scholarly journals Reverse Design of On-Chip Terahertz Demultiplexers

Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1093
Author(s):  
Guofeng Zhu ◽  
Feng Huang ◽  
Zhenrong Dai ◽  
Xuewei Ju ◽  
Shuncong Zhong ◽  
...  
Keyword(s):  
Finite Difference Time Domain ◽  
Design Method ◽  
Research Field ◽  
Fdtd Simulation ◽  
Terahertz Waves ◽  
Bandwidth Optimization ◽  
Simulation Results ◽  
On Chip ◽  
Adjacent Channels ◽  
Difference Time

The reverse design method (RDM) is a frontier direction in the optical research field. In this work, RDM is applied to the design of terahertz demultiplexers, including two-port and three-port terahertz demultiplexers, with areas of 3 mm × 3 mm and 5 mm × 5 mm, respectively. The Finite-Difference Time-Domain (FDTD) simulation results show that the terahertz waves at frequencies of 0.5 THz and 0.417 THz can be well separated by the two-port demultiplexer, and the transmittances of the two outputs reach as high as 0.75 after bandwidth optimization. Meanwhile, the three-port terahertz demultiplexer can have terahertz waves separated from three Ports, and the crosstalk between adjacent channels is less than −18 dB.

Non-quasi-static Effects Simulation of Microwave Circuits based on Physical Model of Semiconductor Devices

2020 ◽  
Vol 35 (9) ◽  
pp. 992-998
Author(s):  
Ke Xu ◽  
Xing Chen ◽  
Qiang Chen
Keyword(s):  
Physical Model ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Circuit Simulation ◽  
Semiconductor Devices ◽  
Simulation Method ◽  
Fdtd Simulation ◽  
Lumped Element ◽  
Simulation Results ◽  
Difference Time

This work explores analyzing the non-quasistatic effects of a microwave circuit by employing a physical model-based field-circuit co-simulation method. Specifically, it uses the semiconductor physical model to characterize the semiconductor devices, and simulates the lumped circuit by cooperating semiconductor physical equations into Kirchhoff’s circuit equations. Then the lumped circuit simulation is hybridized with the finite-difference time-domain (FDTD) simulation by interfacing EM (electromagnetic) field quantities with lumped-element quantities at each timestep. Taken a microwave limiter circuit as an example, the simulation results agree well with the measured results, which prove that this method can characterize non-quasi-static effects well. As a comparison, the equivalent circuit modelbased co-simulation cannot characterize the non-quasistatic effects accurately.

scholarly journals Metasurface of Combined Semicircular Rings with Orthogonal Slit Pairs for Generation of Dual Vector Beams

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1718
Author(s):  
Qian Kong ◽  
Manna Gu ◽  
Xiangyu Zeng ◽  
Rui Sun ◽  
Yuqin Zhang ◽  
...  
Keyword(s):  
Time Domain ◽  
Finite Difference Time Domain ◽  
Polarized Light ◽  
Orientation Angle ◽  
Fdtd Simulation ◽  
Dual Vector ◽  
Vector Beams ◽  
Linearly Polarized ◽  
Potential Applications ◽  
Difference Time

Manipulation of multichannel vector beams (VBs) with metasurfaces is an important topic and holds potential applications in information technology. In this paper, we propose a novel metasurface for the generation of dual VBs, which is composed of orthogonal slit pairs arranged on multiple groups of combined semicircular rings (CSRs). A group of CSRs include a right-shifted set and a left-shifted set of semicircular rings, and each set of semicircular rings has two halves of circles with different radii, sharing the same shifted center. Under the illumination of linearly polarized light, the two shifted sets of semicircular rings generate the two VBs at the shifted center positions on the observation plane. The slit units of each set are designed with independent rotation order and initial orientation angle. By adjusting the linear polarization of illumination, both two VBs with their orders and polarization states are independently controlled simultaneously. The principle and design are demonstrated by the finite-difference time domain (FDTD) simulation. The work is of significance for miniatured devices of VB generators and for related applications.

scholarly journals Size Determination of Polystyrene Sub-Microspheres Using Transmission Spectroscopy

2020 ◽  
Vol 10 (15) ◽  
pp. 5232
Author(s):  
Tien Van Nguyen ◽  
Linh The Pham ◽  
Khuyen Xuan Bui ◽  
Lien Ha Thi Nghiem ◽  
Nghia Trong Nguyen ◽  
...  
Keyword(s):  
Time Domain ◽  
Finite Difference Time Domain ◽  
Fdtd Simulation ◽  
Transmission Spectra ◽  
Experimental Transmission ◽  
Straightforward Method ◽  
Quartz Substrates ◽  
Difference Time ◽  
Good Agreement

