A novel millimeter-wave waveguide-to-microstrip transition based on magnetic-coupling is presented in this paper.The mode conversion of electromagnetic field is realized with the ring strip line of arbitrary shape in ...A novel millimeter-wave waveguide-to-microstrip transition based on magnetic-coupling is presented in this paper.The mode conversion of electromagnetic field is realized with the ring strip line of arbitrary shape in the E-plane of rectangular waveguide and the eccentric quasi-coaxial line,which is partially filled with media and consists of outer and inner rectangular conductors.The structure has the advantages of low loss,wide bandwidth,compact structure,and avoiding debug.From 27 GHz to 40 GHz,the experiment results show that the insertion loss is less than 1.2 dB and the return loss is better than 13.5 dB for the back-to-back transition with semicircle ring strip lines.展开更多
Three dual-mode band-pass filters are presented in the present paper. The first filter is realized by dual-mode substrate integrated waveguide (SIW) cavity;the second is based on the integration of SIW cavity with ele...Three dual-mode band-pass filters are presented in the present paper. The first filter is realized by dual-mode substrate integrated waveguide (SIW) cavity;the second is based on the integration of SIW cavity with electromagnetic band gap (EBG);and the third is based on the integration of SIW cavity with complementary split ring resonator (CSRR). The dual-mode SIW cavity is designed to have a fractional bandwidth of 4.95% at the midband frequency of 9.08 GHz;the proposed EBG-SIW resonator operates at 9.12 GHz with a bandwidth of 4.38% and the CSRR-SIW resonator operates at 8.66 GHz with a bandwidth of 2.54%. The proposed filters have the high Q-factors and generate a transmission zero in upper stopband, and these by the use of Rogers RT/duriod 5880 (tm).展开更多
A new waveguide to coaxial line transition adopted to microwave band is proposed in this paper.The configuration and design of the transition is studied. It has the merits of simplicity in structure, ease ofconstructi...A new waveguide to coaxial line transition adopted to microwave band is proposed in this paper.The configuration and design of the transition is studied. It has the merits of simplicity in structure, ease ofconstruction and repeatable performance, especially that the coaxial line is in the same direction with thewaveguide. At X band, the pass bandwidth of the transition is about 6%, and the insertion loss less than 1dB.展开更多
Control of the dissymmetry of circularly polarized luminescence(CPL)is intriguing and has great potential for applications in the field of optics.The traditional control strategy involves using the opposite enantiomer...Control of the dissymmetry of circularly polarized luminescence(CPL)is intriguing and has great potential for applications in the field of optics.The traditional control strategy involves using the opposite enantiomers to achieve reversal of CPL signs.However,regulating CPL reversal by controlling only the transition dipole moments without changing molecular or supramolecular chirality remains a challenge.Herein,we developed a couple of crystal materials based on axially chiral aggregation-induced emission luminogens(AIEgens).These materials exhibit achiral solvent-induced CPL sign inversion with identical helical structures and molecular chirality in their crystalline states.(R)-BPAuCz^(T)displays(+)-CPL with a dissymmetry factor of luminescence(glum)value of+9.81×10^(−4)(560 nm),while(R)-BPAuCz^(C)exhibits(−)-CPL with a glum value of−1.02×10^(−3)(560 nm).Time-dependent density functional theory calculations show that the magnetic and electric transition dipole moments at S_(1)→S_(0)of the(R)-BPAuCzC unit cell are considerably influenced by the cocrystallized solvent molecules,revealing a solvent-induced CPL inversion mechanism.The nonbonding interactions between the solvent molecules(i.e.,tetrahydrofuran or CDCl_(3))and AIEgens in the crystal play a crucial role in the manipulation of the transition dipole moment of these crystal materials.Moreover,microrods of(R)-BPAuCzT,(R)-BPAuCzC,and(R)-BPAuCzDCE exhibit optical waveguide properties with relatively low optical-loss coefficients of 187.3,567.4,and 65.2 dB/cm,respectively.These findings can help in developing a new strategy toward controlling CPL signals and providing a potential application for future integrated photonic circuits.展开更多
基金supported by the National Natural Science Foundation of China under Grant No.61001027the Fundamental Research Funds for the Central Universities under Grant No.ZYGX2010J046+2 种基金the Research on Millimeter Wave Waveguide-to-Microstrip Transition Technology under Grant No.H04010401W0409100supporting this research by the project of the Study on Electromagnetic Characteristics of Metamaterials under the Grant No.Y02002010401062the Foundation of Study on Characteristic of Chiral Metamaterials sponsored by the School of Physical Electronics,University of Electronic Science and Technology of China
文摘A novel millimeter-wave waveguide-to-microstrip transition based on magnetic-coupling is presented in this paper.The mode conversion of electromagnetic field is realized with the ring strip line of arbitrary shape in the E-plane of rectangular waveguide and the eccentric quasi-coaxial line,which is partially filled with media and consists of outer and inner rectangular conductors.The structure has the advantages of low loss,wide bandwidth,compact structure,and avoiding debug.From 27 GHz to 40 GHz,the experiment results show that the insertion loss is less than 1.2 dB and the return loss is better than 13.5 dB for the back-to-back transition with semicircle ring strip lines.
