In this paper, the reconstruction problem of inaccessible objects buried into a three-part space with locally rough interfaces is solved by Distorted Born Iterative Method (DBIM). DBIM requires the calculation of the background electric field and Green’s function in every iteration step via the solution of the direct scattering problem. Here, they are calculated numerically by using the buried object approach (BOA) which is very useful in the solutions of the problems including stratified media with locally rough interfaces. Various numerical applications have been performed to demonstrate the applicability and efficiency of the method. The method was found to be very successful in reconstructing moderate contrast objects when they were buried in the middle space. In this case, the method works effectively even if the buried objects and interface roughnesses have complex geometric structures. Moreover, the multiplicity of buried objects has no negative effect on the reconstruction results. Nevertheless, the results of reconstruction deteriorate when objects are buried in the bottom space. However, the accuracies of them are still on an acceptable level in this situation.
{"title":"RECONSTRUCTION OF TWO-DIMENSIONAL OBJECTS BURIED INTO THREE-PART SPACE WITH LOCALLY ROUGH INTERFACES VIA DISTORTED BORN ITERATIVE METHOD","authors":"Y. Altuncu, Tulun Durukan, R. Akdogan","doi":"10.2528/pier19072203","DOIUrl":"https://doi.org/10.2528/pier19072203","url":null,"abstract":"In this paper, the reconstruction problem of inaccessible objects buried into a three-part space with locally rough interfaces is solved by Distorted Born Iterative Method (DBIM). DBIM requires the calculation of the background electric field and Green’s function in every iteration step via the solution of the direct scattering problem. Here, they are calculated numerically by using the buried object approach (BOA) which is very useful in the solutions of the problems including stratified media with locally rough interfaces. Various numerical applications have been performed to demonstrate the applicability and efficiency of the method. The method was found to be very successful in reconstructing moderate contrast objects when they were buried in the middle space. In this case, the method works effectively even if the buried objects and interface roughnesses have complex geometric structures. Moreover, the multiplicity of buried objects has no negative effect on the reconstruction results. Nevertheless, the results of reconstruction deteriorate when objects are buried in the bottom space. However, the accuracies of them are still on an acceptable level in this situation.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"46 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87844678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Kornprobst, R. A. Mauermayer, O. Neitz, J. Knapp, T. Eibert
Various formulations of the inverse equivalent surface-source problem and corresponding solution approaches are discussed and investigated. Starting from the radiation integrals of electric and magnetic surface current densities, the probe-corrected inverse equivalent source formulation is set up together with different forms of side constraints such as the zero-field or Love condition. The linear systems of equations resulting from the discretized forms of these equations are solved by the normal residual (NR) and normal error (NE) systems of equations. As expected and as demonstrated by the solution of a variety of inverse equivalent surface-source problems, related to synthetic as well as realistic antenna near-field measurement data, it is found that the iterative solution of the NE equations allows for a better control of the solution error and leads in general to a slightly faster convergence. Moreover, the results show that the incorporation of the zero-field condition into the solution process is in general not beneficial, which is also supported by the structure of the NE systems of equations. If desired, Love surface current densities, or just fields in general, can more easily be computed in a post-processing step. The accuracy of the obtained near-fields and far-fields depends more on the stopping criterion of the inverse source solver than on the particular choice of the equivalent surface-source representation, where the zero-field condition may influence the stopping criterion in a rather unpredictable way.
