Numerical Simulation-Based Investigation of the Limits of Different Quasistatic Models

The modeling of the capacitive phenomena, including the inductive effects becomes critical, especially in the case of a power converter with high switching frequencies, supplying an electrical device. At a low frequency, the electro-quasistatic (EQS) model is widely used to study the coupled resistive-capacitive effects, while the magneto-quasistatic (MQS) model is used to describe the coupled resistive-inductive effects. When the frequency increases, the Darwin model is preferred, which is able to capture the coupled resistive-capacitive-inductive effects by neglecting the radiation effects. In this work, we are interested in specifying the limits of these models, by investigating the influence of the frequency on the electromagnetic field distributions and the impedance of electromagnetic devices. Two different examples are carried out. For the first one, to validate the Darwin model, the measurement results are provided for comparison with the simulation results, which shows a good agreement. For the second one, the simulation results from three different models are compared, for both the local field distributions and the global impedances. It is shown that the EQS model can be used as an indicator to know at which frequency the Darwin model should be applied.

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Ultra-wideband elliptical patch antenna for microwave imaging of wood

International Journal of Microwave and Wireless Technologies ◽

10.1017/s1759078719000588 ◽

2019 ◽

Vol 11 (9) ◽

pp. 948-966 ◽

Cited By ~ 3

Author(s):

Tale Saeidi ◽

Idris Ismail ◽

Wong Peng Wen ◽

Adam R. H. Alhawari

Keyword(s):

Low Frequency ◽

Wide Band ◽

Microwave Imaging ◽

Ultra Wideband ◽

Uniform Illumination ◽

Elliptical Shape ◽

Measurement Results ◽

Simulation Results ◽

Strip Loading ◽

Good Agreement

AbstractThis paper presents the design of an elliptical shape ultra-wide band antenna for imaging of wood. The antenna is constructed comprising an elliptical shape of patch loaded by a stub to resonate at lower bands, strip loading at the back, and chamfered ground. Despite having miniaturized dimensions of 20 mm × 20 mm, the proposed antenna shows better results compared to recent studies. The simulation results depict a good ultra-wide bandwidth from 2.68 to 16 GHz, and 18.2–20 GHz. Besides, the proposed antenna has two low-frequency bands at 0.89–0.92 and 1.52–1.62 GHz, maximum gain of 5.48 dB, and maximum directivity of 6.9 dBi. The measurement outcomes are performed in air, plywood, and high-density wood and show a good agreement with the simulated results done using electromagnetic simulator CST. In addition to that, the measurement results of S-parameters, transmitted and received signals show a good agreement with the simulated results. Besides, the measured results illustrate a good isolation and uniform illumination among arrays as well as the received signals' shapes do not change in different environments, but only the amplitude. Hence, the proposed antenna seems to be adequate for microwave imaging of wood.

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Numerical Simulation on Thixo-Forging of Magnesium Matrix Composite

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.189-193.2535 ◽

2011 ◽

Vol 189-193 ◽

pp. 2535-2538 ◽

Cited By ~ 1

Author(s):

Hong Yan ◽

Wen Xian Huang

Keyword(s):

Numerical Simulation ◽

Matrix Composite ◽

Metal Flow ◽

Magnesium Matrix Composite ◽

Magnesium Matrix ◽

Simulation Based ◽

Prior Literature ◽

Simulation Results ◽

Computer Numerical Simulation ◽

Good Agreement

The thixo-forging of magnesium matrix composite was analyzed with computer numerical simulation based on rigid viscoplastic finite element method. The constitutive model of SiCp/AZ61 composite was established in our prior literature. Behavior of metal flow and temperature field were obtained. The differences between traditional forging and thixo-forging processes were analyzed. Results indicated that thixo-forging was better in filling cavity than forging. Simulation results were good agreement with experimental ones.

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Hybrid Dielectric Resonator Antenna Composed of High-Permittivity Dielectric Resonator for Wireless Communications in WLAN and WiMAX

International Journal of Antennas and Propagation ◽

10.1155/2012/531436 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6 ◽

Cited By ~ 2

Author(s):

Yih-Chien Chen

Keyword(s):

Wireless Communications ◽

Dielectric Resonator ◽

Simulation Software ◽

Dielectric Resonator Antenna ◽

High Permittivity ◽

Resonant Frequencies ◽

Rectangular Slot ◽

Measurement Results ◽

Simulation Results ◽

Good Agreement

The-hybrid dielectric resonator antenna consisted of a cylindrical high-permittivity dielectric resonator, a rectangular slot, and two-rectangular patches were implemented. The hybrid dielectric resonator antenna had three resonant frequencies. The lower, middle, and higher resonant frequencies were associated with the rectangular slot, rectangular patches, and dielectric resonator, respectively. Parametric investigation was carried out using simulation software. The proposed hybrid dielectric resonator antenna had good agreement between the simulation results and the measurement results. The hybrid dielectric resonator antenna was implemented successfully for application in 2.4/5.2/5.8 GHz of WLAN and 2.5/3.5/5.5 GHz of WiMAX simultaneously.

