All antennas

CST STUDIO SUITE Simulations Replace Prototype Builds For Convergentia

CST STUDIO SUITE Simulations Replace Prototype Builds For Convergentia Document type
Portable devices such as smartphones and tablets nowadays contain many wireless systems, including cellular, Wi-Fi and GPS. Each system requires a functional antenna, since poor antenna performance may lead to a bad user experience in the form of low data throughput or poor coverage, and can cause calls to be dropped and car navigation to fail. On the other hand, devices must look appealing and their size must be minimized. The thinness of the devices and the presence of metallic structures have caused challenges to antenna design. Without 3D simulations, there is a high risk of having poor antenna performance or clumsy industrial design. The alternative for antenna verifi cation is to use multiple prototyping rounds, which are expensive and have a long lead time. However, there are things that cannot be effectively studied with prototypes, for example grounding structures and impedance matching networks. Read full article..

Antenna Design and Placement for the Automotive Market

Antenna Design and Placement for the Automotive Market
Whether for business or leisure, we spend an increasing proportion of our time in our cars. We have seen a corresponding increase in the implementation of all kinds of technologies in the car for entertainment, utility, and safety. A typical high-end car today has AM, FM, DAB and GSM satellite radio, tire-pressure monitoring (TPM), remote entry and start, in-vehicle TV, GPS navigation, Bluetooth, electronic toll collection, and multiple radar systems (e.g. collision avoidance, parking assistance, adaptive cruise control). Read full article..

Simulation-Enabled 5G Antenna Design

Simulation-Enabled 5G Antenna Design
Mobile communication speed requirements are rapidly increasing as the number, variety and function of mobile consumer devices flourish. To meet these needs, research and development regarding fifth generation (5G) antennas is already underway. This webinar shows the workflow and simulation features in CST STUDIO SUITE that are enabling antenna engineers to envision and design the next generation of mobile device antennas. Compact, smart antenna array concepts provide the necessary data performance, but pose a unique challenge for antenna designers. Read full article..

Airbus Defence and Space Uses CST STUDIO SUITE to Analyze Antenna Systems on BepiColombo

Airbus Defence and Space Uses CST STUDIO SUITE to Analyze Antenna Systems on BepiColombo Document type
BepiColombo is a joint mission of the European Space Agency (ESA) and the Japanese Aerospace Exploration Agency (JAXA). The aim of the mission is to send two orbiters to Mercury in order to study its atmosphere, composition and magnetic field to help understand how the planet was formed, as well as to verify some key predictions of general relativity. Airbus Defence and Space (Airbus DS) is the prime contractor for the ESA elements of the mission, including the Mercury Planetary Orbiter (MPO). The MPO includes multiple antenna systems – some of which are moveable – for telemetry, tracking and control (TTC) and scientific purposes, mounted on a single satellite bus, along with solar panels and instruments which can obstruct the antennas themselves (Figure 1). In order to ensure that the MPO functions as expected when it reaches Mercury’s orbit, Airbus DS has to investigate any possible issues that could affect antenna performance across all of the spacecraft’s different configurations. Read full article..

"Leaky" Cables Make Fine Broadband Antennas

"Leaky" Cables Make Fine Broadband Antennas
A cable that leaks electromagnetic energy sounds like a defective cable. Yet, ironically, it makes an excellent broadband antenna. To avoid confusion, antennas based on this approach are called leaky feeders. They are typically used in environments that mirror the cylindrical shape and length of the cable: tunnels, mines, aircraft, railroad tracks and skyscrapers. CST provides a tutorial explaining the basic theory and electromagnetic performance. Turning theory into practice, with assistance from W. L. Gore, we examine their use enabling Wi-Fi and cellular service on commercial airlines and corporate jets. Read full article..

Designing a Phased Array Antenna Using Antenna Magus and CST STUDIO SUITE

Designing a Phased Array Antenna Using Antenna Magus and CST STUDIO SUITE Document type
Antenna synthesis lets engineers investigate many potential designs and produce antennas that fit the specifications quickly. For effects that cannot be accounted for analytically such as edge effects and mutual coupling, full-wave 3D simulation can complement synthesis tools and allow designs to be checked and fine tuned. This article explores the synthesis of an antenna array, using a phased array satellite communications antenna as an example. Read full article..

