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
In order to solve the problem that the quality factor （ Q factor） of the conventional defected ground structure （DGS）is not high and cannot produce a sharp resonant band, a novel S-slot DGS is presented. Compared ...In order to solve the problem that the quality factor （ Q factor） of the conventional defected ground structure （DGS）is not high and cannot produce a sharp resonant band, a novel S-slot DGS is presented. Compared with the conventional DGS, the proposed S-slot DGS has a much higher Q factor, a quite simpler layout and a steeper band rejection. Its equivalent circuit model is extracted by analyzing the transfer characteristics, and design parameters are calculated according to the deducted equations. Characteristics of this type of DGS are investigated with variable dimension parameters and an experiential method for the design of the S-slot DGS is summarized. Finally, a sample of a compact S-slot DGS unit resonated at 4. 64 GHz is fabricated. Its Q factor is as high as 39. 66 and its size is only 5.00 mm × 1.40 mm, with a steep resonant band and a low insertion-loss passband. The measured results show a good agreement with simulation, which demonstrates the applicability of the S-slot DGS in practical engineering.展开更多
The filter characteristic of defected ground structure (DGS) is analyzed and the equivalent circuit of C-shaped DGS is extracted. The characteristics of non-periodic and periodic DGS with different dimensions are comp...The filter characteristic of defected ground structure (DGS) is analyzed and the equivalent circuit of C-shaped DGS is extracted. The characteristics of non-periodic and periodic DGS with different dimensions are compared. Then the DGS is simulated and optimized with software, and the circuit board is manufactured and measured.The non-periodic structure is simple in structure and small in size and ripple compared with the periodic structure.Though the stop band of the non-periodic structure is narrow, it can meet the requirement of application. The C-shaped structure with two stop bands can select frequency in a special band.展开更多
A novel defected ground structure （DGS） for the microstrip line is proposed in this paper. The DGS lattice has more defect parameters so that it can provide better performance than the conventional dumbbell-shaped D...A novel defected ground structure （DGS） for the microstrip line is proposed in this paper. The DGS lattice has more defect parameters so that it can provide better performance than the conventional dumbbell-shaped DGS. Selectivity is improved by 97.2% with a sharpness factor of 24.6%. The method is applied to the design of a low-pass filter to confirm validity of the proposed DGS.展开更多
A compact low-profile dual-band Circularly Polarized(CP)microstrip antenna is proposed for the Bei Dou Navigation Satellite System(BDS).To achieve dual-band functionality,a single-layer multimode design is employed,in...A compact low-profile dual-band Circularly Polarized(CP)microstrip antenna is proposed for the Bei Dou Navigation Satellite System(BDS).To achieve dual-band functionality,a single-layer multimode design is employed,incorporating F-,L-,and T-shaped slots at the corners for CP performance.Additionally,a Defected Ground Structure(DGS)is implemented to further enhance the antenna's efficiency.A detailed parameter analysis is conducted to optimize the antenna's size and performance balance.After optimization,the final dimensions of the antenna are minimized while still meeting the design requirements.The prototype of the optimized antenna is fabricated and tested,demonstrating coverage of frequency bands from 1.182 GHz to 1.217 GHz and 1.547 GHz to 1.569 GHz.The antenna effectively supports dual-band CP for B1I and B2b frequency bands.A performance metric,the Ratio of relative Bandwidth to Volume(RBV),is introduced to evaluate the antenna's efficiency.Compared to similar designs,the proposed antenna offers a smaller size without sacrificing performance,making it well-suited for BDS airborne applications.展开更多
This paper presents a novel low-pass filter （LPF） with sharp rejection, wide stopband and compact size, which are realized by the defected ground structure （DGS） and the defected microstrip structure （DMS）. The ...This paper presents a novel low-pass filter （LPF） with sharp rejection, wide stopband and compact size, which are realized by the defected ground structure （DGS） and the defected microstrip structure （DMS）. The equivalent circuit model is proposed and the circuit parameters are extracted by the circuit simulation software. The parameters measured are 3 dB cutoff frequency fc of 5.2 GHz, the insertion loss less than 0.5 dB from DC to 4.0 GHz and S21 less than -20 dB within the wide stopband from 6 GHz to 16 GHz. The results of the circuit optimization agree well with those of the full wave simulation and the measured ones, which validate the effectiveness of the equivalent circuit model. The size of the proposed LPF is decreased compared with normal LPF. This LPF can be applied in rectennas to eliminate high order harmonics.展开更多