Nano/micro polystyrene (PS) beads have found many applications in different fields spanning from drug delivery, bio-diagnostics, and hybrid plasmonics to advanced photonics. The sizes of the PS beads are an important parameter, especially in plasmonic and photonic experiments. In this work, we demonstrate a quick and straightforward method to estimate the diameters of sub-microspheres (0.2 μm to 0.8 μm) using the transmission spectra of a close-packed monolayer of polystyrene beads on glass or quartz substrates. Experimental transmission spectra of the PS monolayers were verified against finite-difference time-domain (FDTD) simulation and showed good agreement. The effects of the substrates on the transmission spectra and, hence, the accuracy of the method were also studied by simulation, which showed that common transparent substrates only cause minor deviation of the PS bead sizes calculated by the proposed method.

Quantifying Sub-gridding Errors in Standard and Hybrid Higher Order 2D FDTD Simulations

2021 ◽  
Vol 35 (11) ◽  
pp. 1428-1429
Author(s):  
Madison Le ◽  
Mohammed Hadi ◽  
Atef Elsherbeni
Keyword(s):  
Finite Difference ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Contrast Ratio ◽  
Higher Order ◽  
Fdtd Simulation ◽  
Fdtd Simulations ◽  
2D Fdtd ◽  
Difference Time

Sub-gridding errors for a 2D Finite-Difference Time-Domain (FDTD) simulation are compared for both the standard FDTD and Hybrid higher order FDTD cases. Subgridding contrast ratios of 1:3, 1:9, 1:15, and 1:27 are considered and analyzed. A correlation is seen between the increase of contrast ratio with the increase of sub-gridding errors for both standard and hybrid cases. However, a trend of errors reduction when using hybrid formulations over standard formulations is apparent for each contrast ratio.

Field Distribution Adjacent to Apertures Located on Infinite Plates

2014 ◽  
Vol 602-605 ◽  
pp. 335-338
Author(s):  
Run Xiong ◽  
Bin Chen ◽  
Zheng Jun Wang
Keyword(s):  
Electromagnetic Field ◽  
Field Distribution ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Infinite Plate ◽  
Fdtd Simulation ◽  
Electromagnetic Field Distribution ◽  
Coupling Principle ◽  
Difference Time ◽  
Electromagnetic Field Component

In this paper, electromagnetic field distribution adjacent to the aperture is analyzed to help deducing the coupling principle of apertures. The aperture is located on an infinite plate to avoid the effect of other structures. Taking advantage of high-resolution standard finite-difference time-domain (FDTD) simulation, it is possible to observe the electromagnetic field distribution adjacent to the aperture. From analyses, it can be seen that the electromagnetic field component is dramatically varied adjacent to the aperture, and conclusions drawn here is helpful to deduce the coupling principle of apertures.

Numerical Simulation and Experimental Validation of RF Drying

1996 ◽  
Vol 430 ◽  
Author(s):  
S. Bringhurst ◽  
M. J White ◽  
M. F. Iskander
Keyword(s):  
Microwave Sintering ◽  
Fdtd Method ◽  
Fdtd Simulation ◽  
Ceramic Ware ◽  
Rf Heating ◽  
Simulation Results ◽  
Effective Use ◽  
Difference Time ◽  
Experimental Effort ◽  
Fiber Optic Temperature

AbstractThe Finite-Difference Time-Domain (FDTD) method has been used by our group to simulate a wide variety of Radio Frequency (RF) and induction-drying processes and realistic, microwave-sintering experiments. Many results were presented and some guidelines towards the effective use of the microwave and RF heating technologies of ceramic ware were developed.In this paper we describe an experimental effort which was used to validate the FDTD simulation results. Specifically an experimental RF dryer, Thermax Model No. T3GB operating at 25 MHz, was used to dry ceramic ware of various materials, sizes, and shapes and the temperature distribution pattern was monitored using six fiber-optic temperature probes. The measured heating patterns were then compared with the FDTD simulation results. Many of the guidelines developed using the numerical simulations were confirmed experimentally.Results from various comparisons between simulation and experimental data will be presented. Additional results from the simulation efforts illustrating possible procedures for improving the efficiency and the uniformity of RF drying will also be described

Sign in / Sign up

Export Citation Format

Share Document