This study presents two multimode stepped-impedance structures to design single-and dual-band filters. Transmission zeroes are introduced for the single-band filter by using dual-mode stepped-impedance resonators. The...This study presents two multimode stepped-impedance structures to design single-and dual-band filters. Transmission zeroes are introduced for the single-band filter by using dual-mode stepped-impedance resonators. The single-band filter with high selectivity is centered at 6.02 GHz and has a fractional bandwidth （FBW） of 25.6%. Four stubs （two low frequency and two high frequency ones） are connected to the rectangular patch in the center to construct a quadruple-mode resonator. The independent conditions of the center frequencies of the high and low bands of the resonator are analyzed. A dual-band filter, which operates at 1.53 GHz and 2.44 GHz with FWBs of 12.1% and 14.1%, respectively is designed. The single-and dual-band filters are both fabricated with double-sided YBCO films and they can be used in mobile and satellite communications.展开更多
A high performance Balun BandPass Filter (BPF) with capacitively loaded multiple coupled lines with very simple structure is proposed in this paper, this structure realizes simultaneous size reduction and superior har...A high performance Balun BandPass Filter (BPF) with capacitively loaded multiple coupled lines with very simple structure is proposed in this paper, this structure realizes simultaneous size reduction and superior harmonic response suppression performance in bandpass filtering meanwhile good differential performance of the Balun. The theory of this structure for unbalanced input into balanced output has been studied in this paper and a proper Balun and BPF characteristic by the symmetric feeding and skew symmetric feeding have been obtained to prove the theory. The enter frequency of the fabricated Balun-BPF is operated at 2.45 GHz with 6.93% Fractional Band Width (FBW), and this frequency is used for Bluetooth and some other communication systems. The differences between the two outputs are 180°± 1.92° in phase and within 0.33 dB in magnitude. At f0, the amplitude imbalance and phase difference are within 0.25 dB and 180.86°, respectively. The measured frequency responses agree well with the simulated ones. With the theoretical analyses and practical results, it is shown that the proposed one has the advantages of simple structure, convenient analysis and good performance of both BPF and Balun.展开更多
In this paper,a Slotted Stepped-Impedance Resonator (SSIR) is proposed.Due to the slots in the low-impedance section of the conventional SIR,the new resonator has a lower fundamental resonance f0 and can provide a pot...In this paper,a Slotted Stepped-Impedance Resonator (SSIR) is proposed.Due to the slots in the low-impedance section of the conventional SIR,the new resonator has a lower fundamental resonance f0 and can provide a potential finite transmission zero fz close to f0.Based on the proposed SSIR,a fourth-order Chebychev BandPass Filter (BPF) is designed at f0=1 GHz.The measured results show that a better than-65 dB rejection is achieved on both the lower and the upper stopband.Moreover,the new filter has a wide-30 dB rejection upper stopband from 1.13f0 to 6.52f0.The fabricated filter exhibits a size of The new filter has a planar topology and is easily integrated with modern portable communication systems.展开更多
A compact input-reflectionless balanced bandpass filter(BPF)with flexible bandwidth(BW)using a three-line coupled structure(TLCS)is presented in this paper.For the differential mode(DM),the TLCS is applied to achieve ...A compact input-reflectionless balanced bandpass filter(BPF)with flexible bandwidth(BW)using a three-line coupled structure(TLCS)is presented in this paper.For the differential mode(DM),the TLCS is applied to achieve the bandpass response;meanwhile,the input coupled-feed line of the TLCS is reused in the input absorption network.This design shows a good fusion of the absorptive and BPF sections,effectively reducing the circuit size,and the BWs of the two sections that can be controlled separately result in a flexibly controllable DM response BW of the proposed input-reflectionless balanced BPF.Detailed analyses of the ratio of the two-part BWs have been given for the first time,which is vital for the passband flatness and reflectionless feature.In the codesign of this work,the input-reflectionless DM bandpass response can be optimized easily,while wideband common mode(CM)noise absorption is achieved by the input absorption network.To verify the design method,a prototype with a compact layout(0.52λ×0.36λ)is designed and measured in the 0-7.0 GHz range.The DM center frequency(f0)is 2.45 GHz with a measured 3 dB fractional bandwidth of 31.4%.The simulation and measurement results with good agreement are presented,showing good performance,e.g.,low insertion loss(0.43 dB),wide upper stopband for the DM bandpass response(over 20 dB rejection level up to 2.72f0),and wideband DM reflectionless and CM noise absorption(fractional absorption bandwidth of 285.7%).展开更多
