Commercial Electromagnetic Simulation Tool Research Articles

Dual band dielectric resonator antenna for high-speed applications

The antennas for wireless communication devices have undergone a tremendous expansion from the external monoband resonant antenna to the internal non-resonant multi-band antenna. In this paper, a dual-band dielectric resonator antenna for high-speed applications is proposed. Due to the complex edge-shaped boundary between the dielectric and air in a rectangular dielectric resonator antenna, a complex closed form of expression is difficult to achieve. To address this problem a half-cut cylinder is placed over the rectangular dielectric to achieve excellent radiation characteristics. This proposed antenna provides a wide dual-band response with fractional impedance bandwidth of 21.92% and 19.09%while operating from7.32 GHz to 9.12 GHz and 10.71 GHz to 12.95 GHz. It provides an average gain of 3dBi with high gain stability in the entire operating frequency band. The radiation efficiency is found to be 96% due to low ohmic and dielectric losses. The cross-polarization is around 20 dB lesser than the co-polarization. Its gain and directivity can further be enhanced by implementing serial and parallel array structures. This design uses HFSS 14.0 commercial electromagnetic simulation tools.

Electromagnetic shielding effectiveness of carbon fibre reinforced composites

This paper reports results on the shielding effectiveness parameter of laminated epoxy composites with carbon fibre reinforcements. Measurements of shielding effectiveness were carried out with a coaxial transmission line testing chamber according to ASTM 4935 standard and epoxy-matrix composites with continuous carbon-fibres were proven to be an excellent electromagnetic interference shielding material, where a composite slab made of 4 layers of prepregs provided more than 99.9% of electromagnetic attenuation. It was found that the reflection mechanism of the shielding material was mainly influenced by the fibre volume ratio, and that an increase in the number of layers of the composite resulted in higher shielding effectiveness due to a greater absorption mechanism. Calculations of the shielding effectiveness parameter of the material used were made by means of commercial electromagnetic simulation tools, having determined experimentally the overall resistivity of the composite. The findings presented in this work suggest that in presence of a greater number of interfaces at different impedance the separate modelling of matrix and fibres at mesoscopic scale must be taken into account.

Miniaturised antenna at a sub‐GHZ band for industrial remote controllers

This study presents the design and the fabrication of a miniaturised sub-GHz antenna for remote control applications. Miniaturisation techniques were examined to identify the most appropriate topology for sub-GHz band requirements. First, the design parameters of the antenna were determined, and then, a commercial electromagnetic simulation tool was used for the design and optimisation phases. Then, measurements of the fabricated antenna were undertaken. Parametric studies with several iterations were performed to achieve the best possible results. Second, the effects of the box in which the antenna could be placed were examined as most of such antennas are enclosed by plastic boxes. For this purpose, material properties of a typical industrial box available in the market were studied initially, and the most appropriate material of the box was used in simulations. Finally, a polyamide box with appropriate size was fabricated, and the designed antenna was placed inside the box and the measurements were conducted. The measurement results show that the designed antenna provides resonance at the targeted license-free band with adequate size for industrial remote controllers.

Electrical Modeling and Characterization of Silicon-Core Coaxial Through-Silicon Vias in 3-D Integration

Based on the extracted resistance, inductance, capacitance, and conductance parameters, this paper introduces the distributed transmission line model of silicon-core coaxial through-silicon vias (CTSVs), in which the vertical interconnect is made of a Cu-coated silicon pole. The proposed model is validated against a commercial electromagnetic simulation tool, showing it is highly accurate up to 100 GHz. Using the proposed model, the impact of various material properties and physical parameters on the electrical performance of the silicon-core CTSVs is investigated. It is observed that the thickness of the plated Cu and isolation dielectric are two important parameters that determine the electrical performance of silicon-core CTSVs. Performance comparison shows that the proposed silicon-core CTSVs provide a comparable performance to standard Cu-based CTSVs and better performance to the conventional signal-ground TSV pairs. The results in this paper would provide some design guides for silicon-core CTSVs in 3-D integration.

A Rigorous Proof on the Radiation Resistance in Generalized PEEC Model

This paper develops a theory on the proof of the radiation resistance in frequency-domain partial element equivalent circuit (PEEC) model. Specifically, the total power dissipated on the imaginary part of the complex inductance and capacitance derived from the PEEC model is found to be the total radiated or scattered power when the structure is internally excited by independent sources, or externally by incident waves, respectively. Accordingly, the imaginary part of the complex inductance and capacitance represents a radiation resistance network of the structure. Numerical simulations based on PEEC and commercial electromagnetic simulation tool are presented for comparison, and some physical implications are discussed.