{"title":"ON THE SOLUTION OF INVERSE EQUIVALENT SURFACE-SOURCE PROBLEMS","authors":"J. Kornprobst, R. A. Mauermayer, O. Neitz, J. Knapp, T. Eibert","doi":"10.2528/PIER19050904","DOIUrl":"https://doi.org/10.2528/PIER19050904","url":null,"abstract":"Various formulations of the inverse equivalent surface-source problem and corresponding solution approaches are discussed and investigated. Starting from the radiation integrals of electric and magnetic surface current densities, the probe-corrected inverse equivalent source formulation is set up together with different forms of side constraints such as the zero-field or Love condition. The linear systems of equations resulting from the discretized forms of these equations are solved by the normal residual (NR) and normal error (NE) systems of equations. As expected and as demonstrated by the solution of a variety of inverse equivalent surface-source problems, related to synthetic as well as realistic antenna near-field measurement data, it is found that the iterative solution of the NE equations allows for a better control of the solution error and leads in general to a slightly faster convergence. Moreover, the results show that the incorporation of the zero-field condition into the solution process is in general not beneficial, which is also supported by the structure of the NE systems of equations. If desired, Love surface current densities, or just fields in general, can more easily be computed in a post-processing step. The accuracy of the obtained near-fields and far-fields depends more on the stopping criterion of the inverse source solver than on the particular choice of the equivalent surface-source representation, where the zero-field condition may influence the stopping criterion in a rather unpredictable way.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"223 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85924544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Binhao Wang, Qiangsheng Huang, Kaixuan Chen, Jianhao Zhang, G. Kurczveil, D. Liang, S. Palermo, M. Tan, R. Beausoleil, Sailing He
Datacenters become an important part of technical infrastructure. The Datacom traffic grows exponentially to satisfy the demands in IT services, storage, communications, and networking to the growing number of networked devices and users. High bandwidth and energy efficient optical interconnects are critical to improve overall productivity and efficiency in data centers. Mega-data centers are expected to address the power consumption and the cost in which optical interconnects contribute quite a large part. Silicon photonics is a promising platform to offer savings in power and potential increase in bandwidth for Datacom. Several modulation techniques are developed in silicon photonics to reduce the optical mode volume or enhance the light matter effect to further improve the modulation efficiency. Many other materials such as III-V and LiNbO3 are integrated on silicon photonics to maximize the optical link performance. This paper reviews several modulation techniques for Datacom, from vertical-cavity surface-emitting laser (VCSEL) direct modulation to silicon photonics modulators then to hybrid silicon modulators.
{"title":"MODULATION ON SILICON FOR DATACOM: PAST, PRESENT, AND FUTURE (INVITED REVIEW)","authors":"Binhao Wang, Qiangsheng Huang, Kaixuan Chen, Jianhao Zhang, G. Kurczveil, D. Liang, S. Palermo, M. Tan, R. Beausoleil, Sailing He","doi":"10.2528/pier19102405","DOIUrl":"https://doi.org/10.2528/pier19102405","url":null,"abstract":"Datacenters become an important part of technical infrastructure. The Datacom traffic grows exponentially to satisfy the demands in IT services, storage, communications, and networking to the growing number of networked devices and users. High bandwidth and energy efficient optical interconnects are critical to improve overall productivity and efficiency in data centers. Mega-data centers are expected to address the power consumption and the cost in which optical interconnects contribute quite a large part. Silicon photonics is a promising platform to offer savings in power and potential increase in bandwidth for Datacom. Several modulation techniques are developed in silicon photonics to reduce the optical mode volume or enhance the light matter effect to further improve the modulation efficiency. Many other materials such as III-V and LiNbO3 are integrated on silicon photonics to maximize the optical link performance. This paper reviews several modulation techniques for Datacom, from vertical-cavity surface-emitting laser (VCSEL) direct modulation to silicon photonics modulators then to hybrid silicon modulators.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"33 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84998129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Harley, M. U. Saleh, S. Kingston, M. Scarpulla, C. Furse
This paper studies a computationally efficient algebraic graph theory engine for simulating time-domain one-dimensional waves in a multi-segment transmission line, such as for reflectometry applications. Efficient simulation of time-domain signals in multi-segment transmission lines is challenging because the number of propagation paths (and therefore the number of operations) increases exponentially with each new interface. We address this challenge through the use of a frequencydomain, algebraic graphical model of wave propagation, which is then converted to the time domain via the Fourier transform. We use this model to achieve an exact, stable, and computationally efficient (O(NQ), where N is the number of segments and Q is the bandwidth) approach for studying onedimensional wave propagation. Our approach requires the reflection and transmission coefficients for each interface and each segment’s complex propagation constant. We compare our simulation results with known analytical solutions.
