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.

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.

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.

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

Frequenz ◽  
2018 ◽  
Vol 72 (11-12) ◽  
pp. 533-537 ◽  
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.

Miniaturized Dual-Band Bandpass Filter Using Embedded Dual-Mode Resonator with Controllable Bandwidths

Frequenz ◽  
2016 ◽  
Vol 70 (9-10) ◽  
Author(s):  
Chuanming Zhu ◽  
Jin Xu ◽  
Wei Kang ◽  
Zhenxin Hu ◽  
Wen Wu
Keyword(s):  
Insertion Loss ◽  
Degrees Of Freedom ◽  
Bandpass Filter ◽  
The Other ◽  
Dual Band ◽  
Dual Mode ◽  
Transmission Zeros ◽  
Low Insertion Loss ◽  
Multiple Transmission ◽  
Mode Resonator

AbstractIn this paper, a miniaturized dual-band bandpass filter (DB-BPF) using embedded dual-mode resonator (DMR) with controllable bandwidths is proposed. Two passbands are generated by two sets of resonators operating at two different frequencies. One set of resonators is utilized not only as the resonant elements that yield the lower passband, but also as the feeding structures with source-load coupling to excite the other to produce the upper passband. Sufficient degrees of freedom are achieved to control the center frequencies and bandwidths of two passbands. Moreover, multiple transmission zeros (TZs) are created to improve the passband selectivity of the filter. The design of the filter has been demonstrated by the measurement. The filter features not only miniaturized circuit sizes, low insertion loss, independently controllable central frequencies, but also controllable bandwidths and TZs.

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

Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 300 ◽  
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.

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.

A Dual-Band Waveguide Bandpass Filter with Adjustable Transmission Zeros

2018 ◽  
Vol 27 (07) ◽  
pp. 1850100 ◽  
Author(s):  
Amit Bage ◽  
Sushrut Das
Keyword(s):  
Bandpass Filter ◽  
Transverse Plane ◽  
Dual Band ◽  
Center Frequency ◽  
Independent Control ◽  
Transmission Zeros ◽  
Rejection Level ◽  
Multiple Transmission

This paper presents a planar insert-loaded compact, dual-pole, dual-band, waveguide bandpass filter with adjustable multiple transmission zeros. Two identical inserts are placed on the transverse plane of a standard WR-90 waveguide at 8.41[Formula: see text]mm distance to achieve the filter characteristics. The insert consists of a stub-loaded C-shaped resonator and two asymmetric slot resonators. Two stub-loaded C-shaped resonators have been used to achieve dual-pole, dual-band response whereas the asymmetric slot pairs have been used to introduce transmission zeros. The structure allows independent control of the center frequencies of the passbands and transmission zeros, which is useful to control the rejection level of out-of-band signals without disturbing the center frequency. Measured result shows a dual-pole, dual-band, bandpass response with center frequencies at 8.81[Formula: see text]GHz and 10.9[Formula: see text]GHz, the respective 3[Formula: see text]dB bandwidths of 0.276[Formula: see text]GHz and 0.398[Formula: see text]GHz and transmission zeros at 8.02, 8.5, 9.46, 10.13, 11.53 and 12 GHz.

A Novel Dual-Mode Microstrip Bandpass Filter with a Pair of Equal Crossed Slots

2012 ◽  
Vol 236-237 ◽  
pp. 1383-1388
Author(s):  
Su Ping Li ◽  
Cheng Guo Chang ◽  
Wei Wu
Keyword(s):  
Insertion Loss ◽  
Bandpass Filter ◽  
Center Frequency ◽  
Low Loss ◽  
Dual Mode ◽  
Transmission Zeros ◽  
Filter Structure ◽  
Relative Bandwidth

A novel dua1-mode microstrip bandpass filter with two triangle corner cuts and a pair of equal crossed slots is proposed. The performance of the designed filter is studied in detail. The proposed filter structure uses a single patch without coupling gaps. The center frequency is about 2.11GHz. The 3dB relative bandwidth is 9.95%, and the minimum insertion loss in the passband is 0.12dB. Two transmission zeros can be implemented on both sides of the passband. The insertion loss is l0dB within 2.04-2.18GHz. The effect on the filter’s performance by changing filter parameters is studied. The results show that this new filter can provide a low loss and make miniaturization easy.

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