인체 통신에 따른 인체 주변에서의 전기장 분포 계산 및 전송 손실 연구

인체 통신이란 사람의 몸통이나 피부를 전송 매질로 하여 데이터를 송수신하는 통신 방식을 의미한다. 본 논문에서는 인체 피부 표면에 닿아 있는 자유 공간을 전송 매체로 하여 데이터를 전달하는 전송 방식에 대하여, 10~30 MHz 주파수 범위에서 5 MHz 간격으로 5개의 주파수에 대하여 송수신부 사이의 전기장 분포에 대하여 수치 해석하였다. 채널 손실 계산은 총 29종의 조직으로 구성되어 있는 한국형 남성 표준 인체 모델에 상용의 툴을 사용하여 실행하였다. 계산 주파수에 따른 인체 조직의 도전율과 비유전율을 해석 파라미터로 입력하여 송수신부로 간주되는 손등 위에서 전기장 분포를 계산하였다. 손등에 부착된 송신기에 의한 전자파비(比)흡수율(SAR: Specific Absorbtion Rate) 값을 계산한 후, 국제비전리복사방호위원회(ICNIRP: International Commission on Non-Ionizing Radiation Protection) 인체 보호 기준과 비교하였다. 또한, 수치 해석으로 구한 전기장을 선(線)적분하여 인접한 극판들 사이의 전압들을 계산하였고, 송신부와 수신부의 전압의 비(比)를 채널 손실로 정의하였다. 수치 해석 결과, 10~30 MHz 주파수 대역에서 채널 손실의 범위는 약 (<TEX>$75{\pm}1$</TEX>) dB로 주파수에 따른 채널 손실의 변화가 크지 않았다. Human body communication means transmitting and receiving data through human body medium or through free space along with the human body skin. Electric field distribution around the human body between the transmitter and the receiver were calculated at five different frequencies with 5 MHz interval between 10 MHz and 30 MHz. Commercial electromagnetic simulation tool was used for the calculation of E-field distributions applying the Korean standard male model including 29 different kinds of human tissues. After calculating specific absorption rate(SAR) values on back of the hand, it was compared with International Commission on Non-Ionizing Radiation Protection(ICNIRP) human protection guideline. While conductivities(<TEX>${\sigma}$</TEX>) and relative permittivities(<TEX>${\varepsilon}_r$</TEX>) of the human tissues for each frequency were input as the analyzing parameters, electric field intensities near both hands were integrated along the integral line between the nearby electrodes for the calculation of the transmitting and receiving voltages whose ratio was defined as channel loss. The calculated channel losses were about (<TEX>$75{\pm}1$</TEX>) dB and showed nearly flat response all through the evaluated frequencies.

Simple Electromagnetic Modeling Procedure: From Near-Field Measurements to Commercial Electromagnetic Simulation Tool

As the first part of a study that aims to propose tools to take into account some electromagnetic compatibility aspects, we have developed a model to predict the electric and magnetic fields emitted by a device. This model is based on a set of equivalent sources (electric and magnetic dipoles) obtained from the cartographies of the tangential components of electric and magnetic near fields. One of its features is to be suitable for a commercial electromagnetic simulation tool based on a finite element method. This paper presents the process of modeling and the measurement and calibration procedure to obtain electromagnetic fields necessary for the model; the validation and the integration of the model into a commercial electromagnetic simulator are then performed on a Wilkinson power divider.

Optimization of Circular Ring Microstrip Antenna Using Genetic Algorithm

Circular ring microstrip antennas have several interesting properties that make it attractive in wireless applications. Although several analysis techniques such as cavity model, generalized transmission line model, Fourier-Hankel transform domain and the method of matched asymptotic expansion have been studied by researchers, there is no efficient design tool that has been incorporated with a suitable optimization algorithm. In this paper, the cavity model analysis along with the genetic optimization algorithm is presented for the design of circular ring microstrip antennas. The method studied here is based on the well-known cavity model and the optimization of the dimensions and feed point location of the circular ring antenna is performed via the genetic optimization algorithm, to achieve an acceptable antenna operation around a desired resonance frequency. The antennas designed by this efficient design procedure were realized experimentally, and the results are compared. In addition, these results are also compared to the results obtained by the commercial electromagnetic simulation tool, the FEM based software, HFSS by ANSOFT.

Design of dual-frequency probe-fed microstrip antennas with genetic optimization algorithm

Dual-frequency operation of antennas has become a necessity for many applications in recent wireless communication systems, such as GPS, GSM services operating at two different frequency bands, and services of PCS and IMT-2000 applications. Although there are various techniques to achieve dual-band operation from various types of microstrip antennas, there is no efficient design tool that has been incorporated with a suitable optimization algorithm. In this paper, the cavity-model based simulation tool along with the genetic optimization algorithm is presented for the design of dual-band microstrip antennas, using multiple slots in the patch or multiple shorting strips between the patch and the ground plane. Since this approach is based on the cavity model, the multiport approach is efficiently employed to analyze the effects of the slots and shorting strips on the input impedance. Then, the optimization of the positions of slots and shorting strips is performed via a genetic optimization algorithm, to achieve an acceptable antenna operation over the desired frequency bands. The antennas designed by this efficient design procedure were realized experimentally, and the results are compared. In addition, these results are also compared to the results obtained by the commercial electromagnetic simulation tool, the FEM-based software HFSS by ANSOFT.