{"title":"FAST TRANSIENT SIMULATIONS FOR MULTI-SEGMENT TRANSMISSION LINES WITH A GRAPHICAL MODEL","authors":"J. Harley, M. U. Saleh, S. Kingston, M. Scarpulla, C. Furse","doi":"10.2528/PIER19042105","DOIUrl":"https://doi.org/10.2528/PIER19042105","url":null,"abstract":"This paper studies a computationally efficient algebraic graph theory engine for simulating time-domain one-dimensional waves in a multi-segment transmission line, such as for reflectometry applications. Efficient simulation of time-domain signals in multi-segment transmission lines is challenging because the number of propagation paths (and therefore the number of operations) increases exponentially with each new interface. We address this challenge through the use of a frequencydomain, algebraic graphical model of wave propagation, which is then converted to the time domain via the Fourier transform. We use this model to achieve an exact, stable, and computationally efficient (O(NQ), where N is the number of segments and Q is the bandwidth) approach for studying onedimensional wave propagation. Our approach requires the reflection and transmission coefficients for each interface and each segment’s complex propagation constant. We compare our simulation results with known analytical solutions.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78141629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We consider the Global Navigation Satellite System Reflectometry (GNSS-R) for land applications. A distinct feature of land is that the topography has multiple elevations. The rms of elevations is in meters causing random phases between different elevations, which affect the coherent wave that has definite phase and the Fresnel zone effects as shown previously by a Kirchhoff numerical simulator (KA simulator). In this paper, we develop a physical patch model that is computationally efficient. The entire area within the footprint is divided into patches. Each patch is small enough to satisfy the plane wave incidence and is large enough to ignore mutual wave interactions between patches. The bistatic scattering cross section of each patch for the coherent and incoherent field is computed. The bistatic cross section of plane wave incidence is obtained from lookup tables (LUTs) of the numerical 3D solution of Maxwell equations (NMM3D). The SWC represents the summation of weighted coherent fields over patches. The SWICI represents the summation of weighted incoherent intensities over patches. The formula of the received power is the sum of powers from the SWC and SWICI (the SWC/SWICI formula). The weighting factor of each patch is based on the geometry, spherical waves, and the considerations of field amplitudes and phase variations. We also present an alternative formula, the “correlation” formula, using the summation of power from each physical area and correlations of SWCs from areas. The SWC/SWICI formula and the “correlation” formula are shown analytically to be the same. Results are compared with the KA simulator and two common models (the coherent model and the incoherent model). Results of the patch model are consistent with the KA simulator. For the simulation cases, the results fall between the coherent model and the incoherent model. The patch model is much more computationally efficient than the KA simulator and the results are more accurate. In examples of this paper, the patch model results are independent of patch size as long as the patch size smaller than 50 m and much larger than the wavelength of GNSS-R frequency.
{"title":"A PHYSICAL PATCH MODEL FOR GNSS-R LAND APPLICATIONS","authors":"Jiyue Zhu, L. Tsang, Haokui Xu","doi":"10.2528/PIER19031003","DOIUrl":"https://doi.org/10.2528/PIER19031003","url":null,"abstract":"We consider the Global Navigation Satellite System Reflectometry (GNSS-R) for land applications. A distinct feature of land is that the topography has multiple elevations. The rms of elevations is in meters causing random phases between different elevations, which affect the coherent wave that has definite phase and the Fresnel zone effects as shown previously by a Kirchhoff numerical simulator (KA simulator). In this paper, we develop a physical patch model that is computationally efficient. The entire area within the footprint is divided into patches. Each patch is small enough to satisfy the plane wave incidence and is large enough to ignore mutual wave interactions between patches. The bistatic scattering cross section of each patch for the coherent and incoherent field is computed. The bistatic cross section of plane wave incidence is obtained from lookup tables (LUTs) of the numerical 3D solution of Maxwell equations (NMM3D). The SWC represents the summation of weighted coherent fields over patches. The SWICI represents the summation of weighted incoherent intensities over patches. The formula of the received power is the sum of powers from the SWC and SWICI (the SWC/SWICI formula). The weighting factor of each patch is based on the geometry, spherical waves, and the considerations of field amplitudes and phase variations. We also present an alternative formula, the “correlation” formula, using the summation of power from each physical area and correlations of SWCs from areas. The SWC/SWICI formula and the “correlation” formula are shown analytically to be the same. Results are compared with the KA simulator and two common models (the coherent model and the incoherent model). Results of the patch model are consistent with the KA simulator. For the simulation cases, the results fall between the coherent model and the incoherent model. The patch model is much more computationally efficient than the KA simulator and the results are more accurate. In examples of this paper, the patch model results are independent of patch size as long as the patch size smaller than 50 m and much larger than the wavelength of GNSS-R frequency.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87673752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Liangliang Liu, L. Ran, Huadong Guo, Xinlei Chen, Zhuo Li