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Broad Band Equal-Length And Equal-Width Substrate Integrated Waveguide Four Channel Power Divider

Ciência e Natura ◽

10.5902/2179460x20791 ◽

2015 ◽

Vol 37 ◽

pp. 334

Author(s):

Masoud Khoubroo Eslamloo ◽

Pejman Mohammadi

Keyword(s):

Return Loss ◽

Propagation Constant ◽

Broad Band ◽

Equal Length ◽

Power Divider ◽

Substrate Integrated Waveguide ◽

Transmission Coefficients ◽

Measurement Results ◽

Simulation Results ◽

Good Agreement

In this letter a novel broad band substrate integrated waveguide (SIW) power divider is proposed. It consist of four output channels made by SIW with equal length and equal width. Design equations and process are given with mathematical analysis. The propagation constant of the output signals have been adjusted by utilize only four via in the middle of the output arms. As a result a novel equal output power divider, is obtained accordingly. The experimental results of a prototype at 10 GHz shows 3.1 GHz bandwidth in both simulation and measurement results. Return loss and transmission coefficients have good agreement with simulation results in considered band.

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Substrate integrated waveguide bandpass filter for short range device application using rectangular open loop resonator

International Journal of Electrical and Computer Engineering (IJECE) ◽

10.11591/ijece.v11i5.pp3747-3756 ◽

2021 ◽

Vol 11 (5) ◽

pp. 3747

Author(s):

Dian Widi Astuti ◽

Rizki Ramadhan Putra ◽

Muslim Muslim ◽

Mudrik Alaydrus

Keyword(s):

Short Range ◽

Return Loss ◽

Bandpass Filter ◽

Open Loop ◽

Frequency Region ◽

Substrate Integrated Waveguide ◽

Network Analyzer ◽

Measurement Results ◽

Simulation Results ◽

Good Agreement

The substrate integrated waveguide (SIW) structure is the candidate for many application in microwave, terahertz and millimeter wave application. It because of SIW structure can integrate with any component in one substrate than others structure. A kind components using SIW structure is a filter component, especialy bandpass filter. This research recommended SIW bandpass filter using rectangular open loop resonator for giving more selectivity of filter. It can be implemented for short range device (SRD) application in frequency region 2.4 - 2.483 GHz. Two types of SIW bandpass filter are proposed. First, SIW bandpass filter is proposed using six rectangular open loop resonators while the second SIW bandpass filter used eight rectangular open loop resonators. The simulation results for two kinds of the recommended rectangular open loop resonators have insertion loss (S21 parameter) below 2 dB and return loss (S11 parameter) more than 10 dB. Fabrication of the recommended two kind filters was validated by Vector Network Analyzer. The measurement results for six rectangular open loop resonators have 1.32 dB for S21 parameter at 2.29 GHz while the S11 parameter more than 18 dB at 2.26 GHz – 2.32 GHz. While the measurement results has good agreement for eight rectangular open loop resonators. Its have S21 below 2.2 dB at 2.41 – 2.47 GHz and S11 16.27 dB at 2.38 GHz and 11.5 dB at 2.47 GHz.

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Design and Performance of a J Band MEMS Switch

Micromachines ◽

10.3390/mi10070467 ◽

2019 ◽

Vol 10 (7) ◽

pp. 467 ◽

Cited By ~ 3

Author(s):

Naibo Zhang ◽

Ze Yan ◽

Ruiliang Song ◽

Chunting Wang ◽

Qiuquan Guo ◽

...

Keyword(s):

Equivalent Circuits ◽

Switching Voltage ◽

Mems Switch ◽

Switch Structure ◽

Measurement Results ◽

Switch Design ◽

Low Insertion Loss ◽

Simulation Results ◽

And Performance ◽

Good Agreement

This paper presents a novel J band (220–325 GHz) MEMS switch design. The equivalent circuits, the major parameters, capacitance, inductance and resistance in the circuit were extracted and calculated quantitatively to carry out the radio frequency analysis. In addition, the mechanical property of the switch structure is analyzed, and the switching voltage is obtained. With the designed parameters, the MEMS switch is fabricated. The measurement results are in good agreement with simulation results, and the switch is actuated under a voltage of ~30 V. More importantly, the switch has achieved a low insertion loss of ~1.2 dB at 220 GHz and <~4 dB from 220 GHz to 270 GHz in the “UP” state, and isolation of ~16 dB from 220 GHz to 320 GHz in the “DOWN” state. Such switch shows great potential in the integration for terahertz components.

