Microwave characteristic simulation research for a kind of novel electromagnetic structure

A kind of novel electromagnetic structure of Cassini cross section is proposed and simulation is implemented with business microwave soft CST based on finite integral technique （FIT）. The electromagnetic field mode type of Cassini wave-guide belongs to TE, and the electromagnetic field intensity is stronger near the neck region than at other areas. For Cassini electromagnetic patches and lumped elements, the radar cross section （RCS） is smaller around 7 GHz with -30.85 dBsm, and the absorbing property is better around 13 GHz with 4.56 dBsm difference of RCS from comparing of pure medium. For novel radiation structure of Cassini cross-section patches, the electromagnetic field value is larger in the neck areas of two half patches. At last, the potential application and development of Cassini oval structure are put forward in the electromagnetic stealth technology and antennae design.

Single Wall Carbon Nanotubes (SWCNTs) as (i) Type in the Photovoltaic Cell of Nano-Dimensions

In this paper, a new modified approach to design the photovoltaic cell has been presented by adding Single Wall Carbon Nanotubes (SWCNTs) as type (i). The main issue is to increase the efficiency of the photovoltaic cell, on the other hand, to exploit a larger range of electromagnetic wave frequencies, specifically a range within terahertz (THz) frequency domain, using 3D EM computer simulation technology (CST). It is clear in the normal PV cell start working at frequency of 500 THz, while the frequency at which the PV cell with SWCNTs operates is much less and it is close to zero, on the other hand, the PV cell with SWCNTs needs a larger cross-section area of 2800 nm2 to operate at frequency of 500 THz. This cell can be easily produced industrially, which means increases the efficiency of solar cell.

Novel Compact UWB Band Notch Antenna Design for Body-Centric Communications

This research analyzes and implements an innovative and tiny ultrawideband(UWB)antenna with band-notched features for body-centric communication.The shape of the designed antenna looks like a‘swan’with a slotted patch.Computer Simulation Technology(CST)is used to assess and investigate the performance of this antenna.With a band notch,this antenna can prevent interference from Wireless Local Area Network(WLAN)(5.15–5.825 GHz)and Worldwide Interoperability for Microwave Access(WiMAX)(5.25–5.85 GHz)systems.At first,the performance parameters like return loss response,gain,radiation patterns,and radiation efficiency of this UWB antenna are evaluated.After that,the human body effects on the antenna performance of the antenna are also examined to place the antenna at various distances away from 3-layers of phantom body model at different frequencies.All the on-body performance parameter results are compared and analyzed with free space performance parameter results.Lastly,by changing patch slot length and ground plane length,parametric studies were done for performance comparison.According to this research,it is noticed that the antenna is tiny and new.It shows good performance in body case as well.Hence,the antenna is very suitable for healthcare applications.

Optimal design on wideband directional coupler

Combining the modified Bethe small holes coupling theory with McDonald thickness theory and field averaging correction factor, it is accurate to design the weak coupling waveguide directional coupler. While the coupling is tight, the decrease of the field strength in the main waveguide caused by aperture should not be neglected. For a -6 dB directional coupler is described in this article, the theoretical value of coupling is good agree to the simulation value, by simulated and optimized with the professional software computer simulation technology （CST）. In the designed waveband, the error of coupling between theoretical value and simulating one is less than 0.25 dB. The error of coupling between simulation value and designed value is less than 0.5 dB. To improve the isolation, some spaces between two adjacent holes are turned from the traditional 1/4 centre guided wavelength. The performance of isolation has 5 dB improvement, and length of the coupling area is only 51.06 mm.

BP Neural Network Based on Microwave Method for Measuring the Moisture Content of Textile

The moisture content of yarn and fabric is an important factor in textiles industry.A novel microwave method used for material moisture content measurements is described in this paper.It can estimate the moisture content of the yarn roll with a standard deviation of 1.58% in the range of 0% to 90.00%.According to the actual size of the yarn,the yarn roll simulation model is established.The microwave attenuation variations arising from the changes in the conductivity and dielectric constant of the wet cone yarn from1.8 GHz to 5.0 GHz frequency are obtained by ultra-wideband antenna.The measured data are analyzed using the BP neural network.The result shows that it is a non-contact and online method to solve the moisture content of the yarn in the wide moisture content range.

Design and simulation of a wire position monitor for cryogenic systems in an ADS linac

This paper introduces the design and simulation of a Wire Position Monitor （WPM） used in the cryogenic system of an Accelerator Driven System （ADS）. The WPM is designed to monitor the contraction of cold masses during the cooling-down operation. In this paper, POISSON-2D electrostatic field software is used to calculate the best characteristic impedance for the WPM. Furthermore, the time domain signal of different end structures is theoretically analyzed and simulated. The coupling of electrodes and the influence of signal carrier size, which may influence the induced signal, are also discussed. Finally, the linearity of the induced voltage and the sensitivity of the WPM are analyzed. The time domain simulation results are consistent with the theoretical analysis. The influences of the coupling and carrier size are very small, and the linearity of the normalized voltage is good within r/2.