Building of compact plasmonic integrated circuits based on domino spoof plasmons (DSPs) is an important requirement and still a challenge. In this work, we report the first demonstration of two kinds of channel domino plasmonic circuitries, which consist of an easy-to-manufacture periodic chain of metallic box-shaped elements inside two finite metallic plates. We reveal that only the channel DSPs itself rather than the hybrid TE10 and DSPs modes is supported in the part of the channel domino plasmonic waveguide with or without the metallic vias on both sides. Two channel domino plasmonic filters based on the efficient transition structures are designed, and the simulated Sparameters and near electric field distributions show excellent transmission performance in broadband. Utilizing the lateral insensitive property of these two channel DSPs, two kinds of broadband plasmonic power dividers/combiners are firstly implemented. Excellent transmission performance validates our optimizations and indicates that the proposed scheme can be easily extended to other bands. This work provides a new route for construction of deep-subwavelength DSP devices in application of high integration of microwave and terahertz circuits.
{"title":"BROADBAND PLASMONIC CIRCUITRY ENABLED BY CHANNEL DOMINO SPOOF PLASMONS","authors":"Liangliang Liu, L. Ran, Huadong Guo, Xinlei Chen, Zhuo Li","doi":"10.2528/pier18120502","DOIUrl":"https://doi.org/10.2528/pier18120502","url":null,"abstract":"Building of compact plasmonic integrated circuits based on domino spoof plasmons (DSPs) is an important requirement and still a challenge. In this work, we report the first demonstration of two kinds of channel domino plasmonic circuitries, which consist of an easy-to-manufacture periodic chain of metallic box-shaped elements inside two finite metallic plates. We reveal that only the channel DSPs itself rather than the hybrid TE10 and DSPs modes is supported in the part of the channel domino plasmonic waveguide with or without the metallic vias on both sides. Two channel domino plasmonic filters based on the efficient transition structures are designed, and the simulated Sparameters and near electric field distributions show excellent transmission performance in broadband. Utilizing the lateral insensitive property of these two channel DSPs, two kinds of broadband plasmonic power dividers/combiners are firstly implemented. Excellent transmission performance validates our optimizations and indicates that the proposed scheme can be easily extended to other bands. This work provides a new route for construction of deep-subwavelength DSP devices in application of high integration of microwave and terahertz circuits.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81061868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, the Compressive Sampling Matching Pursuit Algorithm (CoSaMP) is applied to microwave reconstruction of a 2-dimensional non-sparse object. First, an adaptive discretization method, DistMesh method, is applied to discretize the image domain based on the region of interest. The dual-mesh method is able to provide denser and smaller discretized cells in more important areas of the object and larger cells in other areas, thereby providing more details in the interest domain and keeping the computational burden at a reasonable level. Another benefit of using the dual-mesh method is that it automatically generates size functions and adapts to the curvature and the feature size of the geometry. In addition, the size of each cell changes gradually. Next, the inverse scattering problem is solved in frame of Distorted Born Iterative Method (DBIM). During each iteration of DBIM, the near field scattering problem is modeled as a set of linear equations. Furthermore, a compressive sensing (CS) method called the Compressive Sampling Matching Pursuit Algorithm is applied to solve the nonlinear inverse problem. During this process, two innovative steps are applied. First, for the reconstruction of the non-sparse object, the signal input to our algorithm is processed via a wavelet transformation to obtain sparsity. Second, as the dual-mesh method discretizes more important cells in smaller sizes, these cells have high potential to be filtered by the threshold of CoSaMP. As a result, a regularization matrix is introduced to reduce the effect of size. Finally, we present numerical experiment results based on our dual-mesh method combined with the regularized CoSaMP algorithm.
