Design and Simulation of Passive Reflecting Surfaces for 5G Applications

Design and simulation of passive reflectors to be used in 5G applications are presented. An optimization environment is constructed based on genetic algorithms (GAs) and a full-wave solver to obtain compact reflectors that possess various reflection characteristics in accordance with given design specifications. In addition to their triangulated models for simulations, reflectors are represented by Bezier surfaces on the optimization side to reach smooth designs that are suitable for fabrication. A multigrid approach is further used to increase the effectiveness of the optimization trials via a systematic deformation of surfaces from coarse shaping to fine tuning. The results demonstrate the feasibility of achieving diverse reflection characteristics with relatively compact reflectors, as well as the effectiveness of the proposed optimization strategy

Accurate and Efficient Broadband Simulations of Three-Dimensional Closed Conductors Using a Combined Potential-Field Formulation

A novel formulation involving a combination of potential and field formulations is presented for stable analyses of closed conductors with various sizes and discretizations

Accurate and Efficient Solutions of Densely Discretized Closed Conductors Using a Combined Potential-Field Formulation

We present an accurate, efficient, and stable formulation for rigorous analyses of electromagnetic problems involving closed conductors. The formulation, namely the combined potential-field formulation (CPFF), is constructed from the conventional potential integral equations and the magnetic-field integral equation, together with an additional integral equation using the boundary condition for the normal component of the magnetic vector potential. Being both low-frequency-stable and resonance-free, CPFF is a broadband formulation, which enables accurate and efficient solutions of objects with diverse dimensions and discretization sizes

Design and analysis of nano-optical networks consisting of nanowires and optimized couplers

We present computational design and investigation of nano-optical systems involving nanowires and well-designed nano-couplers to effectively transmit electromagnetic power in nanometer scales. Different nano-couplers, which consist of optimal arrangements of nano-cubes, are carefully designed by considering various scenarios, e.g., nanowire lines with sharp corners and junctions. An efficient combination of genetic algorithms and the multilevel fast multipole algorithm is used to find suitable configurations of nano-cubes that provide desired electromagnetic responses. Combinations of multiple nano-couplers and nanowires allow us to build larger nano-optical systems with different shapes, inputs, and outputs. Initial results presented in this paper demonstrate the feasibility of complex networks based on nanowires and nano-couplers

Shape Optimizations of Metallic Sheets Using a Multigrid Approach

We present a novel multigrid approach for the shape optimizations of corrugated metallic sheets by using genetic algorithms (GAs) and the multilevel fast multipole algorithm (MLFMA). The overall mechanism is obtained by an efficient integration of GAs and MLFMA, while the optimizations are improved by applying multiple grids at different layers. We show that the multigrid approach provides more effective optimizations than the conventional no-grid optimizations that employ the discretization nodes directly. The multigrid optimizations become useful especially as the problem size grows and no-grid optimizations demonstrate poor performances

Combined Potential-Field Surface Formulations for Resonance-Free and Low-Frequency-Stable Analyses of Three-Dimensional Closed Conductors

© 2021 EurAAP.We present combined formulations involving the recently developed potential integral equations (PIEs) together with field formulations, particularly the magnetic-field integral equation (MFIE), for accurate, efficient, and stable analyses of three-dimensional closed conductors. This kind of combinations are required since PIEs suffer from internal resonances and are prone to numerical issues for relatively large conductors. By combining PIEs with MFIE, we obtain low-frequency-stable implementations that can be employed at both low and high frequencies without any resonance artifacts in numerical results

Design and optimization of nano-optical couplers for controlling transmission between electrically isolated nanowires

© 2019 IEEE.We present design, optimization, and simulation of effective nano-optical couplers to control power transmission in nanowire networks. The couplers consist of careful arrangements of nanoparticles that are designed in an optimization environment based on genetic algorithms and a full-wave solver. The nanowire segments are electrically isolated from each other, leading to more reconfigurable and adaptable systems. We show that, even in the absence of direct contacts between nanowires, high-performance power transmission can be achieved with the designed compact couplers, while their flexibility allows for the construction of more complex systems