A new design for a transparent low-pass filter(LPF) using a flexible polyethylene terephthalate(PET) material and metallic copper was proposed in this paper. The transparent microstrip filter employs an asymmetric Π-...A new design for a transparent low-pass filter(LPF) using a flexible polyethylene terephthalate(PET) material and metallic copper was proposed in this paper. The transparent microstrip filter employs an asymmetric Π-shaped structure with dimensions of 260.000 mm×13.000 mm×0.148 mm, which owns a narrow transition band and achieves an insertion loss of less than 1.0 dB below 0.26 GHz. Furthermore, the insertion loss of the transparent microstrip filter can exceed 30 dB in the stopband from 1.02 GHz to 6.50 GHz. Square holes are added to the copper layer to improve the transparency of the LPF, and the filter performance can be adjusted by changing the square hole area and resolution. Additionally, multiple identical structures are cascaded to increase the insertion loss in the stopband while maintaining the passband. The transparent microstrip LPF has the characteristics of flexibility, high transparency, and significant insertion loss in the stopband, making it suitable for applications that require electromagnetic protection in a clear field of vision.展开更多
A structure-based microstrip passband filter with the center frequency of 2.6 GHz was put forward by using double-mode resonator based on defected ground structure （DGS） technology. A double-mode coupling resonator ...A structure-based microstrip passband filter with the center frequency of 2.6 GHz was put forward by using double-mode resonator based on defected ground structure （DGS） technology. A double-mode coupling resonator combined with DGS structure was used to achieve the resonance frequency and the filter size. CST microwave studio was used to optimize the attenuation performance to get the filter parameters. A structure-based passband filter was fabricated. Simulation is consistent with the measurement. Performance shows that the proposed filter could be suitable for the time division-long term devolution （TD-LTE） microwave systems at 2.6 GHz.展开更多
In this study we present the design and realization of a tunable dual band wireless power transfer(TDB-WPT)coupled resonator system.The frequency response of the tunable band can be controlled using a surface-mounted ...In this study we present the design and realization of a tunable dual band wireless power transfer(TDB-WPT)coupled resonator system.The frequency response of the tunable band can be controlled using a surface-mounted varactor.The transmitter(Tx)and the receiver(Rx)circuits are symmetric.The top layer contains a feed line with an impedance of 50Ω.Two identical half rings defected ground structures(HR-DGSs)are loaded on the bottom using a varactor diode.We propose a solution for restricted WPT systems working at a single band application according to the operating frequency.The effects of geometry,orientation,relative distance,and misalignments on the coupling coefficients were studied.To validate the simulation results,the proposed TDB-WPT system was fabricated and tested.The system occupied a space of 40 mm×40 mm.It can deliver power to the receiver with an average coupling efficiency of 98%at the tuned band from 817 to 1018 MHz and an efficiency of 95%at a fixed band of 1.6 GHz at a significant transmission distance of 22 mm.The results of the measurements accorded well with those of an equivalent model and the simulation.展开更多
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.
基金The National Natural Science Foundation of China(No60890071)the National High Technology Research and Development Program of China(863Program)(No2009AA01Z132)
文摘In order to solve the problem that the quality factor （ Q factor） of the conventional defected ground structure （DGS）is not high and cannot produce a sharp resonant band, a novel S-slot DGS is presented. Compared with the conventional DGS, the proposed S-slot DGS has a much higher Q factor, a quite simpler layout and a steeper band rejection. Its equivalent circuit model is extracted by analyzing the transfer characteristics, and design parameters are calculated according to the deducted equations. Characteristics of this type of DGS are investigated with variable dimension parameters and an experiential method for the design of the S-slot DGS is summarized. Finally, a sample of a compact S-slot DGS unit resonated at 4. 64 GHz is fabricated. Its Q factor is as high as 39. 66 and its size is only 5.00 mm × 1.40 mm, with a steep resonant band and a low insertion-loss passband. The measured results show a good agreement with simulation, which demonstrates the applicability of the S-slot DGS in practical engineering.
基金Supported by Natural Science Foundation of China(No.60371029).
文摘The filter characteristic of defected ground structure (DGS) is analyzed and the equivalent circuit of C-shaped DGS is extracted. The characteristics of non-periodic and periodic DGS with different dimensions are compared. Then the DGS is simulated and optimized with software, and the circuit board is manufactured and measured.The non-periodic structure is simple in structure and small in size and ripple compared with the periodic structure.Though the stop band of the non-periodic structure is narrow, it can meet the requirement of application. The C-shaped structure with two stop bands can select frequency in a special band.
基金Project supported by the Shanghai Leading Academic Discipline Project (Grant No.T0102)
文摘A novel defected ground structure （DGS） for the microstrip line is proposed in this paper. The DGS lattice has more defect parameters so that it can provide better performance than the conventional dumbbell-shaped DGS. Selectivity is improved by 97.2% with a sharpness factor of 24.6%. The method is applied to the design of a low-pass filter to confirm validity of the proposed DGS.