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UWB Bandpass Filter with Ultra-wide Stopband based on Ring Resonator

Frequenz ◽

10.1515/freq-2016-0312 ◽

2018 ◽

Vol 72 (5-6) ◽

pp. 245-252 ◽

Cited By ~ 2

Author(s):

Maryam Kazemi ◽

Saeedeh Lotfi ◽

Hesam Siahkamari ◽

Mahmood Mohammadpanah

Keyword(s):

Bandpass Filter ◽

Ring Resonator ◽

Ultra Wideband ◽

Design System ◽

Filter Performance ◽

Full Wave ◽

Measurement Results ◽

Operational Frequency ◽

Simulation Results ◽

Good Agreement

AbstractAn ultra-wideband (UWB) bandpass filter with ultra-wide stopband based on a rectangular ring resonator is presented. The filter is designed for the operational frequency band from 4.10 GHz to 10.80 GHz with an ultra-wide stopband from 11.23 GHz to 40 GHz. The even and odd equivalent circuits are used to achieve a suitable analysis of the proposed filter performance. To verify the design and analysis, the proposed bandpass filter is simulated using full-wave EM simulator Advanced Design System and fabricated on a 20mil thick Rogers_RO4003 substrate with relative permittivity of 3.38 and a loss tangent of 0.0021. The proposed filter behavior is investigated and simulation results are in good agreement with measurement results.

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An Assessment of Heating Load Reduction by a Solar Air Heater in a Residential Passive Ventilation System

Energies ◽

10.3390/en14227651 ◽

2021 ◽

Vol 14 (22) ◽

pp. 7651

Author(s):

Junichiro Matsunaga ◽

Koki Kikuta ◽

Hideki Hirakawa ◽

Keita Mizuno ◽

Masaki Tajima ◽

...

Keyword(s):

Ventilation System ◽

Prediction Methods ◽

Solar Air Heater ◽

Load Reduction ◽

Accurate Evaluation ◽

Air Heater ◽

Simulation Based ◽

Measurement Results ◽

Heating Load ◽

Simulation Results

In this paper, the authors examined the technology to maximize the use of renewable energy. Passive ventilation systems are expected to reduce the energy consumption of the fan and the maintenance burden. In addition, the wall-mounted solar air heater can supply thermal energy without using any energy at all. Therefore, this paper presents a “passive ventilation system with a solar air heater” that combines a passive ventilation system with the solar air heater to preheat the air. This system can reduce the ventilation load. To evaluate the solar air heater performance in a real environment, we developed a simulation for calculating the heat collection capacity of the solar air heater, and then the system was implemented in a real building for verification. The simulation performs hourly unsteady calculations, allowing for accurate evaluation of the annual simulation. Based on the measurement results, the effects of heating load reduction and prediction methods are presented. The solar air heater reduced the monthly ventilation load by up to 50% or more, and by at least 15%. It was also confirmed that there was a high correlation between the actual measurements and the simulation results.

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Compact dual-band bandpass filter using open stub-loaded stepped impedance resonator with cross-slots

International Journal of Microwave and Wireless Technologies ◽

10.1017/s1759078715001786 ◽

2016 ◽

Vol 9 (2) ◽

pp. 269-274 ◽

Cited By ~ 7

Author(s):

Bukuru Denis ◽

Kaijun Song ◽

Fan Zhang

Keyword(s):

Bandpass Filter ◽

Design Concept ◽

Dual Band ◽

High Isolation ◽

Transmission Zeros ◽

Full Wave ◽

Measurement Results ◽

Stepped Impedance Resonator ◽

Simulation Results ◽

Good Agreement

A compact dual-band bandpass filter using stub-loaded stepped impedance resonator (SLSIR) with cross-slots is presented. The symmetric SLSIR is analyzed using even- and odd-mode techniques. Design equations are derived and they are used to guide the design of the circuits. Two passbands can be easily tuned by cross-slots and open stubs. Transmission zeros among each passbands are created, resulting in high isolation and frequency selectivity. An experimental circuit is fabricated and evaluated to validate the design concept. The fabricated filter is compact with 19.76 × 12.7 mm2. The measurement results are in good agreement with the full-wave simulation results.

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A novel tri-band reconfigurable microstrip patch antenna

Frequenz ◽

10.1515/freq-2019-0130 ◽

2020 ◽

Vol 74 (7-8) ◽

pp. 247-253

Author(s):

Wen Tao Li ◽

Meng Wei ◽

Bahareh Badamchi ◽

Harish Subbaraman ◽

Xiaowei Shi

Keyword(s):

Patch Antenna ◽

Simple Structure ◽

Microstrip Patch Antenna ◽

Pin Diodes ◽

Microstrip Patch ◽

X Band ◽

Measurement Results ◽

Simulation Results ◽

Good Agreement ◽

Ku Band

AbstractIn this paper, a novel tri-band reconfigurable patch antenna with simple structure is presented. By changing the on-off state of only two PIN diodes, the antenna can operate in three bands, namely X-band, Ku-band, and Ka-band. The overall size of the antenna is 0.24λL × 0.5λL × 0.019λL, where λL is the free-space wavelength of the lowest operating frequency. A prototype is fabricated and measured to verify the design. The measurement results are in good agreement with the simulation results, which indicate that the proposed antenna can be flexibly switched between three bands of 10.9–11.18 GHz, 15.65–15.9 GHz, and 32.3–33.6 GHz with stable radiation patterns.

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