Design und Bewertung einer Hohlleiter-Schlitzantenne (Slotted Waveguide Antenna,SWA) mit EM-Simulation

Design und Bewertung einer Hohlleiter-Schlitzantenne (Slotted Waveguide Antenna,SWA) mit EM-Simulation
SWAs sind für viele Radaranwendungen nützlich. Sie sind leicht, robust und bieten einen hohen Gewinn und eine sehr gute Richtcharakteristik. Dabei sind sie relativ einfach herzustellen. SWAs bestehen aus einem Hohlleiter, dessen Wand durch Schlitze unterbrochen ist. Read full article..

Wireless Power Transfer and Microwave Energy Harvesting

Wireless Power Transfer and Microwave Energy Harvesting
Although wireless energy transfer is an old idea (Tesla patented one design in 1901), technological advances and the rise of portable devices have made it relevant again for different applications, such as wireless charging and energy harvesting. This webinar will consist of two parts. The first part is a review of low frequency power transfer in two categories: short range-inductive charging and powering of electronic devices and electric vehicles, and mid-range power transfer through coupled resonant circuits. We will give several examples and highlight the role of simulation in the design of transfer systems. The tools in CST STUDIO SUITE® used for the design and optimization of these devices will be demonstrated, including the use of hybrid circuit-EM co-simulation to optimize matching circuits to improve link robustness. The second part of the webinar is concerned with wireless energy transfer over longer distances, where the far-field transfer of RF energy may be used. We make a distinction between harvesting RF energy from signals present in the ambient and transferring RF energy by intentionally transmitting RF signals. After a discussion of the power densities, we will continue with (intentional) RF energy transfer for powering sensors to be used in Smart Buildings. The blocks of a far field RF energy transfer system will be discussed: Transmit antenna (and maximum allowed transmit power), propagation channel and rectifying antenna or rectenna. The components of the rectenna: rectifier, dc-dc boost converter and antenna, will then be discussed. Several examples will be shown. Read full article..

MIMO Antenna Systems for Advanced Communication

MIMO Antenna Systems for Advanced Communication
Multiple-input, multiple-output (MIMO) systems are a major field of study for researchers interested in achieving high data rate communication in typical urban multi-path environments. Although a fast analysis can be based on S-parameters, this approach has limitations. A more detailed analysis needs to take into account broadband, farfield and antenna properties. These are especially important in presence of the human body. This webinar will show how simulation can be used to calculate the effect of hand and head (e.g. CTIA models) on mobile devices, MIMO for wearable antennas and different power weighting functions for different environments, along with post-processing options for envelope correlation (including spatial power weighting functions), derived quantities diversity gain and multiplexing efficiency. Finally, there will be a demonstration of the link between CST MICROWAVE STUDIO® and Optenni Lab for multiple antenna matching to optimize power transfer to antennas while minimizing cross-coupling. Read full article..

Simulation and Measurement: Complementary Design Tools

Simulation and Measurement: Complementary Design Tools
The usual aim of electromagnetic simulation in design is to lower the number of prototypes to reduce costs and time to market. However, this is only possible when the EM simulator is given the correct input data that accurately represents the physical device. Then an excellent agreement between simulation and measurement can be expected. There are many possible causes of discrepancies between the two, including geometric differences (over-etching, over-milling, rounded corners), material properties (anisotropic dielectrics, surface roughness), installed performance (surrounding structures) and feed discrepancies (connector modeling). This webinar will explore the relationship between simulation, using CST STUDIO SUITE®, and measurement, and explain what each domain is best suited for. In some situations measurement can be difficult to perform while simulation is simpler, and vice versa. Simulation allows many variations on a design to be investigated, using techniques such as parameter sweeps, sensitivity and yield analysis. The webinar will also demonstrate how simulation can be used for what-if analysis and feasibility studies at early stage of design before first prototypes. Finally, the use of measured data to calibrate simulation will be shown. This is useful for hard-to-model phenomena like surface roughness or for the modeling of low-cost adapters. Read full article..

Modeling and Simulation of Metamaterial-Based Devices for Industrial Applications

Modeling and Simulation of Metamaterial-Based Devices for Industrial Applications
The subject of metamaterials has rapidly grown over the past few years from a hot topic of academic research to a field with interesting and novel industrial applications. The exotic properties of these metamaterials include negative or low values of permittivity, permeability and refractive index, allowing engineers to manipulate the material’s intrinsic parameters to control the propagation of electromagnetic waves. Some recent industrial applications have seen metamaterial transmission lines being used in broadband filters, multiband components, dual-band tags for UHF-RFID and sensors. The metamaterial-based waveguide structures, such as composite right/left-handed (CRLH) structures, have led to interesting applications of waveguide miniaturization and novel coupler design. Metamaterial-inspired antenna design has produced reflex-cavity antennas with low-profile, high gain, beam steering and frequency agility. Read full article..