{"title":"A DUAL-MESH MICROWAVE RECONSTRUCTION METHOD BASED ON COMPRESSIVE SAMPLING MATCHING PURSUIT ALGORITHM","authors":"Huiyuan Zhou, R. Narayanan","doi":"10.2528/pier19090203","DOIUrl":"https://doi.org/10.2528/pier19090203","url":null,"abstract":"In this paper, the Compressive Sampling Matching Pursuit Algorithm (CoSaMP) is applied to microwave reconstruction of a 2-dimensional non-sparse object. First, an adaptive discretization method, DistMesh method, is applied to discretize the image domain based on the region of interest. The dual-mesh method is able to provide denser and smaller discretized cells in more important areas of the object and larger cells in other areas, thereby providing more details in the interest domain and keeping the computational burden at a reasonable level. Another benefit of using the dual-mesh method is that it automatically generates size functions and adapts to the curvature and the feature size of the geometry. In addition, the size of each cell changes gradually. Next, the inverse scattering problem is solved in frame of Distorted Born Iterative Method (DBIM). During each iteration of DBIM, the near field scattering problem is modeled as a set of linear equations. Furthermore, a compressive sensing (CS) method called the Compressive Sampling Matching Pursuit Algorithm is applied to solve the nonlinear inverse problem. During this process, two innovative steps are applied. First, for the reconstruction of the non-sparse object, the signal input to our algorithm is processed via a wavelet transformation to obtain sparsity. Second, as the dual-mesh method discretizes more important cells in smaller sizes, these cells have high potential to be filtered by the threshold of CoSaMP. As a result, a regularization matrix is introduced to reduce the effect of size. Finally, we present numerical experiment results based on our dual-mesh method combined with the regularized CoSaMP algorithm.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88768688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We propose a camouflage device that can greatly reduce scattering in the microwave frequency using only uniform copper plates with no internal structuring (no metamaterials). The camouflage device is designed by optical surface transformation (OST), which is derived from transformation optics but much simpler than transformation optics. The key of our design is to choose suitable arrangement and lengths of these copper plates that satisfy Fabry-Perot condition. The proposed camouflage device can work when the detecting wave comes from a wide-angle range (not only works for some discrete angles). The proposed method will give a new and simple way to design and realize camouflage device.
{"title":"A CAMOUFLAGE DEVICE WITHOUT METAMATERIALS","authors":"F. Sun, Yijie Zhang, Julian Evans, Sailing He","doi":"10.2528/pier19080803","DOIUrl":"https://doi.org/10.2528/pier19080803","url":null,"abstract":"We propose a camouflage device that can greatly reduce scattering in the microwave frequency using only uniform copper plates with no internal structuring (no metamaterials). The camouflage device is designed by optical surface transformation (OST), which is derived from transformation optics but much simpler than transformation optics. The key of our design is to choose suitable arrangement and lengths of these copper plates that satisfy Fabry-Perot condition. The proposed camouflage device can work when the detecting wave comes from a wide-angle range (not only works for some discrete angles). The proposed method will give a new and simple way to design and realize camouflage device.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"66 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84075084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We propose a planar chiral metamaterial (PCMM), which can function as a triple-band polarization angle independent 90◦ polarization rotator. The unit cell of the PCMM is composed of bi-layered mutual twisted Fermat’s spiral structure (FSS) resonators with four-fold rotation symmetry. The simulated and measured results show that the PCMM can work in triple-band and convert a linearly polarized (y-/x-polarized) wave to its cross-polarization (x-/y-polarized) or experience a near 90◦ polarization rotation with a polarization conversion ratio of over 90%. The electric field and surface current distributions of the unit-cell structure are analyzed to study its physics mechanism. Compared with previous CMM-based rotator, our design has more operation frequencies in a single PCMM structure, a relative thinner thickness, and higher Q-factor. Good performances of the PCMM suggest promising applications in the polarization rotator or convertor that need to be integrated with other compact devices.