文摘Three dual-mode band-pass filters are presented in the present paper. The first filter is realized by dual-mode substrate integrated waveguide (SIW) cavity;the second is based on the integration of SIW cavity with electromagnetic band gap (EBG);and the third is based on the integration of SIW cavity with complementary split ring resonator (CSRR). The dual-mode SIW cavity is designed to have a fractional bandwidth of 4.95% at the midband frequency of 9.08 GHz;the proposed EBG-SIW resonator operates at 9.12 GHz with a bandwidth of 4.38% and the CSRR-SIW resonator operates at 8.66 GHz with a bandwidth of 2.54%. The proposed filters have the high Q-factors and generate a transmission zero in upper stopband, and these by the use of Rogers RT/duriod 5880 (tm).
文摘A new waveguide to coaxial line transition adopted to microwave band is proposed in this paper.The configuration and design of the transition is studied. It has the merits of simplicity in structure, ease ofconstruction and repeatable performance, especially that the coaxial line is in the same direction with thewaveguide. At X band, the pass bandwidth of the transition is about 6%, and the insertion loss less than 1dB.
基金support from the National Natural Science Foundation of China(52003298 and 22474155)the Natural Science Foundation of Jiangsu Province(BK20200578)+5 种基金F.Song acknowledges the start-up funding from the Beijing University of Technology(049000513202 and 049000514123564)the Beijing Outstanding Young Scientist Program(BJJWZYJH01201910005017)the Funding for Graduate Education(049000513205)the Research Grants Council of Hong Kong(C6014-20 W)the Innovation and Technology Commission(ITC-CNERC14SC01)the National Natural Science Foundation of China(22090023).
文摘Control of the dissymmetry of circularly polarized luminescence(CPL)is intriguing and has great potential for applications in the field of optics.The traditional control strategy involves using the opposite enantiomers to achieve reversal of CPL signs.However,regulating CPL reversal by controlling only the transition dipole moments without changing molecular or supramolecular chirality remains a challenge.Herein,we developed a couple of crystal materials based on axially chiral aggregation-induced emission luminogens(AIEgens).These materials exhibit achiral solvent-induced CPL sign inversion with identical helical structures and molecular chirality in their crystalline states.(R)-BPAuCz^(T)displays(+)-CPL with a dissymmetry factor of luminescence(glum)value of+9.81×10^(−4)(560 nm),while(R)-BPAuCz^(C)exhibits(−)-CPL with a glum value of−1.02×10^(−3)(560 nm).Time-dependent density functional theory calculations show that the magnetic and electric transition dipole moments at S_(1)→S_(0)of the(R)-BPAuCzC unit cell are considerably influenced by the cocrystallized solvent molecules,revealing a solvent-induced CPL inversion mechanism.The nonbonding interactions between the solvent molecules(i.e.,tetrahydrofuran or CDCl_(3))and AIEgens in the crystal play a crucial role in the manipulation of the transition dipole moment of these crystal materials.Moreover,microrods of(R)-BPAuCzT,(R)-BPAuCzC,and(R)-BPAuCzDCE exhibit optical waveguide properties with relatively low optical-loss coefficients of 187.3,567.4,and 65.2 dB/cm,respectively.These findings can help in developing a new strategy toward controlling CPL signals and providing a potential application for future integrated photonic circuits.
