scholarly journals An Intrinsically Switched Tunable CABW/CFBW Bandpass Filter

Electronics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1318
Author(s):  
Tiejun Du ◽  
Boran Guan ◽  
Pengquan Zhang ◽  
Yue Gu ◽  
Dujuan Wei
Keyword(s):  
Design Theory ◽  
Bandpass Filter ◽  
Resonant Frequencies ◽  
Rf Switches ◽  
Frequency Space ◽  
Transmission Zero ◽  
Insertion Losses ◽  
Better Than ◽  
Good Agreement ◽  
Tunable Bandpass Filter

In this paper, a novel intrinsically switched tunable bandpass filter based on a dual-mode T-shaped varactor-loaded resonator is presented. The varactors loaded in the T-shaped resonator are capable of efficiently tuning the resonant frequencies of the even and odd modes, as well as the transmission-zero frequency. Without any additional RF switches, the passband of the filter can be intrinsically switched off by adjusting the transmission zero to the resonant frequencies. In the switch-on state, the constant absolute bandwidth (CABW) or constant fractional bandwidth (CFBW) passband can be achieved by controlling the frequency space between the two resonances. For a demonstration, a 0.8–1.1 GHz intrinsically switched tunable bandpass filter with 74 MHz CABW or 8.5% CFBW was fabricated and tested. In the whole operating band with |S11| < 10 dB, the insertion losses for CABW and CFBW are better than 3.3 dB and 3 dB, respectively, and the isolations are better than 20 dB in the switch-off state. The measured results have a good agreement with simulated results, which verifies the design theory.

Compact Diplexer with High Isolation based on Novel Symmetric Double Spiral Resonators

Frequenz ◽  
2016 ◽  
Vol 70 (3-4) ◽  
Author(s):  
Ru Le ◽  
Chi Wensheng ◽  
Liu Yaqing ◽  
Yang Haidong
Keyword(s):  
Bandpass Filter ◽  
High Isolation ◽  
Double Spiral ◽  
Electromagnetic Characteristics ◽  
Insertion Losses ◽  
Better Than ◽  
Good Agreement

AbstractIn this paper, the electromagnetic characteristics of the reported miniaturized bandpass filter (BPF) in reference are investigated deeply, and then a planar compact diplexer centred at 1.86/2.16 GHz is designed by using a T-junction to connect the reported BPFs. For verification, the designed diplexer are fabricated and measured. The measured and simulated results of the diplexer are in good agreement with each other, showing that the measured 3-dB bandwidth for the two passbands are 6.45 % (1.79–1.91 GHz) at 1.86 GHz and 6.94 % (2.08–2.23 GHz) at 2.16 GHz with return losses better than 20 dB. Moreover, the insertion losses of the two passbands are less than 0.7 and 0.9 dB, and the isolations are higher than 48 and 36 dB, respectively. Besides, compared with the diplexers reported in recent references, this one has more superior 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.

scholarly journals High Selectivity Dual-Band Bandpass Filter with Tunable Lower Passband

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Wei-Qiang Pan ◽  
Xiao-Lan Zhao ◽  
Yao Zhang ◽  
Jin-Xu Xu
Keyword(s):  
High Selectivity ◽  
Bandpass Filter ◽  
Bandpass Filters ◽  
Dual Band ◽  
Transmission Zeros ◽  
Resonant Modes ◽  
Novel Method ◽  
Good Agreement ◽  
Tunable Bandpass Filter

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.

scholarly journals A Compact Widely Tunable Bandpass Filter Dedicated to Preselectors

Electronics ◽  
2021 ◽  
Vol 10 (18) ◽  
pp. 2315
Author(s):  
Mirosław Magnuski ◽  
Dariusz Wójcik ◽  
Maciej Surma ◽  
Artur Noga
Keyword(s):  
Tuning Range ◽  
Bandpass Filter ◽  
Cutoff Frequency ◽  
Intermediate Frequency ◽  
Fractional Bandwidth ◽  
Planar Network ◽  
Image Channel ◽  
Double Coupling ◽  
Better Than ◽  
Tunable Bandpass Filter

This article presents a novel compact widely tunable bandpass filter. The filter consists of two resonators that are double-coupled, inductively, where the coupling inductances are elements of the input and output networks. The application of double-coupling enabled the transmission zero next to the upper cutoff frequency. This makes the filter useful for applications in preselector networks used in receiving systems with a low to intermediate frequency with the desired channel frequency lower than the image channel frequency. The article shows the practical realisation of the varactor-tuned example filter fabricated as a microstrip planar network of an overall size of 0.03λg × 0.045λg. The tuning range of the proposed filter is from 410 MHz to 880 MHz with the fractional bandwidth equal to 7.5–8.1% and an in-band insertion loss better than −3.4 dB. The achieved IP3 value exceeds 17.5 dBm.

