- 标题
- 摘要
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- 实验方案
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Bandstop Frequency-Selective Structures Based on Stepped-Impedance Loop Resonators: Design, Analysis and Measurement
摘要： A new dual-polarized and dual-band second-order bandstop 3-D frequency-selective structure (FSS) is proposed with arbitrary band ratio. Compared with the square loop, the stepped-impedance loop resonator performs at a lower basic resonant frequency and increases the first spurious resonant frequency. Different half-wavelength stepped-impedance loop resonators are analyzed, compared and employed to design single /dual-band 3-D FSSs under TE polarization. A double-sided stepped-impedance loop resonator with via holes is presented for constructing a dual-polarized single-band FSS. By adjusting widths of low characteristic impedance sections, the FSS’s band can be expanded into dual bands. Detailed analysis of the coupling between both identical resonators in series is provided for understanding the relationships between sub-resonators. In addition, the equivalent circuit models are developed to explain the operating principle and analyze parameter effects. The proposed FSS prototype is fabricated and then measured to verify the design methodology. The measured results agree with the simulated data and exhibit a dual-polarized and stable second-order bandstop response under different incident angles up to 30o. The thickness of the structure is 23% of the free-space wavelength at the first center frequency, and the center frequency ratio of both stopbands is only 1.08.
关键词： Stepped-impedance loop resonator,Bandstop,Equivalent circuit model,3-D frequency-selective structure,Coupling
更新于2025-09-10 09:29:36
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Compact Scalable Modeling of Chipless RFID Tag Based on High-Impedance Surface
摘要： This paper proposes a compact model for chipless radio frequency identification (RFID) tag. This compact scalable model consists of capacitors, inductors, and resistors of which their values are directly described by the physical dimension of the chipless tag. Moreover, based on this compact model, radar cross section of chipless RFID tag is predicted, by analyzing polarizability based on surface current distribution in different modes. To validate the proposed model, a 5-bit chipless RFID tag based on high-impedance surface (HIS) is presented, with good agreement among modeled, simulated, and measured results. A wide range of physical parameters have also been validated to show the scalability. This compact scalable model of chipless RFID tag not only simplifies the tag design, but also provides an insight understanding of the HIS structure.
关键词： radar cross section (RCS),high-impedance surface (HIS),equivalent circuit modeling,Chipless radio frequency identification (RFID) tag,surface current distribution
更新于2025-09-10 09:29:36
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Hydrodynamic response model of a piezoelectric inkjet print-head
摘要： The concentric squeeze-mode piezoelectric print-head (PPH) has been applied to the field of additive manufacturing, which requires a high deposition precision of droplets. To combine the self-sensing technique of a PPH, this paper presents a linear time-varying system equivalent circuit model based on radial displacement. This system is able to predict the flow state in the channel according to the variation of the pipe diameter. Compared with current models, this equivalent circuit model is more accurate in regard to energy attenuation. The equivalent thickness of the boundary layer is presented using a combination of boundary layer theory and oscillating plate flow to calculate the equivalent resistance of the viscous force. The experimental results show that the proposed method is more precise than the previous equivalent methods. To verify the model, a single trapezoidal pulse waveform and double trapezoidal pulse waveform were designed to realize the superposition of pressure and suppression of residual oscillation, respectively. The experimental results showed that the single trapezoidal pulse waveform based on the modelled pressure response was able to exactly realize the superposition of pressure and that the double trapezoidal pulse waveform based on the modelled pressure response was able to suppress the residual oscillation. The pressure and volume flow rate responses of the model are highly consistent with the experimental results in the time domain.
关键词： time-varying system,equivalent circuit,piezoelectric print-head
更新于2025-09-10 09:29:36
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Electromagnetic modeling and design of a novel class of complementary split-ring resonators
摘要： This research study reports the assessment of complementary split ring resonators based on Gielis transformation as basic elements for the design of high-performance microwave components in printed technology. From the electromagnetic simulation of said structures, suitable equivalent circuit models are extracted and analyzed. Physical prototypes are fabricated and tested for design validation. The obtained results confirm that the adoption of supershaped geometries enables the synthesis of very compact scalable microwave filters.
关键词： Gielis formula,equivalent circuit,complementary split-ring resonator,microwave filter,metamaterials
更新于2025-09-09 09:28:46
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HIGH IMPEDANCE PROPERTIES OF TWO-DIMENSIONAL COMPOSITE RIGHT/LEFT-HANDED TRANSMISSION LINES
摘要： The electromagnetic characteristics of two-dimensional composite right/left-handed transmission lines (2D CRLH TLs) were investigated for the normal incidence of plane waves. The measured characteristic impedance and re?ection phases exhibited resonant high impedance properties (equivalent to zero re?ection phase) at a frequency within the left-handed mode for one-dimensional CRLH TL. An equivalent circuit was proposed to explain the measured characteristics. The relationship between the resonant frequency and the circuit parameters for 2D CRLH TLs was clari?ed by deriving an approximate equation for the resonant frequency.