Kymeta Develops Novel Metamaterial Antennas with CST STUDIO SUITE

Kymeta Develops Novel Metamaterial Antennas with CST STUDIO SUITE Document type
Satellite broadband promises fast, flexible internet access from anywhere in the world. Although major satellite operators have already begun deploying next-generation satellites with high data throughputs, accessing these currently requires bulky, expensive equipment with high power requirements for the user. Unlocking the full potential of these data links requires an antenna solution that can track satellites while also being portable enough to attach to a vehicle or take into the field. Read full article..

Design of an Ultra-Wideband High-Power-Microwave Traveling-Wave Antenna

Design of an Ultra-Wideband High-Power-Microwave Traveling-Wave Antenna Document type
In this article we discuss the design and implementation of high-power-microwave (HPM) traveling-wave antenna. The antenna is designed to be driven by a high-power, single-shot signal generator with 1 ns pulse-width at the -3 dB power points, and peak voltage of up to 100 kV. Since the signal generator is equipped with an air-filled coaxial-waveguide output, a coaxial-waveguide to parallel-plates transition was also designed and fabricated. Initial theoretical electrical parameters and characteristics along with physical dimensions of the system were solved and derived using MATLAB[1]. Then, the components comprising the antenna were modeled, solved and optimized using CST STUDIO SUITE®[2]. Using the CAD export capabilities in CST STUDIO SUITE, fabrication models and schematics were produced from the simulation model. The antenna was fabricated and measured results agree with simulation results to a great extent. Read full article..

Integration of Savant 4.0 with CST STUDIO SUITE 2014

Integration of Savant 4.0 with CST STUDIO SUITE 2014
Detailed full wave analysis results for individual and isolated antennas can now be easily streamed into Savant V4 for an efficient workflow for installed antenna performance analysis. The high-frequency time domain, frequency domain (FEM) and integral equation (MoM) solvers in CST STUDIO SUITE 2014 can provide Savant with high-fidelity full wave antenna models for hybrid analysis to perform antenna placement studies and antenna-to-antenna analysis in Savant. Read full article..

Microstrip Patch Array Design

Microstrip Patch Array Design
This article explains the design process for a planar microstrip patch array for WLAN frequencies using the circuit and full-wave 3D solvers and optimization tools in CST STUDIO SUITE®. The goal in this case is to design an array with high directivity, low cost and low sidelobes, exhibiting a good impedance matching in the frequency range 5.18 – 5.85 GHz. The same approach can also be used to design other types of array by using a different radiator or array layout. Read full article..

Embedded Dual-Band GSM Antenna Design

Embedded Dual-Band GSM Antenna Design Document type
This application note illustrates how CST MICROWAVE STUDIO® (CST MWS), Antenna Magus and Optenni Lab can be used in combination to improve an existing GSM tracking device application. The requirement was to replace an existing “off-the-shelf” antenna on a GSM tracking device with an embedded, integrated antenna in order to reduce manufacturing and component costs. The new antenna had to operate inside the standard GSM 900 and 1800 frequency bands and had to use the existing substrate and metallic layers, without changing the existing circuit layout or the size of the PCB. The new integrated antenna was designed using Antenna Magus in combination with CST MWS to account for unwanted coupling, ensuring that the antenna operated within the desired frequency bands. Read full article..

Antenna Magus Flyer

Antenna Magus Flyer Document type
Antenna Magus is a software tool that helps accelerate the antenna design and modelling process. It helps engineers make informed choices of antenna elements from a huge antenna database and to share their proprietary knowledge with others. Good starting designs and parameterised models of antennas can be exported to CST MICROWAVE STUDIO® (CST MWS) for further design. Read full article..

Savant Flyer

Savant Flyer Document type
Savant is a leading-edge tool for simulating the installed performance of antennas located on electrically large platforms. Using a powerful high frequency EM ray-tracing engine, Savant provides the power to efficiently simulate antenna-to-platform and antenna-to-antenna coupling performance in environments involving electrically large platforms. Isolated antenna models generated by full wave EM analysis, for instance using CST MICROWAVE STUDIO® (CST MWS) may be simulated on a full platform model (ship, airframe, vehicle) in Savant to obtain a full antenna-to-antenna coupling or installed antenna pattern result. Read full article..