{"title":"TRIPLE-BAND POLARIZATION ANGLE INDEPENDENT 90° POLARIZATION ROTATOR BASED ON FERMAT'S SPIRAL STRUCTURE PLANAR CHIRAL METAMATERIAL","authors":"Yongzhi Cheng, Wangyang Li, X. Mao","doi":"10.2528/PIER18112603","DOIUrl":"https://doi.org/10.2528/PIER18112603","url":null,"abstract":"We propose a planar chiral metamaterial (PCMM), which can function as a triple-band polarization angle independent 90◦ polarization rotator. The unit cell of the PCMM is composed of bi-layered mutual twisted Fermat’s spiral structure (FSS) resonators with four-fold rotation symmetry. The simulated and measured results show that the PCMM can work in triple-band and convert a linearly polarized (y-/x-polarized) wave to its cross-polarization (x-/y-polarized) or experience a near 90◦ polarization rotation with a polarization conversion ratio of over 90%. The electric field and surface current distributions of the unit-cell structure are analyzed to study its physics mechanism. Compared with previous CMM-based rotator, our design has more operation frequencies in a single PCMM structure, a relative thinner thickness, and higher Q-factor. Good performances of the PCMM suggest promising applications in the polarization rotator or convertor that need to be integrated with other compact devices.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79276209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A novel and systematic method is developed to evaluate periodic Green’s functions on empty lattices through extractions of an imaginary wavenumber component of the lattice Green’s function and its associated derivatives. We consider cases of volumetric periodicity where the dimensionality of the periodicity has the same dimensionality as the physical problem. This includes one-dimensional (1D) problem with 1D periodicity, two-dimensional (2D) problem with 2D periodicity, and three-dimensional (3D) problem with 3D periodicity, respectively. The remainder of the Green’s function is put in spectral series with high-order power-law convergence rates, while the extracted imaginary wavenumber parts are put in spatial series with super-fast and close-to exponential convergence rate. The formulation is free of transcendental functions and thus simple in implementation. It is especially efficient for broadband evaluations of the Green’s function as the spatial series are defined on fixed wavenumbers that take small CPU to compute, and the spectral series have simple and separable wavenumber dependences. Keeping only a few terms in both the spatial and spectral series, results of the lattice Green’s function are in good agreement with benchmark solutions in 1D, 2D, and 3D, respectively, demonstrating the high accuracy and computational efficiency of the proposed method. The proposed method can be readily generalized to deal with Green’s functions including arbitrary periodic scatterers.
{"title":"EFFICIENT BROADBAND EVALUATIONS OF LATTICE GREEN'S FUNCTIONS VIA IMAGINARY WAVENUMBER COMPONENTS EXTRACTIONS","authors":"Shurun Tan, L. Tsang","doi":"10.2528/PIER18102001","DOIUrl":"https://doi.org/10.2528/PIER18102001","url":null,"abstract":"A novel and systematic method is developed to evaluate periodic Green’s functions on empty lattices through extractions of an imaginary wavenumber component of the lattice Green’s function and its associated derivatives. We consider cases of volumetric periodicity where the dimensionality of the periodicity has the same dimensionality as the physical problem. This includes one-dimensional (1D) problem with 1D periodicity, two-dimensional (2D) problem with 2D periodicity, and three-dimensional (3D) problem with 3D periodicity, respectively. The remainder of the Green’s function is put in spectral series with high-order power-law convergence rates, while the extracted imaginary wavenumber parts are put in spatial series with super-fast and close-to exponential convergence rate. The formulation is free of transcendental functions and thus simple in implementation. It is especially efficient for broadband evaluations of the Green’s function as the spatial series are defined on fixed wavenumbers that take small CPU to compute, and the spectral series have simple and separable wavenumber dependences. Keeping only a few terms in both the spatial and spectral series, results of the lattice Green’s function are in good agreement with benchmark solutions in 1D, 2D, and 3D, respectively, demonstrating the high accuracy and computational efficiency of the proposed method. The proposed method can be readily generalized to deal with Green’s functions including arbitrary periodic scatterers.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"60 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74577450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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