With the rapid development of wireless techniques,the bandpass filter(BPF)is required to cover microwave and millimeter-wave frequency bands simultaneously with good mid-band suppression.However,it is difficult to imp...With the rapid development of wireless techniques,the bandpass filter(BPF)is required to cover microwave and millimeter-wave frequency bands simultaneously with good mid-band suppression.However,it is difficult to implement such BPF due to the large frequency ratio and wideband rejection.This paper presents a superior method to realize a dual-band BPF with a large frequency ratio maintaining compact size and low design complexity.This is contributed by an ultra-wide stopband BPF with inherent discriminating excited degree at spurious frequencies.By properly arranging the feeding position and electrical length ratio of stepped impedance resonator(SIR),the excited degree at specific spurious frequencies can be flexibly adjusted to achieve desired suppression level without affecting characteristics at the fundamental passband.For validation,two BPFs were simulated,fabricated and measured,exhibiting suppression levels of 20.3 dB and 35 dB up to 18f0 and 10.53f0 respectively.Based on this,a dual-band BPF with a large frequency ratio can be easily constructed.For demonstration,a dual-band BPF operating at 3.55 GHz and 43.15 GHz is implemented.A frequency ratio up to 12.15 and mid-band suppression level better than 28 dB had been achieved.Advantages of compactness,simplicity and excellent performance of the proposed work can be observed.展开更多
In this study, a novel self-embedding asymmetric stepped impedance resonator （SE-ASIR） topology is proposed. By embedding asymmetric stepped impedance resonators in themselves, circuit sizes of ASIRs can be reduced ...In this study, a novel self-embedding asymmetric stepped impedance resonator （SE-ASIR） topology is proposed. By embedding asymmetric stepped impedance resonators in themselves, circuit sizes of ASIRs can be reduced effectively, while the ability to control spurious modes of ASIRs remains. Therefore, SE-ASIRs are suitable for being used to design filters with wide stopbands and miniaturized sizes. Furthermore, the construction process of the SE-ASIR is described in detail, and an equivalent model of the SE-ASIR is proposed. For demonstration, a high-temperature superconducting bandpass filter centered at 1112 MHz is designed and fabricated. The measured result agrees well with the simulation result and shows that the out-of-band rejection is better than 60 dB up to 4088 MHz, which is about 3.7 times the center frequency. The filter circuit size is 31 mm × 13 mm or 0.28λg × 0.12λg, where g is the guided wavelength at 1112 MHz.展开更多
In this study, we propose a novel resonator that is composed of a modified spiral with an embedded interdigital capacitor. A large ratio of the first spurious frequency to the fundamental resonant frequency is obtaine...In this study, we propose a novel resonator that is composed of a modified spiral with an embedded interdigital capacitor. A large ratio of the first spurious frequency to the fundamental resonant frequency is obtained, which is suitable for the design of filters with wide stopbands, and the circuit size is considerably reduced by embedding the interdigital structure in the spiral. For demonstration, a compact four-pole high temperature superconducting（HTS） filter with a center frequency of 568 MHz is designed and fabricated on double-sided YBCO film with a size of 11.4 mm×8.0 mm. The filter measurement shows excellent performance with an out-of-band rejection level better than 60.9 dB up to 3863 MHz.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 miniaturized diplexer with a wide-stopband based on half-mode substrate integrated waveguide(HMSIW)is proposed.The diplexer combines a dual-mode resonator(DMR)with single-mode resonators(SMRs).The employment of HMSI...A miniaturized diplexer with a wide-stopband based on half-mode substrate integrated waveguide(HMSIW)is proposed.The diplexer combines a dual-mode resonator(DMR)with single-mode resonators(SMRs).The employment of HMSIW technology breaks through the limitations of SMRs on miniaturization,while effectively addressing the limitation on wide-stopband performance that is typically encountered with the TE202 mode in the SMRs.A second-order prototype,centered at 10.34 GHz and 13.90 GHz,has been designed and fabricated,using a TE_(i01)/TE_(301) DMR.展开更多
Narrow bandpass filters(NBPFs)play important roles in optics,such as quantum communication,spectrometer,and wavelength division multiplexing.However,the stopband and restraint ability of traditional NBPFs is limited.I...Narrow bandpass filters(NBPFs)play important roles in optics,such as quantum communication,spectrometer,and wavelength division multiplexing.However,the stopband and restraint ability of traditional NBPFs is limited.In this article,a coupled Tamm plasmon polaritons(TPPs)induced transmission theory has been proposed to design high-efficiency NBPFs with ultra-wide deep stopbands.An NBPF at 1.55 μm has been experimentally demonstrated with full width at half maximum(FWHM)of 10 nm and stopband ranging from 0.2 to 25 μm which is 62 times wider than that of traditional ones.Furthermore,the restraint depth of the stopband reaches 0.03%,which is only 1/20 of a traditional filter with the same FWHM.Its advantage in restraining ambient light over traditional ones has also been demonstrated with an InGaAs infrared detector.It provides a very powerful way to capture specific narrowband optical signals from ultra-wide strong ambient light,especially useful for daytime quantum communications.展开更多