CST Defense Flyer

CST Defense Flyer Document type
Aircraft, ships, land vehicles and satellites represent some of the most demanding and complex electromagnetic environments. CST STUDIO SUITE brings together 20 years of experience in the simulation of 3D microwave & RF components, antennas and systems. It is used by government agencies and defense contractors worldwide on a daily basis for mission-critical projects. Read full article..

Wearable Antennas for Body Centric Wireless Communication

Wearable Antennas for Body Centric Wireless Communication
Wireless body area networks are an increasingly important area of research and show great promise for monitoring and communication in diverse application areas such as healthcare, public safety and defence. The antenna is the crucial enabling component which allows communication between sensors, and with other off-body systems (e.g. GPS and GSM). But the antenna operates in a particularly challenging environment, in close proximity to the human body, and its performance may be affected by deformation, e.g. if integrated directly into clothing. The design of these antennas is thus challenging, and numerical simulation is an indispensable tool for the antenna engineer. This webinar will discuss the key challenges in the virtual prototyping of body worn antennas, describing how CST MICROWAVE STUDIO can be used to construct realistic flexible and conformal geometries, and how these can be studied and optimized in the context of their body-centric environment. Read full article..

Pulse Electronics improves antenna evaluation and reduces product design lead time with CST MICROWAVE STUDIO

Pulse Electronics improves antenna evaluation and reduces product design lead time with CST MICROWAVE STUDIO Document type
Pulse Electronics Mobile Division produces compact antennas for mobile communications and networking. Mobile antennas need to function in complex and mechanically limited environments, and so most antennas used today are specially designed and customer-specific. Read full article..

Antenna Cosite Interference Analysis in a Unmanned Aerial Vehicle UAV

Antenna Cosite Interference Analysis in a Unmanned Aerial Vehicle UAV
Whenever we have multiple transmitters and receivers co-located on a common platform such as a UAV, we must take care to ensure that all systems operate as intended. The RF environment will be very dense and the probability of co-site interference high. Analysis plays an increasingly important role in identifying the cause of interference and ensuring compatibility between the various RF systems. Through a recent collaboration with Delcross Technologies and interfacing with their EMIT tool, CST is providing a complete workflow for true cosite analysis. This webinar presents the full workflow including rapid synthesis of antenna models, broadband antenna coupling analysis and prediction of interference between transceivers including effects such as spurious harmonics, intermodulation and radio de-sensitization. Read full article..

Integrated Antenna Design for a GSM Tracking Device

Integrated Antenna Design for a GSM Tracking Device
A common strategy when designing an electronic communication device is to use an off-the-shelf antenna. Although the ease with which such antennas can be obtained is a certain benefit, the designer is limited to commercially available antennas which may not be of the right shape for the application, and when purchased in bulk, could become quite costly. In this webinar we aim to illustrate, through demonstration of a real world example, how an existing chip antenna on a GSM tracking device designed to monitor the acceleration (and thus level of distress) of sheep, can be replaced by an embedded, integrated antenna. The final design shows improved antenna performance and communication range while adhering to the technical and spatial requirements. In addition, its planar nature allows it to be integrated with the existing PCB layout, resulting in reduced manufacturing and assembly time and costs. The webinar will show how the design capabilities of Antenna Magus, a searchable database of antennas, can be combined with the full-wave 3D electromagnetic simulation tools in CST STUDIO SUITE to create an embedded design, where full coupling in a complex environment can be taken into account Read full article..

Matching circuit optimization for antenna applications

Matching circuit optimization for antenna applications Document type
Impedance matching is an essential part of antenna design. The input impedance of an antenna needs to be reasonably close to the amplifier impedance (e.g. 50 Ohm), otherwise the signal is reflected back to the amplifier and not radiated by the antenna. In many applications matching circuits consisting of discrete inductors and capacitors, or transmission lines are used to improve the impedance matching characteristics of the antenna. This white paper discusses the optimization of matching circuits especially to antenna applications. Although the design of matching circuits sounds simple, there are many practical considerations that need to be addressed. Read full article..