关键词： equivalent circuit,plane waves,resonant frequency,two-dimensional composite right/left-handed transmission lines,high impedance properties
更新于2025-09-09 09:28:46
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A MINIATURIZED BANDPASS FREQUENCY SELECTIVE SURFACE WITH HIGH SELECTIVITY BASE ON SLOT COUPLING
摘要： A Ku-band bandpass frequency selective surface (FSS) with high selectivity and miniaturization is proposed in this paper. We use two metallic strips and one slot to design the frequency selective surface structure which contains both electrical and magnetic couplings. A metallic via is introduced in the FSS element for miniaturization. With the via inserted at the end of the metallic strip, the FSS unit size is reduced to half compared to that without via inserted. To investigate the operating principle of the slot-coupled FSS, an equivalent-circuit model is given and analysed using the odd- and even-mode method. The constructed out-of-phase signal path causes two transmission zeros (TZs) near the skirts of the narrow pass band, thereby enhancing the selectivity. A prototype of the proposed FSS operating at 16 GHz is fabricated and measured. The measured results agree well with the full-wave and circuit simulation results, thus verifying the FSS design.
关键词： slot coupling,Ku-band,bandpass frequency selective surface,metallic via,high selectivity,equivalent-circuit model,transmission zeros,miniaturization
更新于2025-09-09 09:28:46
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[IEEE 2018 48th European Microwave Conference (EuMC) - Madrid, Spain (2018.9.23-2018.9.27)] 2018 48th European Microwave Conference (EuMC) - Design of a Wideband Multilayer Meander-Line Polarizer (6 – 18 GHz) using a Semi-Analytical Method
摘要： A semi-analytical method to design multilayer meander-line polarizers is described in this paper. The proposed procedure consists of a combination of the transmission line equivalent circuit and a Simulated Annealing Algorithm to estimate the best values of the dimensions of the polarizer. A wideband four layers’ meander-line polarizer [6 – 18 GHz] is studied. Patch antenna resonating at different frequencies is associated to the polarizer to validate it. The results verify that the proposed multilayer meander-line polarizer convert the Linear wave to Circular one.
关键词： Simulated Annealing Algorithm,Transmission-Line Equivalent Circuit,Meander-line Polarizer,Linear polarization,Wideband Polarizer,Multilayer Structure,Circular polarization
更新于2025-09-09 09:28:46
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MUTUAL COUPLING REDUCTION BETWEEN PRINTED DUAL-FREQUENCY ANTENNA ARRAYS
摘要： A new defected ground structure (DGS) is designed to reduce the mutual coupling of a dual-frequency printed monopole array. The designed dual-frequency DGS consists of two concentric split ring slots. Each split ring slot produces band rejection characteristics at one resonant frequency of the antennas. An e?ective equivalent circuit model of the DGS section is proposed with the circuit parameters successfully extracted. Good agreement exists among the circuit simulation, EM simulation and experimental results. With the inclusion of the DGS, the measured mutual coupling of the dual-band array has been e?ectively reduced by 10 dB and 20 dB at two resonant frequencies, respectively.
关键词： dual-frequency printed monopole array,equivalent circuit model,defected ground structure (DGS),mutual coupling reduction
更新于2025-09-09 09:28:46
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[IEEE 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Chengdu, China (2018.5.7-2018.5.11)] 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Design of Wideband Circuit Analog Absorber with Improved Oblique Incidence Performance
摘要： Most of the previous circuit analog (CA) absorbers only consider the normal incidence. In this paper, a novel wideband absorber consisting of two dimensional array of conductive crossed dipoles with lumped resistors and a well-designed dielectric, working as the wide-angle impedance matching (WAIM) layer, is presented. Results show that the absorption under oblique transverse electrical (TE) incidence can be markedly improved due to the WAIM layer. Equivalent circuit (EC) and strict formula derivation are proposed to make the design more clear and straightforward. Evolutionary algorithm, to be specific, the differential evolution, is used to speed up the optimization process. The final results obtained by EC and simulation software show that the absorber offers the 10-dB reflection reduction bandwidth of at least 109.6%(2.6-8.9 GHz) when the angle of TE incidence is less than 60 degrees.
关键词： differential evolution (DE),microwave absorber,Circuit analog (CA) absorber,equivalent circuit
更新于2025-09-04 15:30:14
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Modeling and Experimental Analysis on the Temperature Response of AlN-Film Based SAWRs
摘要： The temperature responses of aluminum nitride (AlN) based surface acoustic wave resonator (SAWR) are modeled and tested. The modeling of the electrical performance is based on a modified equivalent circuit model introduced in this work. For SAWR consisting of piezoelectric film and semiconducting substrate, parasitic parameters from the substrate is taken into consideration for the modeling. By utilizing the modified model, the high temperature electrical performance of the AlN/Si and AlN/6H-SiC based SAWRs can be predicted, indicating that a substrate with a wider band gap will lead to a more stable high temperature behavior, which is further confirmed experimentally by high temperature testing from 300 K to 725 K with SAWRs having a wavelength of 12 μm. Temperature responses of SAWR’s center frequency are also calculated and tested, with experimental temperature coefficient factors (TCF) of center frequency being ′29 ppm/K and ′26 ppm/K for the AlN/Si and AlN/6H-SiC based SAWRs, which are close to the predicted values.
关键词： equivalent circuit modeling,aluminum nitride,surface acoustic resonators,high temperature response
更新于2025-09-04 15:30:14