A liquid-loaded frequency tunable cavity bandpass filter (BPF) is presented. A dielectric fluidic material, dimethyl silicone oil (DSO) withexcellent thermophysical characteristics (working temperature from −50 ℃ to ...A liquid-loaded frequency tunable cavity bandpass filter (BPF) is presented. A dielectric fluidic material, dimethyl silicone oil (DSO) withexcellent thermophysical characteristics (working temperature from −50 ℃ to 180 ℃) and extremely low loss tangent is employed as a dielectric loading.The frequency reconfigurability of the proposed design is realized by altering the liquid level inside the cavity resonator. The filter achieves a widefrequency tuning range as well as a high Q factor. Moreover, this design shows significantly improved environmental suitability in extreme temperaturecases, outperforming the existing microfluidic-based RF devices using water or liquid metals. A four-pole tunable cavity bandpass filter is designed andverified. A cross-coupling structure comprising a metal loop structure is used to introduce transmission zeros in the proposed filter, which enhances theskirt selectivity and out-of-band rejections. We demonstrate that the center frequency of the proposed BPF can be tuned from 4.92 GHz to 6.16 GHz,and the filter achieves a high Q factor between 521 and 1527. The measured results agree well with simulated results.展开更多
Compact dual-band bandpass filter(BPF)for the 5 th generation mobile communication technology(5 G)radio frequency(RF)front-end applications was presented based on multilayer stepped impedance resonators(SIRs).The mult...Compact dual-band bandpass filter(BPF)for the 5 th generation mobile communication technology(5 G)radio frequency(RF)front-end applications was presented based on multilayer stepped impedance resonators(SIRs).The multilayer dual-band SIR BPF can achieve high selectivity and four transmission zeros(TZs)near the passband edges by the quarter-wavelength tri-section SIRs.The multilayer dual-band SIR BPF is fabricated on a 3-layer FR-4 substrate with a compact dimension of 5.5 mm×5.0 mm×1.2 mm.The measured two passbands of the multilayer dual-band SIR BPF are 3.3 GHz-3.5 GHz and 4.8 GHz-5.0 GHz with insertion loss(IL)less than 2 dB respectively.Both measured and simulated results suggest that it is a possible candidate for the application of 5 G RF front-end at sub-6 GHz frequency band.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.61371009)the Fund from the Chinese Ministry of Science and Technology(Grant No.2014AA032703)
文摘This study presents two multimode stepped-impedance structures to design single-and dual-band filters. Transmission zeroes are introduced for the single-band filter by using dual-mode stepped-impedance resonators. The single-band filter with high selectivity is centered at 6.02 GHz and has a fractional bandwidth （FBW） of 25.6%. Four stubs （two low frequency and two high frequency ones） are connected to the rectangular patch in the center to construct a quadruple-mode resonator. The independent conditions of the center frequencies of the high and low bands of the resonator are analyzed. A dual-band filter, which operates at 1.53 GHz and 2.44 GHz with FWBs of 12.1% and 14.1%, respectively is designed. The single-and dual-band filters are both fabricated with double-sided YBCO films and they can be used in mobile and satellite communications.
文摘A high performance Balun BandPass Filter (BPF) with capacitively loaded multiple coupled lines with very simple structure is proposed in this paper, this structure realizes simultaneous size reduction and superior harmonic response suppression performance in bandpass filtering meanwhile good differential performance of the Balun. The theory of this structure for unbalanced input into balanced output has been studied in this paper and a proper Balun and BPF characteristic by the symmetric feeding and skew symmetric feeding have been obtained to prove the theory. The enter frequency of the fabricated Balun-BPF is operated at 2.45 GHz with 6.93% Fractional Band Width (FBW), and this frequency is used for Bluetooth and some other communication systems. The differences between the two outputs are 180°± 1.92° in phase and within 0.33 dB in magnitude. At f0, the amplitude imbalance and phase difference are within 0.25 dB and 180.86°, respectively. The measured frequency responses agree well with the simulated ones. With the theoretical analyses and practical results, it is shown that the proposed one has the advantages of simple structure, convenient analysis and good performance of both BPF and Balun.