Optimization of a Reflector Antenna System

Optimization of a Reflector Antenna System Document type
In this paper a modular approach using the so-called System Assembly and Modeling (SAM) of CST STUDIO SUITE® is used to optimize a reflector antenna system in a piecewise manner. The results are compared to a full system simulation. It is shown that a similar accuracy to that of the full system simulation can be attained with the modular approach with a much shorter simulation time and using less computational resources. Read full article..

Installed Performance of Communication Antenna Arrays

Installed Performance of Communication Antenna Arrays Document type
The presence of multiple communication antennas on a tower means that antennas may have to be installed in sub-optimal positions. Electromagnetic simulation can be used to design the antennas themselves, and also to optimise the positioning of the antennas on the tower. This article will describe how multiple solvers in CST MICROWAVE STUDIO® can be combined to predict where to install an omnidirectional stacked bicone antenna array to minimise loss of omnidirectionality. Read full article..

A Square Loop Antenna Using Hybrid High Impedance Surface and Four Way Wilkinson Power Divider

A Square Loop Antenna Using Hybrid High Impedance Surface and Four Way Wilkinson Power Divider
A simulation of a planar Square Loop Antenna (SLA) on a Hybrid High Impedance Surface including the feeding part using a 4 way Wilkinson power divider is shown in this article. Placing the planar antenna over a hybrid High Impedance Surface (HIS) can lower the overall antenna profile due to the unique reflection phase of the HIS. The planar SLA produces a semi doughnut radiation pattern which is suitable for vehicular communication. The effect of the feed network and cables on the antenna performance is considered. Read full article..

Plasmonic Nano Antennas Simulation with CST MICROWAVE STUDIO®

Plasmonic Nano Antennas Simulation with CST MICROWAVE STUDIO®
This paper is based on: "Comparison of electromagnetic field solvers for the 3D analysis of plasmonic nano antennas" by Johannes Hoffmann, Christian Hafner, Patrick Leidenberger, Jan Hesselbarth, Sven Burger, Proc. SPIE Vol. 7390, pp. 73900J-73900J-11. The Field Distribution inside a 1 nm wide gap between two 80 nm diameter Gold spheres is calculated and compared to a semi analytical reference solution published in the paper. Both general purpose solvers of CST MICROWAVE STUDIO® are used. The simulation results agree closely with the reference solution. Read full article..

Intelligent Representation of Anechoic Chamber Wall Cuts Electromagnetic Simulation Time 95%

Intelligent Representation of Anechoic Chamber Wall Cuts Electromagnetic Simulation Time 95%
Electromagnetic simulation of anechoic chambers is a very difficult task. Gwenaël Dun, R&D Engineer for Siepel, used a variety of different electromagnetic simulation tools to address this challenge in the past but ran into problems with both poor accuracy and long compute times. He then worked with the developers of CST MICROSTRIPES™ electromagnetic simulation software, to implement a feature that makes it possible to model the ferrite absorbers used in the chamber as a boundary condition rather than part of the computational domain. This change made it possible to increase mesh size by a factor of 15, reducing compute time by more than 95%. The simulation results provided a near-perfect match to physical testing. Read full article..

Electromagnetic Simulation of Composite Materials and Cable Harnesses in Aircraft

Electromagnetic Simulation of Composite Materials and Cable Harnesses in Aircraft
This webinar will discuss efficient EM modeling techniques for simulating composite materials such as carbon fiber laminates at the full aircraft level. The impact of composite materials on electromagnetic effects including installed antenna performance and lightning strikes will be explored. The webinar will also highlight recent advances in cable harness modeling and the effect of different shielding and grounding/bonding schemes for installation in aircraft. Read full article..

Evaluation of Implantable Antennas in Anatomical Body Models

Evaluation of Implantable Antennas in Anatomical Body Models
This article from researchers at the University of Liverpool demonstrates the use of voxel models for analysing implantable antenna designs, and compares homogeneous and heterogeneous body models. Read full article..

Reconfigurable Antenna Simulation

Reconfigurable Antenna Simulation
Packing more functionality into ever smaller spaces has made reconfigurable antennas very attractive for telecommunications engineers, especially given the ever expanding landscape of cellular network standards. As with any other antenna application, virtual prototyping is extremely important for accelerating the product design cycle and reducing time to market. This webinar will introduce the concepts involved in making antennas reconfigurable – for example tunable materials, mechanical reconfigurability, and RF MEMS and PIN diode switches – and will address how these can be simulated efficiently using the advanced tools in CST STUDIO SUITE 2011. Read full article..

