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1.
为了降低广泛应用于光通信系统的光环行器的制造成本和占空比,增强系统中各器件的功能复用,提出一种功能复用反射式光环行器设计方案,利用透镜和反射镜组成光的空间交叉功能来实现功能复用以及光束方向传输引导,从而达到反射式光环行器输入 输出多尾纤之间的对应耦合。利用琼斯矩阵,从理论上对其主要性能进行了分析。分析结果表明,设计的光环行器在功能复用基础上具有低插入损耗、高隔离等特性,达到了光环行器的性能指标,在低插入损耗、高隔离的基础上具有功能复用效用。 相似文献
2.
Based on the scatter matrix of the four-port lossless mismatched circulator, the phase differential equation of the injection-locked magnetron is derived by comparing different effects of the mismatched and perfect circulator on the injection ratio. Besides, the locking range of the injection-locked magnetron with the mismatched circulator is deduced by functional operation. In addition, the phase differential equation and the locked bandwidth of the injection-locked system with a mismatched circulator are compared with those of the small injection-ratio case with a perfect circulator. The influence of the circulator reflection coefficient on the injection-locked magnetron is also analyzed by numerical calculation.Theoretical analysis shows that the decrement of the locked bandwidth is less than 1% and decrement of the stable phase difference is less than 1.2% when the reflection coefficient is less than 0.1. 相似文献
3.
《中国光学快报(英文版)》2017,(11)
A novel H-plane cross-shaped circulator based on magneto-photonic crystals is experimentally investigated.The band gap of the TE mode for the photonic crystals is calculated by the plane wave expansion method.The transmission characteristics of the circulator are simulated by the finite element method.We perform the experiments in the microwave regime to validate the numerical results.At the central frequency of 10.15 GHz,the measured isolation and insertion loss of the circulator reaches-30.2 and-3.93 d B,respectively.The bandwidth of the circulator is about 550 MHz.The optimal experimental value of isolation is higher than the numerical value. 相似文献
4.
基于叠层片式化结构对工作于S波段的低温共烧陶瓷(LTCC)铁氧体环行器进行设计和分析,模拟研究了器件制备中面临的关键问题对器件频率特性的影响。研究结果表明,采用微波铁氧体层与陶瓷介质层构成混合结构,匹配电路以三维方式进行布线和互联,器件可以获得优良的带内特性。在器件的三维电路布线中,当连接两节阻抗线的导体圆柱端口气隙高度达到20 m时,器件的传输特性和隔离特性急剧恶化。此外,研究还发现微波铁氧体层与陶瓷介质层出现分层时,形成的气隙高度不应大于20 m,否则将导致器件的传输特性和隔离特性显著降低。因此,在进行LTCC铁氧体环行器的制备时,导体圆柱与陶瓷介质层以及微波铁氧体层与陶瓷介质层的异质材料匹配共烧是保障器件优良性能的关键。 相似文献
5.
Guotai Chen Hong-sheng Yang Yaozhong Xu 《International Journal of Infrared and Millimeter Waves》2003,24(1):25-34
In this paper, a new type of W band circular waveguide Y-junction circulator is presented. The structure of this type of Y-junction is a cylindrical cavity connecting with three circular waveguides. The performances of the type of circulator are analyzed by the edge-based vector finite element method hybridized with the modal expansion. The numerical results show that this type of waveguide Y junction circulator has good circulation performance. 相似文献
6.
采用叠层片式化设计有望实现微波环形器与低温共烧陶瓷(LTCC)技术的结合。借助三维电磁仿真手段设计了一种X波段微带铁氧体环行器,基片采用具有不同饱和磁化强度的旋磁材料构成叠层片式结构。研究结果表明,叠片数目及其饱和磁化强度的搭配对环形器的回波损耗和隔离度特性影响显著,这与叠层结构引入的界面及叠片变化的饱和磁化强度影响了环形器的等效输入电路参数有关。通过优化设计,可以获得具有高回波损耗、高隔离度及低插入损耗等优良性能的器件,但带宽受叠片数目及其饱和磁化强度的搭配影响较小,难以通过优化进行拓展。 相似文献
7.
8.
M. R. Webb 《International Journal of Infrared and Millimeter Waves》1991,12(1):45-63
A four-port quasi-optical circulator has been designed, built and tested for operation in the millimetre wave band. The specific circulator reported here was investigated over a 20 GHz bandwidth, centred on 94 GHz. Good performance characteristics were obtained over this bandwidth. Isolations of better than 30 dB and insertion losses of around 0.5 dB were achieved. The input vswr was found to be less than 1.35 over the whole bandwidth investigated and vswr's of less than 1.1 were achieved for narrower bandwidths. It is possible of course to configure the 4-port circulator as a 3-port circulator or indeed as 2-port isolator. Further optimization and consequent improvements in performance are almost certainly obtainable. 相似文献
9.
Punya Prasanna Paltani 《Optik》2011,122(5):464-466
We show that by exploiting unequal magnitude of cross phase modulation (XPM) in co-propagating and counter-propagating beams, an all-optical circulator (AOC) using a nonlinear Mach-Zehnder Interferometer (MZI) could be constructed. The proposed circulator is novel, simple and polarization independent. 相似文献
10.
