EM Design, Realization and Measurement of a Hexagonal SIW-Based Bandpass Filter for Wireless Communication

In this paper a coaxial probe feed modified swastika shape patch antenna is designed and analyzed by using the finite element method based High Frequency Structure Simulator (HFSS) and Method of Moment based Applied Wave Research (AWR) Microwave Office simulation tool. Proposed Structure is investigated for different dimensions (Length and Width) of rectangular slots cut from the patch antenna to obtain the broadband frequency range in X-band (8-12 GHz). The impedance bandwidth of the proposed antenna is 16.42% with centre frequency of 9.5 GHz at-10 dB, which is further improved to 17.89% after the parametric analysis of different dimensions of the rectangular slot cuts made on the patch antenna. The simulated radiation pattern (Electric field and Magnetic field), radiation efficiency, gain (in dB), VSWR (in dB) and return loss (S11 in dB) are demonstrated for proposed structure.

In this paper, synthesis and design of hybrid-shaped cavity filters using substrate integrated waveguide (SIW) technique is proposed. Both triangular - and rectangular SIW cavities are combined for the first time in the design of band pass filter. Cross-coupling structures are realized in both proposed filters via two or three propagation paths. Measured results are presented and compared to those simulated by Ansoft's High Frequency Structure Simulator (HFSS) software package. A good agreement between the simulated and measured results is observed, which has also validated the proposed filtering structure with hybrid-shaped SIW cavities.

Background/Objectives: Modern communication devices need a multi standard, and multi functional RF(Radio Frequency) front end to utilize the communication spectrum efficiently.The objective of this paper is to design an electronically tunable frequency reconfigurable MSA(Micro Strip Antenna) operating in dual mode. Methods and Methodology: This paper presents an innovative digitally/electronically controlled frequency-reconfigurable meandered T- slot MSA for frequency reconfiguration in CR(Cognitive Radio) applications. This is designed by incorporating a modifiable slot structure in the radiating patch. The antenna was designed to resonate in dual modes. Both the modes have dual resonant frequency of operation .The frequency agility of the EM (Electro Magnetic) structure was electronically controlled by using RF-PIN diode. Coplanar waveguide (CPW) feeding was selected to allow for the integration of the MSA with (Monolithic Microwave Integrated Circuit) MMIC circuits. Findings: The simulated results for both the operational modes show a return loss for acceptable performance in Cognitive Radio applications (i.e. < -10dB). The meandered arms and side slots of the proposed meandered T-slot MSA are selected using parametric studies to get the desired resonant frequency. The first mode (Mode-1) of resonant frequencies are at Fr=2.56 GHz and Fr=5.8 GHz. The second mode (Mode-2) operating frequencies are at fro= 2.38 and fro=5.63 GHz. The proposed antenna was designed on a smaller PCB footprint of 32*42mm2 to operate in S (2-4GHz) and C (4-8GHz) bands. The Finite element method (FEM) analysis method in ANSYS- High Frequency structure simulator (HFSS) was used for full wave simulation. Frequency ratio of 2.2 and 2.32 was achieved in Mode-1 and Mode-2 respectively.

In this paper, the problem of using guard traces for reducing crosstalk between differential transmission line pairs is investigated, both experimentally and by full-wave electromagnetic (EM) simulations. Different cases of differential lines crosstalk are treated with and without guard trace separation between the differential line pairs. Coated microstrip printed circuit board test structures including thru-reflect-line calibration standards are designed and fabricated on a high frequency laminate material, allowing direct measurement of crosstalk between adjacent differential line pairs in the absence and in the presence of guard traces stitched with vias of regular spacing. The test structures are characterized with mixed-mode scattering parameters using a physical layer test system. Different configurations (of differential line pairs) without guard trace, with floating guard traces (which are terminated and nonterminated) and with a solid guard trace separation are investigated using a High Frequency Structure Simulator (a commercial full-wave 3-D EM simulation tool). The experimental data are compared with the simulation results, and some conclusions and guidelines on the effect of guard traces for alleviating crosstalk between differential transmission lines are presented

The presence of radome inevitably degrades the electromagnetic (EM) performance of the enclosed antenna while the deformation of the radome may make the degradations even worse. This letter studies the effect of structural deformation of a metal space frame (MSF) radome on EM performance. Far field of the antenna-radome system is obtained by adding the far field transmitted through skin to the scattered field of elements, both fields varying when deformation occurs. A 20-m MSF radome is employed for simulation, whose structural deformation under wind and self-weight is analyzed using finite element method (FEM). Several significative characteristics about the effect of deformation on EM performance are pointed out.