Optimization of a Reflector Antenna System Webinar

Optimization of a Reflector Antenna System Webinar
The optimization of high gain reflector antennas presents a real challenge for conventional simulation tools. The range of geometric sizes and physical operating principles means that significant improvements in simulation time can be obtained by the clever combination of different numerical techniques. This webinar will describe how the new smart assembly mode simulation system in CST STUDIO SUITE 2011 enables the engineer to model complex reflector antenna and feed systems efficiently and accurately. Read full article..

A Two-Way Link between CST STUDIO SUITE and Optenni Lab

A Two-Way Link between CST STUDIO SUITE and Optenni Lab
A short video demonstrating the two-way link between CST STUDIO SUITE® and Optenni Lab. Read full article..

Simulation Enabling In-flight Connectivity

Simulation Enabling In-flight Connectivity
Webinar recording of the CST Leading Technology Webinar Series 2011 - Mobile phone and wi-fi communication while travelling by air is now being offered by several airlines and will become standard in future. Ensuring a reliable link depends on having properly designed antennas for the in-aircraft picocell base-stations and for the satellite or ground links outside the aircraft. Read full article..

EMC/E3 analysis of rotorcraft electrical system exposed to antenna radiation and incident EMP

EMC/E3 analysis of rotorcraft electrical system exposed to antenna radiation and incident EMP
This webcast discusses the application of full wave modeling to predicting EMC/E3 performance in a rotorcraft. We start by investigating the coupling from a blade installed on the fuselage to internal cable systems. CST CABLE STUDIO is used to efficiently and accurately model the bi-directional interaction between electromagnetic fields and the complex cable system. True transient co-simulation enables direct time-domain analysis of voltages and currents induced in cable systems, due to an incident EMP. Finally, non-linear components are added to the model to assess the performance of transient protection devices (TPD’s). Read full article..

Electromagnetic Simulation in Radar System Design

Electromagnetic Simulation in Radar System Design
This webcast will discuss the application of CST STUDIO Suite to a full radar system design. CST’s complete simulation technology enables the most appropriate method/solver to be applied to the diverse range of components typically found in a radar system. For the digital design, combined PCB/package analysis is necessary to achieve adequate signal integrity and minimize interference/emissions Read full article..

A Dielectric Lens Antenna with Enhanced Aperture Efficiency for Industrial Radar Applications

A Dielectric Lens Antenna with Enhanced Aperture Efficiency for Industrial Radar Applications
The dielectric lens antenna has been developed and applied for measuring the tank filling level in the industrial storage tank. A compact antenna with high beam is required in this application field, since the size of the antenna is limited by the size of the flange. This dielectric lens antenna has been simulated and optimized using CST MWS Transient domain solver and it shows a good agreement with the measurement. Read full article..

Simulation of Mobile Phone Antenna Performance

Simulation of Mobile Phone Antenna Performance
The telecommunications sector is making great advances aimed at delivering an even stream of high tech devices, covering the significant consumer demands in this sector. EM simulation is increasingly becoming an indispensable tool in the design flow, not only on the antenna level but also on the phone and environmental levels. This article compares simulated results with measurements for several steps in the phone design chain. Read full article..

Simulation and Construction of Body Coil substitute at 7T Whole Body MRI-System with Travelling Wave Concept

Simulation and Construction of Body Coil substitute at 7T Whole Body MRI-System with Travelling Wave Concept Document type
Tim Herrmann, Johannes Mallow, OvG University Magdeburg Magnetic resonance imaging (MRI) is one of the most important non-invasive examination methods in the modern medicine. To raise up examine possibilities, MRI systems with more powerful magnetic fields are constituted. The standard high-field whole body (1.5T-3T) MRI Systems (Fig. 1) are using a body coil for the excitation. MRI at ultra-high-field (UHF) requires different Tx-coils for excitation of different body parts since the construction of one large body coil, similar to those at lower fields, is to difficult. Moreover, at 7T B1 is inhomogeneous as the RF-wave length within the object is smaller than the object extensions. While in RF-coils the usable B1-field is restricted to dimensions and geometry of the RF-coil itself, with the new travelling wave concept, described by Brunner [1], the usable B1-field is restricted to the dimensions of the waveguide (RF-shield) only. Thus the MR travelling wave concept allows excitation of large volumes depending on the length of the RF-shield. For an antenna with a frequency of 297MHz the approximate wavelength is about 1m. Thus the RF-shield of the gradient coil with a diameter of 64cm can be used as a waveguide, because of the cut-off frequency. The cut-off frequency is the minimum frequency where a wave fits into the waveguide without damping. This study examines the use of the travelling wave concept as an efficient body coil replacement in UHF MRI-System with the support simulations in CST Microwave Studio 2009 and measurements. Therefore two different types of antennas have been simulated and produced. The B1-field distribution of a dipole and a patch antenna where simulated and compared with B1-field measurements in a 7T MRI System. The efficiency compared to a 1.5T body coil was investigated. Further research goals are to create biological models based on anatomical MRI-Dataset for use in field-simulation software with dynamic thermal solver for more realistic SAR calculation. However the remaining problems of exposing sensitive body parts, such as the human head by increased SAR needs to be solved for next generation UHF MRI-Systems. Read full article..