This paper presents a novel approach to design a compact circular rat-race coupler with an ultrawide stopband, with the aim to reduce its size while maintaining performance. The design methodology begins with a common...This paper presents a novel approach to design a compact circular rat-race coupler with an ultrawide stopband, with the aim to reduce its size while maintaining performance. The design methodology begins with a common miniaturization technique to replace the conventional quarter-wavelength transmission line with an equivalent low-pass filter loaded with parallel coupled line and radial stubs. Since the latter leads to produce higher order harmonics, parasitic open-ended stubs are then properly introduced in the structure not only to overcome the issue but also to produce controllable transmission zeros. A versatile analytical model is also developed taking into account manufacturing restrictions, which makes it possible to extract the physical parameters of the coupler unit-cell for a given desired compactness percentage with respect to the conventional rat-race coupler. A prototype is fabricated and measured to validate the design,demonstrating the predicted behavior fairly achieved by numerical analysis. A significant size reduction of about 86.1% was achieved compared to the conventional design, while effectively suppressing higher order modes up to 23.4 GHz(including the 13th harmonic based on |S11|>-5 dB and |S21|<-17 dB)with high isolation level(|S41|<-17 dB) between the ports.展开更多
A compact high-scanning-rate circular-polarized leaky-wave antenna(LWA)based on a meandering substrate integrated waveguide(SIW)with defected ground structures(DGSs)is presented.The meandering-SIW design is employed t...A compact high-scanning-rate circular-polarized leaky-wave antenna(LWA)based on a meandering substrate integrated waveguide(SIW)with defected ground structures(DGSs)is presented.The meandering-SIW design is employed to enhance the beam scanning rate,while circular polarization is achieved by etchingπ-shaped slots on the top plane.To suppress the open stopband at broadside,offset circular DGSs are periodically etched on the ground plane.Their impact on the reflection coefficient and axial ratio is then analyzed through a parametric study.A prototype of the antenna is simulated,fabricated,and measured.Both simulated and measured results indicate a scanning rate of approximately 8.6,with continuous beam scanning from-41°to 59°across the 11.3-12.7 GHz operating band.The antenna maintains an axial ratio below 3 dB within the 11.5-12.3 GHz range.This design shows promise for use in wireless communication systems,particularly in environments with increasingly limited spectrum resources.展开更多
基金supported by the National Natural Science Foundation of China(No.61671485).
文摘With the rapid development of wireless techniques,the bandpass filter(BPF)is required to cover microwave and millimeter-wave frequency bands simultaneously with good mid-band suppression.However,it is difficult to implement such BPF due to the large frequency ratio and wideband rejection.This paper presents a superior method to realize a dual-band BPF with a large frequency ratio maintaining compact size and low design complexity.This is contributed by an ultra-wide stopband BPF with inherent discriminating excited degree at spurious frequencies.By properly arranging the feeding position and electrical length ratio of stepped impedance resonator(SIR),the excited degree at specific spurious frequencies can be flexibly adjusted to achieve desired suppression level without affecting characteristics at the fundamental passband.For validation,two BPFs were simulated,fabricated and measured,exhibiting suppression levels of 20.3 dB and 35 dB up to 18f0 and 10.53f0 respectively.Based on this,a dual-band BPF with a large frequency ratio can be easily constructed.For demonstration,a dual-band BPF operating at 3.55 GHz and 43.15 GHz is implemented.A frequency ratio up to 12.15 and mid-band suppression level better than 28 dB had been achieved.Advantages of compactness,simplicity and excellent performance of the proposed work can be observed.
基金supported by the National Natural Science Foundation of China(Grant No.61371009)the National High Technology Research and Development Program of China(Grant No.2014AA032703)
文摘In this study, a novel self-embedding asymmetric stepped impedance resonator （SE-ASIR） topology is proposed. By embedding asymmetric stepped impedance resonators in themselves, circuit sizes of ASIRs can be reduced effectively, while the ability to control spurious modes of ASIRs remains. Therefore, SE-ASIRs are suitable for being used to design filters with wide stopbands and miniaturized sizes. Furthermore, the construction process of the SE-ASIR is described in detail, and an equivalent model of the SE-ASIR is proposed. For demonstration, a high-temperature superconducting bandpass filter centered at 1112 MHz is designed and fabricated. The measured result agrees well with the simulation result and shows that the out-of-band rejection is better than 60 dB up to 4088 MHz, which is about 3.7 times the center frequency. The filter circuit size is 31 mm × 13 mm or 0.28λg × 0.12λg, where g is the guided wavelength at 1112 MHz.