During the service process of active phased array antenna (APAA), factors such as array heating and wind loading cause significant deformation, which will seriously affect the electromagnetic (EM) performance. Obtaining the geometric parameters of the array through sensors and predicting the real-time EM performance based on the digital twin (DT) technique are crucial to guarantee the service quality of the array antenna (e.g., the detection accuracy of a target). Traditional offline simulation methods can calculate the real EM performance of APAA with geometric errors. However, it requires a large number of computational resources and computation time, which is difficult to meet the demand for real-time prediction in DT. In this article, a generalized DT framework based on the reduced-order model for APAA is proposed. First, we introduce a dynamic-static attention-enhanced convolutional network for real-time computation of key EM indicators. Then, a super-resolution generating network is proposed, which realizes the mapping of array geometrical errors to the 3-D far-field pattern, and provides support for comprehensive performance evaluation. The framework proposed in this article constructs a twin model of APAA, realizes the virtual-reality mirroring of the EM performance, and is deployed and applied in an APAA DT platform.

Intrinsic mechanism and multiphysics analysis of electromagnetic wave absorbing materials: New horizons and breakthrough

This project concerns the use of an electromagnetic sensor for the detection of leaks/cracks in water pipes. As old metal pipes corrode they start to become brittle, resulting in the potential for cracks to appear in the pipes. In addition corrosion can build up resulting in a restricted flow of water in the pipe. Using an electromagnetic (EM) wave sensor to monitor the signal reflected from the pipes in real time, provides the necessary information to determine where a leak in the pipe has occurred. Analysis of the reflected signal can provide the operator with information about the condition and position of a leak within the pipe. This is the first time research has been carried using EM waves for leak detection in water pipelines. This project involves the design and construction of an EM sensor operating at frequencies in the range of 240MHz to 560MHz, and at a power of OdBm. The sensor is launched into the water pipeline through any existing hydrant and is moved along the pipeline to check for leaks. The simulation software High Frequency Structure Simulator (HFSS) was used to model the pipe section as a circular waveguide cavity, and also for antenna simulation. The monopole and loop antenna were designed to determine the best antenna for this project. The printed circuit board (PCB) design package Eagle was used to provide the surface mount layout for the sensor, and the PCB board was fabricated by using a computer numerical control (CNC) routing machine. Finally the graphical interface package LabVIEW was used to control the frequency sweep for the sensor and to capture the data from the sensor. Based on the findings of this project, the EM wave sensor could be used to determine a leak up to a 0.9 correlation limit using low cost RF electronic devices.

This article presents electromagnetic (EM) design of a new folded-waveguide resonator filter that uses an advanced coupling scheme to achieve the desired asymmetric frequency response with an attenuation pole of finite frequency on the high side of the passband. A filter of this type with a fraction bandwidth about 5% at a center frequency of 4.45 GHz has been successfully designed using a commercially available electromagnetic simulator. The designed filter has been fabricated and tested. Simulations and experimental results are presented to validate the design and to show the advantages of this type of filter. This filter also provides a compact size compared with conventional cavity resonator filters. © 2007 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2008.

In this paper, an investigation on compact microstrip low-pass filters (MLPFs) with extremely perfect low-pass characteristics and improved out-band suppression has been carried out for the improvement of the selectivity parameter ([Formula: see text]). For this purpose, two different defected ground structures (DGSs) based on Moore fractals and Meander line have been designed and experimentally validated. The proposed third-order low-pass filter (LPF) configurations are designed and simulated using the High-Frequency Structure Simulator (HFSS). To validate the simulation models, the prototypes of the suggested low-pass filters are fabricated using Teflon (TM) substrate having a relative permittivity of 2.65 and a loss tangent of 0.001, and measured using the Vector Network Analyzer. The simulation and measurement results are in good agreement. The proposed filters occupy a compact size of [Formula: see text]. The selectivity parameter values for the proposed Moore fractals- and Meander line-modeled DGS-based LPFs are 425[Formula: see text]dB/GHz and 850[Formula: see text]dB/GHz, respectively. The proposed microstrip low-pass filters offer a significant improvement in the selectivity parameter, offering a maximum value of 850[Formula: see text]dB/GHz. The proposed filters exhibit a very high figure of merit (FOM), reporting 71,335 for Moore fractals-based LPF and 118,354 for the Meander line-based LPF. These proposed filters are suitable for advanced mobile phone services, [Formula: see text]-band radar, Global Positioning System, mobile, paging services, Wi-Fi, Bluetooth and wireless LAN.