基金co-supported by the Natural Science Foundation of Tianjin,China(No.21JCZDJC00860)the Civil Aviation Security Capacity Building Funding Project,China(No.2020[142])。
文摘A compact low-profile dual-band Circularly Polarized(CP)microstrip antenna is proposed for the Bei Dou Navigation Satellite System(BDS).To achieve dual-band functionality,a single-layer multimode design is employed,incorporating F-,L-,and T-shaped slots at the corners for CP performance.Additionally,a Defected Ground Structure(DGS)is implemented to further enhance the antenna's efficiency.A detailed parameter analysis is conducted to optimize the antenna's size and performance balance.After optimization,the final dimensions of the antenna are minimized while still meeting the design requirements.The prototype of the optimized antenna is fabricated and tested,demonstrating coverage of frequency bands from 1.182 GHz to 1.217 GHz and 1.547 GHz to 1.569 GHz.The antenna effectively supports dual-band CP for B1I and B2b frequency bands.A performance metric,the Ratio of relative Bandwidth to Volume(RBV),is introduced to evaluate the antenna's efficiency.Compared to similar designs,the proposed antenna offers a smaller size without sacrificing performance,making it well-suited for BDS airborne applications.
文摘This paper presents a novel low-pass filter （LPF） with sharp rejection, wide stopband and compact size, which are realized by the defected ground structure （DGS） and the defected microstrip structure （DMS）. The equivalent circuit model is proposed and the circuit parameters are extracted by the circuit simulation software. The parameters measured are 3 dB cutoff frequency fc of 5.2 GHz, the insertion loss less than 0.5 dB from DC to 4.0 GHz and S21 less than -20 dB within the wide stopband from 6 GHz to 16 GHz. The results of the circuit optimization agree well with those of the full wave simulation and the measured ones, which validate the effectiveness of the equivalent circuit model. The size of the proposed LPF is decreased compared with normal LPF. This LPF can be applied in rectennas to eliminate high order harmonics.
基金supported by the National Natural Science Foundation of China (62271033)the Beijing Natural Science Foundation (8202036)。
文摘A new design for a transparent low-pass filter(LPF) using a flexible polyethylene terephthalate(PET) material and metallic copper was proposed in this paper. The transparent microstrip filter employs an asymmetric Π-shaped structure with dimensions of 260.000 mm×13.000 mm×0.148 mm, which owns a narrow transition band and achieves an insertion loss of less than 1.0 dB below 0.26 GHz. Furthermore, the insertion loss of the transparent microstrip filter can exceed 30 dB in the stopband from 1.02 GHz to 6.50 GHz. Square holes are added to the copper layer to improve the transparency of the LPF, and the filter performance can be adjusted by changing the square hole area and resolution. Additionally, multiple identical structures are cascaded to increase the insertion loss in the stopband while maintaining the passband. The transparent microstrip LPF has the characteristics of flexibility, high transparency, and significant insertion loss in the stopband, making it suitable for applications that require electromagnetic protection in a clear field of vision.
基金supported by the National Natural Science Foundation of China (61202399)
文摘A structure-based microstrip passband filter with the center frequency of 2.6 GHz was put forward by using double-mode resonator based on defected ground structure （DGS） technology. A double-mode coupling resonator combined with DGS structure was used to achieve the resonance frequency and the filter size. CST microwave studio was used to optimize the attenuation performance to get the filter parameters. A structure-based passband filter was fabricated. Simulation is consistent with the measurement. Performance shows that the proposed filter could be suitable for the time division-long term devolution （TD-LTE） microwave systems at 2.6 GHz.
文摘In this study we present the design and realization of a tunable dual band wireless power transfer(TDB-WPT)coupled resonator system.The frequency response of the tunable band can be controlled using a surface-mounted varactor.The transmitter(Tx)and the receiver(Rx)circuits are symmetric.The top layer contains a feed line with an impedance of 50Ω.Two identical half rings defected ground structures(HR-DGSs)are loaded on the bottom using a varactor diode.We propose a solution for restricted WPT systems working at a single band application according to the operating frequency.The effects of geometry,orientation,relative distance,and misalignments on the coupling coefficients were studied.To validate the simulation results,the proposed TDB-WPT system was fabricated and tested.The system occupied a space of 40 mm×40 mm.It can deliver power to the receiver with an average coupling efficiency of 98%at the tuned band from 817 to 1018 MHz and an efficiency of 95%at a fixed band of 1.6 GHz at a significant transmission distance of 22 mm.The results of the measurements accorded well with those of an equivalent model and the simulation.
