abdul Quddious ◽

Nosherwan Shoaib ◽

Dimitra Psychogiou ◽

...

Keyword(s):

Bandpass Filter ◽

Center Frequency ◽

Fractional Bandwidth

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A Quasi-Elliptic Bandpass Filter-Integrated Single-Pole Double-Throw Switch

Frequenz ◽

10.1515/freq-2016-0114 ◽

2017 ◽

Vol 71 (5-6) ◽

Cited By ~ 2

Author(s):

Yu-Xue Ji ◽

Jin Xu ◽

Zhao-Zhao Li ◽

Huan Wang ◽

Jin-Jie Huang

Keyword(s):

Insertion Loss ◽

Bandpass Filter ◽

Impedance Matching ◽

Bandpass Filters ◽

Design Approach ◽

Fractional Bandwidth ◽

Central Frequency ◽

Low Insertion Loss ◽

Parallel Configuration

AbstractThis paper proposes a quasi-elliptic bandpass filter-integrated single-pole double-throw (SPDT) switch. The series-parallel configuration of p-i-n diodes embedded into the impedance matching circuit is proposed to combine two quasi-elliptic response bandpass filters to constitute the proposed SPDT switch. To validate our design approach, a proposed quasi-elliptic bandpass filter-integrated SPDT switch is designed and fabricated with a central frequency of 1.25 GHz and a 3 dB fractional bandwidth of 16 %. Low insertion loss in the on state and good isolation in the off state are achieved. The switch size including bias circuits but excluding feeding lines is 0.447λ

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Fabrication of QFN-Packaged Miniaturized GaAs-Based Bandpass Filter with Intertwined Inductors and Dendritic Capacitor

Materials ◽

10.3390/ma13081932 ◽

2020 ◽

Vol 13 (8) ◽

pp. 1932

Author(s):

Jian Chen ◽

Zhi-Ji Wang ◽

Bao-Hua Zhu ◽

Eun-Seong Kim ◽

Nam-Young Kim

Keyword(s):

Gaas Substrate ◽

High Performance ◽

Return Loss ◽

Satellite Communication ◽

Bandpass Filter ◽

Physical Structure ◽

Center Frequency ◽

Fractional Bandwidth ◽

Bridge Structures ◽

Chip Size

This article presents a compact quad flat no-lead (QFN)-packaged second-order bandpass filter (BPF) with intertwined inductors, a dendritic capacitor, and four air-bridge structures, which was fabricated on a gallium arsenide (GaAs) substrate by integrated passive device (IPD) technology. Air-bridge structures were introduced into an approximate octagonal outer metal track to provide a miniaturized chip size of 0.021 × 0.021 λ0 (0.8 × 0.8 mm2) for the BPF. The QFN-packaged GaAs-based bandpass filter was used to protect the device from moisture and achieve good thermal and electrical performances. An equivalent circuit was modeled to analyze the BPF. A description of the manufacturing process is presented to elucidate the physical structure of the IPD-based BPF. Measurements were performed on the proposed single band BPF using a center frequency of 2.21 GHz (return loss of 26.45 dB) and a 3-dB fractional bandwidth (FBW) of 71.94% (insertion loss of 0.38 dB). The transmission zero is located at the 6.38 GHz with a restraint of 30.55 dB. The manufactured IPD-based BPF can play an excellent role in various S-band applications, such as a repeater, satellite communication, and radar, owing to its miniaturized chip size and high performance.

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

Frequenz ◽

10.1515/freq-2019-0043 ◽

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.

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Three-Pole Tunable Bandpass Filters With Constant Fractional Bandwidth Using Mixed Comb-line Resonators

Frequenz ◽

10.1515/freq-2013-0181 ◽

2014 ◽

Vol 68 (9-10) ◽

Author(s):

Zhiyuan Zhao ◽

Jiang Chen ◽

Lin Yang ◽

Kunhe Chen

Keyword(s):

Frequency Band ◽

Bandpass Filter ◽

Bandpass Filters ◽

Center Frequency ◽

Fractional Bandwidth ◽

Tunable Bandpass Filter

AbstractA novel three-pole tunable bandpass filter using mixed combline resonators with a center frequency band of 0.9–1.8 GHz is proposed in this paper. The varactor-tuned filter is designed on a Rogers substrate with

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