基金supported by the National Key Scientific Instrument and Equipment Development Project,China(Grant No.2014YQ030975)the National Natural Science Foundation of China(Grant Nos.61371009 and 61401282)
文摘In this study, we propose a novel resonator that is composed of a modified spiral with an embedded interdigital capacitor. A large ratio of the first spurious frequency to the fundamental resonant frequency is obtained, which is suitable for the design of filters with wide stopbands, and the circuit size is considerably reduced by embedding the interdigital structure in the spiral. For demonstration, a compact four-pole high temperature superconducting（HTS） filter with a center frequency of 568 MHz is designed and fabricated on double-sided YBCO film with a size of 11.4 mm×8.0 mm. The filter measurement shows excellent performance with an out-of-band rejection level better than 60.9 dB up to 3863 MHz.
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supported by the National Natural Science Foundation of China(Nos.U23A20291 and 62021004)the National Key Research and Development Program of China(No.2023YFF0616600)。
文摘A miniaturized diplexer with a wide-stopband based on half-mode substrate integrated waveguide(HMSIW)is proposed.The diplexer combines a dual-mode resonator(DMR)with single-mode resonators(SMRs).The employment of HMSIW technology breaks through the limitations of SMRs on miniaturization,while effectively addressing the limitation on wide-stopband performance that is typically encountered with the TE202 mode in the SMRs.A second-order prototype,centered at 10.34 GHz and 13.90 GHz,has been designed and fabricated,using a TE_(i01)/TE_(301) DMR.
基金This work was funded by the National Natural Science Foundation of China(NSFC)(No.11874376)Shanghai Science and Technology Foundations(Nos.19DZ2293400,19ZR1465900,and 21WZ2504800)+3 种基金Shanghai Municipal Science and Technology Major Project(No.2019SHZDZX01)the Chinese Academy of Sciences President’s International Fellowship Initiative(Nos.2020VTA0009,2020PT0020,and 2021PT0007)And thanks to the support of Soft Matter Nanofab(No.SMN180827)Analytical Instrumentation Center(No.#SPST-AIC10112914)(SPST,ShanghaiTech University).
文摘Narrow bandpass filters(NBPFs)play important roles in optics,such as quantum communication,spectrometer,and wavelength division multiplexing.However,the stopband and restraint ability of traditional NBPFs is limited.In this article,a coupled Tamm plasmon polaritons(TPPs)induced transmission theory has been proposed to design high-efficiency NBPFs with ultra-wide deep stopbands.An NBPF at 1.55 μm has been experimentally demonstrated with full width at half maximum(FWHM)of 10 nm and stopband ranging from 0.2 to 25 μm which is 62 times wider than that of traditional ones.Furthermore,the restraint depth of the stopband reaches 0.03%,which is only 1/20 of a traditional filter with the same FWHM.Its advantage in restraining ambient light over traditional ones has also been demonstrated with an InGaAs infrared detector.It provides a very powerful way to capture specific narrowband optical signals from ultra-wide strong ambient light,especially useful for daytime quantum communications.
文摘This paper presents a novel approach to design a compact circular rat-race coupler with an ultrawide stopband, with the aim to reduce its size while maintaining performance. The design methodology begins with a common miniaturization technique to replace the conventional quarter-wavelength transmission line with an equivalent low-pass filter loaded with parallel coupled line and radial stubs. Since the latter leads to produce higher order harmonics, parasitic open-ended stubs are then properly introduced in the structure not only to overcome the issue but also to produce controllable transmission zeros. A versatile analytical model is also developed taking into account manufacturing restrictions, which makes it possible to extract the physical parameters of the coupler unit-cell for a given desired compactness percentage with respect to the conventional rat-race coupler. A prototype is fabricated and measured to validate the design,demonstrating the predicted behavior fairly achieved by numerical analysis. A significant size reduction of about 86.1% was achieved compared to the conventional design, while effectively suppressing higher order modes up to 23.4 GHz(including the 13th harmonic based on |S11|>-5 dB and |S21|<-17 dB)with high isolation level(|S41|<-17 dB) between the ports.
文摘A compact high-scanning-rate circular-polarized leaky-wave antenna(LWA)based on a meandering substrate integrated waveguide(SIW)with defected ground structures(DGSs)is presented.The meandering-SIW design is employed to enhance the beam scanning rate,while circular polarization is achieved by etchingπ-shaped slots on the top plane.To suppress the open stopband at broadside,offset circular DGSs are periodically etched on the ground plane.Their impact on the reflection coefficient and axial ratio is then analyzed through a parametric study.A prototype of the antenna is simulated,fabricated,and measured.Both simulated and measured results indicate a scanning rate of approximately 8.6,with continuous beam scanning from-41°to 59°across the 11.3-12.7 GHz operating band.The antenna maintains an axial ratio below 3 dB within the 11.5-12.3 GHz range.This design shows promise for use in wireless communication systems,particularly in environments with increasingly limited spectrum resources.