The design and optimization of an energy harvesting antenna that can effectively capture electromagnetic energy over a broad frequency range, specifically from 2.4 GHz to several GHz, are discussed in this study. The antenna design and analysis were carried out only using the High-Frequency Structure Simulator (HFSS) tool, a highly sophisticated electromagnetic modeling programme extensively used in the field of antenna engineering. This research's main objective was to develop an antenna that could efficiently gather energy from background electromagnetic waves, especially in the frequency ranges that are often used by various wireless communication devices. Utilizing the sophisticated capabilities of the HFSS tool, which enables precise modeling of complex antenna designs and accurate projections of radiation patterns and antenna performance, the antenna design was rigorously adjusted to increase energy harvesting efficiency. The research methodology includes a number of crucial procedures. First, a comprehensive analysis of the research on energy harvesting antennas and their performance traits was conducted. After that, the modeling and simulating of various antenna designs, combinations, and parameters using HFSS started the design process. Based on simulation results, the antenna design was improved repeatedly in order to get the best performance possible within the target frequency range. The energy harvesting antenna, which was totally constructed with HFSS, functions admirably in the necessary frequency ranges of 2.4GhZ to 60GhZ, according to the results of both simulations and actual measurements. The results of this work pave the way for future improvements in wireless energy harvesting devices by providing useful insights and beneficial practical ideas for the design and optimization of energy harvesting antennas using modern electromagnetic simulation techniques.

This thesis presents novel boundary integral equation (BIE) and associated optimization methodologies for photonic devices. The simulation and optimization of such structures is a vast and rapidly growing engineering area, which impacts on design of optical devices such as waveguide splitters, tapers, grating couplers, and metamaterial structures, all of which are commonly used as elements in the field of integrated photonics. The design process has been significantly facilitated in recent years on the basis of a variety of methods in computational electromagnetic (EM) simulation and design. Unfortunately, however, the expense required by previous simulation tools has limited the extent and complexity of the structures that can be treated. The methods presented in this thesis represent the results of our efforts towards accomplishing the dual goals of 1) Accurate and efficient EM simulation for general, highly-complex three-dimensional problems, and 2) Development of effective optimization methods leading to an improved state of the art in EM design. One of the main proposed elements utilizes BIE in conjunction with a modified-search algorithm to obtain the modes of uniform waveguides with arbitrary cross sections. This method avoids spurious solutions by means of a certain normalization procedure for the fields within the waveguides. In order to handle problems including nonuniform waveguide structures, we introduce the windowed Green function (WGF) method, which used in conjunction with auxiliary integral representations for bound mode excitations, has enabled accurate simulation of a wide variety of waveguide problems on the basis of highly accurate and efficient BIE, in two and three spatial dimensions. The method provides the basic high-order singular-integration engine. Based on non-overlapping Chebyshev-discretized patches, the rectangular-polar method underlies the accuracy and efficiency of the proposed general-geometry three-dimensional BIE approach. Finally, we introduce a three-dimensional BIE framework for the efficient computation of sensitivities — i.e. gradients with respect to design parameters — via adjoint techniques. This methodology is then applied to the design of metalenses including up to a thousand parameters, where the overall optimization process takes in the order of three hours using five hundred computing cores. Forthcoming work along the lines of this effort seeks to extend and apply these methodologies to some of the most challenging and exciting design problems in electromagnetics in general, and photonics in particular.