文摘In this paper,a Slotted Stepped-Impedance Resonator (SSIR) is proposed.Due to the slots in the low-impedance section of the conventional SIR,the new resonator has a lower fundamental resonance f0 and can provide a potential finite transmission zero fz close to f0.Based on the proposed SSIR,a fourth-order Chebychev BandPass Filter (BPF) is designed at f0=1 GHz.The measured results show that a better than-65 dB rejection is achieved on both the lower and the upper stopband.Moreover,the new filter has a wide-30 dB rejection upper stopband from 1.13f0 to 6.52f0.The fabricated filter exhibits a size of The new filter has a planar topology and is easily integrated with modern portable communication systems.
基金Project supported by the National Natural Science Foundation of China(No.20201438)。
文摘A compact input-reflectionless balanced bandpass filter(BPF)with flexible bandwidth(BW)using a three-line coupled structure(TLCS)is presented in this paper.For the differential mode(DM),the TLCS is applied to achieve the bandpass response;meanwhile,the input coupled-feed line of the TLCS is reused in the input absorption network.This design shows a good fusion of the absorptive and BPF sections,effectively reducing the circuit size,and the BWs of the two sections that can be controlled separately result in a flexibly controllable DM response BW of the proposed input-reflectionless balanced BPF.Detailed analyses of the ratio of the two-part BWs have been given for the first time,which is vital for the passband flatness and reflectionless feature.In the codesign of this work,the input-reflectionless DM bandpass response can be optimized easily,while wideband common mode(CM)noise absorption is achieved by the input absorption network.To verify the design method,a prototype with a compact layout(0.52λ×0.36λ)is designed and measured in the 0-7.0 GHz range.The DM center frequency(f0)is 2.45 GHz with a measured 3 dB fractional bandwidth of 31.4%.The simulation and measurement results with good agreement are presented,showing good performance,e.g.,low insertion loss(0.43 dB),wide upper stopband for the DM bandpass response(over 20 dB rejection level up to 2.72f0),and wideband DM reflectionless and CM noise absorption(fractional absorption bandwidth of 285.7%).
基金supported in part by the National Defense Basic Scientific Research Program of China(Grant No.JCKYS2021DC05)in part by The Fund of Prospective Layout of Scientific Research for Nanjing University of Aeronautics and Astronautics(NUAA)。
文摘A liquid-loaded frequency tunable cavity bandpass filter (BPF) is presented. A dielectric fluidic material, dimethyl silicone oil (DSO) withexcellent thermophysical characteristics (working temperature from −50 ℃ to 180 ℃) and extremely low loss tangent is employed as a dielectric loading.The frequency reconfigurability of the proposed design is realized by altering the liquid level inside the cavity resonator. The filter achieves a widefrequency tuning range as well as a high Q factor. Moreover, this design shows significantly improved environmental suitability in extreme temperaturecases, outperforming the existing microfluidic-based RF devices using water or liquid metals. A four-pole tunable cavity bandpass filter is designed andverified. A cross-coupling structure comprising a metal loop structure is used to introduce transmission zeros in the proposed filter, which enhances theskirt selectivity and out-of-band rejections. We demonstrate that the center frequency of the proposed BPF can be tuned from 4.92 GHz to 6.16 GHz,and the filter achieves a high Q factor between 521 and 1527. The measured results agree well with simulated results.
基金supported by the Beijing Natural Science Foundation(8202036)。
文摘Compact dual-band bandpass filter(BPF)for the 5 th generation mobile communication technology(5 G)radio frequency(RF)front-end applications was presented based on multilayer stepped impedance resonators(SIRs).The multilayer dual-band SIR BPF can achieve high selectivity and four transmission zeros(TZs)near the passband edges by the quarter-wavelength tri-section SIRs.The multilayer dual-band SIR BPF is fabricated on a 3-layer FR-4 substrate with a compact dimension of 5.5 mm×5.0 mm×1.2 mm.The measured two passbands of the multilayer dual-band SIR BPF are 3.3 GHz-3.5 GHz and 4.8 GHz-5.0 GHz with insertion loss(IL)less than 2 dB respectively.Both measured and simulated results suggest that it is a possible candidate for the application of 5 G RF front-end at sub-6 GHz frequency band.