Deng-Guo Zhang Edward Kai-Ning Yung 《International Journal of Infrared and Millimeter Waves》2000,21(1):123-131
An H-plane waveguide Y-junction circulator with a triangular ferrite post is investigated by a modified analysis of jointly resonance theory and simple field theory. Good agreement between the theoretical obtained performances and experimental results is observed. The circulator exhibits a very low insertion loss and a wide bandwidth. 相似文献
11.
R. S. Chen Edward K. N. Yung Fei Ji W. B. Dou 《International Journal of Infrared and Millimeter Waves》2003,24(5):813-828
In this paper, a novel microstrip circulator with a magnetized ferrite sphere is proposed for various millimeter wave communications. A three-dimensional Finite-Difference Time-Domain (FDTD) approach for the analysis of this ferrite sphere based microstrip circulator is first presented. The electromagnetic fields inside the ferrite junction are calculated using special updating equations derived from the equation of motion of the magnetization vector and Maxwell's curl equations in consistency. Frequency dependent insertion loss, isolation and reflection loss of circulator are calculated over a wide band of frequencies with a single FDTD run. Experimental results at Ka band are presented and compared with theoretical simulations. As a result, a good agreement is found between them. 相似文献
12.
A Ka-band microstrip circulator, using ferrite with 4 M=5000 G, have been developed. By optimizing the circulator configuration, broadband n=2 Chebyshev response performance are obtained over 7 GHz bandwidth. The circulator have isolation of greater than 15 dB, and insertion loss of less than 1.0 dB. 相似文献
13.
A three-port optical circulator of W-format based on 2D photonic crystal is presented. This circulator is more compact as compared to the known one of the traditional Y-format. The W-circulator does not have rotational symmetry. As a consequence, the frequency responses for different port excitation are slightly different, as it is shown by symmetry analysis and by numerical simulations. 相似文献
14.
Ma Hong Qi Lanfen Zhu Mingli 《International Journal of Infrared and Millimeter Waves》1993,14(2):311-317
A new type of E-plane Y-junction circulator has been developed based on the nonradiative dielectric waveguide (NRD-guide) in Ka- band. First, the circulation principle has been analysed by the theory of polarization wave. The field components in the nonreciprocal Y-junction zone and the conclusion of 60° phase difference between clockwise and counterclockwise rotating polarization modes has been obtained. And then, the resonant frequency of the non-dc biased triangle ferrite sample has also been calculated. This kind of structure is benefit to enlarge the bandwidth of the Y-junction circulator. As an example, we had designed and fabricated a circulator in Ka-band. Its operating frequency is 35. 1GHz, the 1.5dB insertion loss and 20dB isolation bandwidth is about 1. 0GHz. 相似文献
15.
This study develops an alternative type of 4-port polarization-independent wavelength-interleaving bidirectional circulator. In this circulator the even- and odd-channels circulate with opposite handedness regardless of the state of polarization of signals. It has a pair of orthogonal holographic spatial- and polarization modules (HSPMs) and a Lyot-Ohman filter (LOF). Each HSPM has two holographic spatial walk-off polarizers (HSWPs), two glass plates and two half-wave plates. The function of the HSWP is firstly described. Next, the structures and the operating principles of the HSPM and the LOF are also described. Then, the operating principle and the performance of this circulator are discussed. It has such merits as polarization-independence, compactness, high isolation, lack of polarization mode dispersion and ease of fabrication. 相似文献
16.
We analyze the properties of magneto-optical defect states in two-dimensional photonic crystals. With out-of-plane magnetization, the magneto-optical coupling splits doubly-degenerate TE states into two counter-rotating modes at different frequencies. The strength of magneto-optical coupling strongly depends on the spatial overlap of the cavity domain structures and the cross product of the modal fields. The transport property of the resultant nonreciprocal states is demonstrated in a junction circulator structure with a magneto-optical cavity coupled to three waveguides. By a proper matching of the magneto-optical frequency splitting with the cavity decay rate into the waveguide, ideal three-port circulator characteristics with complete isolation and transmission can be achieved, with an operational bandwidth proportional to the magneto-optical constant. The proposed optical circulator in a bismuth-iron-garnet/air photonic crystal is demonstrated with finite-difference time-domain calculations and is compared to an alternative implementation of silicon/air crystal infiltrated with a single bismuth-iron-garnet domain. 相似文献
17.
18.
R. S. Chen D. X. Wang Edward K. N. Yung 《International Journal of Infrared and Millimeter Waves》2004,25(4):633-647
The generalized minimal residual (GMRES) iterative method is applied to solve such sparse large non-symmetric system of linear equations resulting from the use of edge-based finite element method. In order to speed up the convergence of GMRES, the symmetric successive overrelaxation (SSOR) preconditioning scheme is applied for the analysis of millimeter wave ferrite circulator. Consequently, this preconditioned GMRES (PGMRES) approach can reach convergence 19 times faster than GMRES. The isolation and insertion losses of millimeter wave waveguide circulator are compared with those obtained from literature. 相似文献
19.
Z. B. Ye Wanchun Tang S. S. Li 《International Journal of Infrared and Millimeter Waves》2006,27(8):1109-1117
In this paper, the modified matrix pencil (MMP) method is used in the finite difference time domain (FDTD) method to eliminate
the late time instability of time domain responses when analyzing the novel microstrip circulator with a magnetized ferrite
sphere. The frequency dependent scattering parameters: reflection, isolation and insertion parameters of the microstrip circulator
calculated over a wide band of frequencies with this hybrid method are compared with that obtained by direct FDTD method which
agree well with the experimental results. 相似文献