Summary form only given. In China, there is a 1000 MW thermal power generator in operation. Large electrical machines are popular in power generation. However, large electrical machines are facing more challenges than small ones due to their features. They have high voltage, high current and high losses, which increase design difficulty in control, insulation and cooling. Moreover, the high torque in large machines will introduce challenges in mechanical designs. It's usually costly to manufacture and maintain the large machines due to their high weight and large volumes. As a result, design of large electrical machines is a complicated process. A review of the general design process of large electrical machines is presented. Firstly, the specifications of the machine should be keep in mind, such as working environment, machine type, electromagnetic performances and so on. Then the topology and parameters of the machine should be selected by optimal design. In addition, stator cooling methods, including air and water cooling, and mechanical supporting of rotor and stator, should be carefully designed respectively.In recent years, large permanent magnet (PM) machines are widely used in wind power, ship propulsion, railway traction, etc. As the capacity of electrical machines increases, there are more and more challenges in design of PM machines. When a PM machine is built and tested, it is often found that the test results do not match predictions well. A set of practical design considerations gained from industrial application experiences are presented, which should be considered during design phase, but often ignored by many machine designers. They are categorized into topology, electromagnetic (EM) performance, loss and efficiency. The causes and effects of some issues are analyzed and some solutions are suggested. They can help machine designers to narrow down the gap between design predictions and test results and build large PM machines with expected performance and high reliability. Superconducting direct-drive generators are new candidates for multi-megawatt class wind generators. Superconducting machines are famous for low weight, small size, and high efficiency. Challenges for large superconducting electrical machines are addressed. In order to find out the suitable topology for multi-megawatt-class direct-drive wind turbine generators, various designs of superconducting machines are compared; advantages and disadvantages are discussed; and a few ways to benefit from their advantages are pointed out. Moreover, characteristics of high and low temperature superconducting materials are concluded. At present, as the current cost of low temperature materials is much lower than high temperature materials. In addition, electromagnetic, mechanical and thermal challenges, including magnet design, excitation system, rotor screen, torque tube, cryogenic cooling system etc., are discussed for superconducting machines.

This paper presents a new monolithic microwave integrated circuit (MMIC) based on coplanar waveguide (CPW) design for a tunable resonator based on RF MEMS. This RF structure, which can be used for system on chip (SOC), is constituted with MEMS Bridge placed between two meander inductors and the tenability is controlled by a variable applied DC voltage. Moreover, this device presents a compactness characteristic and the possibility to operate at high frequencies. The resonant frequency and the bandwidth can be changed easily by changing the bridge gap of the RF MEMS. The numerical simulations of this novel structure of a tunable RF MEMS resonator were performed with the electromagnetic solvers CST MWS (Computer simulation Technology Microwave Studio) and validated by the more accurate electromagnetic solver HFSS (High Frequency Structural Simulator). The simulation results, for three different spacing of the bridge gap, show that the tunable frequency band are between 10 and 40 GHz with the two electromagnetic solvers and exhibiting three resonant frequencies (21, 23.1 and 24.6 GHz).The simulation results of the return loss using CST achieves 29 dB with an insertion loss less than 1 dB; However, the HFSS simulation shows similar performance in the resonant frequencies and in the bandwidth giving better results in terms of the return loss (about 35dB instead of 29 dB) and showing a good adaptation.

Recently, many contributions have been made in the full-wave analysis of package and interconnect discontinuities. Most of these contributions presented analysis of one aspect of package or one bonding wire, but very few account for multiple interacting structures of a complete package or electronic system. In addition, when the applied signal is trending to the high frequency region, electromagnetic interactions between all the bonding wires can cause the serious effects at high frequencies. The discontinuity induced by the bonding wires can significantly limit the high-frequency performance of the whole circuit and must be taken into account in the early stage of packaging designs. The exploration of extracting the model of a single bonding wire and two bond ing wires while parallel coupling and perpendicular coupling is investigated in the thesis. A method is presented to extract the equivalent circuit of bonding wires and package pin in the thesis. The Ansoft High Frequency Structure Simulator (HFSS), using the finite element method (FEM), is employed to obtain the full-wave electrical characteristics of bonding wires in the high frequency. So be the equivalent circuit model of packaging pins obtained by Q3D. Therefore, the equivalent circuit models of bonding wires and packaging pins could be established quickly. Furthermore, the inductance and capacitance values of equivalent circuit models are obtained by scaling the dimension of bonding wires. Accordingly, the lookup database of equivalent circuit’ model verse the geometrical setting of bonding wire is presented for packaging designers.