Generalized Chebyshev Highpass Filter based on Suspended Stripline Structure (SSS) for Wideband Applications

2014 ◽  
Vol 68 (3) ◽  
Author(s):  
Z. Zakaria ◽  
M. A. Mutalib ◽  
M. S. M. Isa ◽  
N. Z. Haron ◽  
A. A. Latiff ◽  
...  
Keyword(s):  
Communication Systems ◽  
Cutoff Frequency ◽  
Lowpass Filter ◽  
Finite Frequency ◽  
Transmission Zero ◽  
Physical Volume ◽  
Highpass Filter ◽  
Filter Prototype ◽  
Better Than ◽  
Good Agreement

This paper presents the method to transform generalized Chebyshev lowpass filter prototype to highpass filter based on Suspended Stripline Structure (SSS) technology. The study involves circuit analysis to determine generalized Chebyshev responses with a transmission zero at finite frequency. The transformation of the highpass filter from the lowpass filter prototype produces a cutoff frequency of 3.1 GHz with a return loss better than -20 dB. The design is simulated and measured on a Roger Duroid RO4350 with a dielectric constant, ɛr of 3.48 and a thickness of 0.508 mm. The experimental results are in good agreement with the simulated results. This class of generalized Chebyshev highpass filter with finite transmission zero would be useful in any RF/ microwave communication systems particularly in wideband applications where the reduction of overall physical volume and weight as well as cost very important, while maintaining its excellent performance.

scholarly journals Harmonic-Rejection Compact Bandpass Filter Using Defected Ground Structure for GPS Application

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Haiwen Liu ◽  
Baoping Ren ◽  
Xiang Xiao ◽  
Zhichong Zhang ◽  
Shen Li ◽  
...  
Keyword(s):  
Design Methodology ◽  
Bandpass Filter ◽  
Second Order ◽  
Defected Ground Structure ◽  
Ground Structure ◽  
Transmission Zeros ◽  
Harmonic Rejection ◽  
Rejection Level ◽  
Better Than ◽  
Good Agreement

A miniaturized bandpass filter (BPF) using defected ground structure (DGS) resonator with the characteristic of harmonic rejection is developed in this paper. The second and third harmonics of the proposed BPF are rejected by the characteristic of stepped-impedance DGS resonator. Moreover, open stubs are established so that two adjustable transmission zeros can independently be created to extend the stopband and improve the rejection level. Finally, a second-order BPF, centered at 1.62 GHz with a stopband extended up to 5.6 GHz and a rejection level better than 20 dB, is designed and implemented for GPS application. A good agreement between simulation and measurement verifies the validity of this design methodology.

Compact Dual-Band Bandpass Filter Using Stubs Loaded Ring Resonator

Frequenz ◽  
2016 ◽  
Vol 70 (1-2) ◽  
Author(s):  
Jin Xu
Keyword(s):  
Bandpass Filter ◽  
Ring Resonator ◽  
Design Guidelines ◽  
Second Order ◽  
Dual Band ◽  
Compact Size ◽  
Mode Method ◽  
Resonant Characteristic ◽  
Better Than ◽  
Good Agreement

AbstractThis paper presents a novel second-order dual-band bandpass filter (BPF) by using proposed stubs loaded ring resonator. The resonant behavior of proposed stubs loaded ring resonator is analyzed by even-/odd-mode method, which shows its multiple-mode resonant characteristic. Parameters sweep is done so as to give the design guidelines. As an example, a second-order dual-band BPF operating at 1.8/5.2 GHz for GSM and WLAN applications is designed, fabricated and measured. The fabricated filter has a very compact size of 0.05λg×0.15λg. Measured results also show that the proposed dual-band BPF has a better than 20 dB rejection upper stopband from 5.47 GHz to 12.56 GHz. Good agreement is shown between the simulated and measured results.

scholarly journals Dual-band bandpass filter based on two U-shaped defected microstrip structure

2021 ◽  
Vol 22 (2) ◽  
pp. 909
Author(s):  
Mussa Mabrok ◽  
Zahriladha Zakaria ◽  
Yully Masrukin ◽  
Tole Sutikno
Keyword(s):  
Bandpass Filter ◽  
Short Circuit ◽  
Notch Filter ◽  
Dual Band ◽  
Design System ◽  
High Attenuation ◽  
Quarter Wavelength ◽  
Insertion Losses ◽  
Microstrip Structure ◽  
Better Than

This paper presents design of dual-band bandpass filter by integrating conventional quarter-wavelength short circuit stubs bandpass filter with U-shaped defected microstrip structure notch filter. Based on the parametric analysis, it is found that high attenuation level can be achieved by using two U-shaped defected microstrip structure separated by specific distance. The designed circuit simulated using advanced design system and fabricated based on Roger 4350B. The simulation results are in good agreement with measured results. The designed filter covered two pass bands centered at 2.51 GHz and 3.59 GHz with 3-dB fractional bandwidth of 15.94% and 15.86%, respectively, return losses better than 15 dB, and insertion losses better than 1 dB. The designed device can be used for wireless communication applications such as WLAN and WiMAX.

scholarly journals Novel Notched UWB Filter Using Stepped Impedance Stub Loaded Microstrip Resonator and Spurlines

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Ramkumar Uikey ◽  
Ramanand Sagar Sangam ◽  
Kakumanu Prasadu ◽  
Rakhesh Singh Kshetrimayum
Keyword(s):  
Bandpass Filter ◽  
Experimental Results ◽  
Microstrip Resonator ◽  
Resonant Frequencies ◽  
Notched Band ◽  
Band Filter ◽  
5 Ghz ◽  
Good Agreement

This paper presents a novel ultrawideband (UWB) bandpass filter using stepped impedance stub loaded microstrip resonator (SISLMR). The proposed resonator is so formed to allow its four resonant frequencies in the UWB passband, which extends from 3.1 GHz to 10.6 GHz. Moreover, two spurline sections are employed to create a sharp notched-band filter for suppressing the signals of 5 GHz WLAN devices. Experimental results of the fabricated filters are in good agreement with the HFSS simulations and validate the design.

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