Optimization of a small wideband Antenna using CST and Mode Frontier

Optimization of a small wideband Antenna using CST and Mode Frontier Document type
Yael Kaldor, Rafael This work describes the simulation and optimization processes of a small antenna located on a large platform. (The platform size is 13? x 3? x 3?). The required antenna frequency performance is wideband and it is required to perform under severe environmental conditions. The antenna structure was modeled and simulated using CST (MWS) for return Loss and Radiation Pattern performance. The antenna model was parameterized to allow future optimization. The Return Loss specification for the Antenna was -8 dB maximum (VSWR 2.2:1) over a 30% bandwidth. Simulated Return Loss was initially poor over the full frequency range (sufficient performance was obtained over 6% bandwidth only). See Figure 1. The Antenna model was optimized using Mode Frontier for Return Loss performance over the full frequency range. The optimization results are depicted in Figure 2. The Return loss and VSWR performance were highly improved using the optimization process. 34% bandwidth was obtained. Read full article..

Antenna design for the detection of alive buried victims under thick layers of rubble

Antenna design for the detection of alive buried victims under thick layers of rubble Document type
Floc’h Jean Marie, IETR The antenna is used with UWB Radar techniques in order to locate buried alive victims. The detection is based on the signature of alive persons by using Doppler analysis of movements and respiration. Detecting victims in this environment is very difficult due to the large dynamic range of signal levels. In fact, the reflected signal caused by the buried alive victim is very low behind other reflected or disturbing signals such as mobile phones, vegetation movements, water, rescuers… A two flares UWB antenna, light weight and easy transportable has been specially design for the research of buried victims beneath building rubble. This paper focuses on antenna design, simulation using CST software and measurement. These measurements have been made by IETR and CEA. The experimental results show a good comparison between measurements and simulations. The goals for the design were: - Frequency band: 300 MHz – 3 GHz - Compact antenna - Gain around 10 dBi at the center frequency - Low back side radiation - Good impulse response - Very light weight antenna Read full article..

An efficient approach for wide angle scattering analysis of TT&C antennas on satellite

An efficient approach for wide angle scattering analysis of TT&C antennas on satellite Document type
Marcello Zolesi, Thales Alenia Space The scope of the present work is to analyze the effective coverage of TT&C subsystem of a LEO satellite at an altitude of 700 kilometres. The antenna assembly is made of two units, Main and Fill-In Antennas, accommodated on opposite sides of the spacecraft. Starting from the free-space radiation performance of each of the two antennas, the problem to predict the global TT&C subsystem radiation pattern in presence of the spacecraft is treated in order to identify potential blind areas or interferences caused by the neighbouring structures. The prediction of electromagnetic field scattered in complex environment is usually a hard task since the solution cannot generally be expressed in a simple and/or closed analytical form. Therefore a variety of numerical methods have been developed in literature. The effectiveness of a single method depends on the type of the electromagnetic environment and the working frequencies. The calculations of the global TT&C subsystem radiation pattern in presence of the main spacecraft structures are carried out by means a full-wave electromagnetic software, CST Microwave Studio Integral Solver. The Integral Solver is ideally suited for electrically large structures respect to the wavelength, when dominated by electrical conductors. This solver uses a combination of an open boundary integral formulation and a Multilevel Fast Multi-Pole Method (MLFMM) exhibiting an optimal complexity in terms of memory and simulation time compared to the traditional Method of Moment (MoM). Key-words: Coverage, EIRP, MLFMM, MoM, TT&C antennas. Read full article..

Environment-Independent Miniature Antennas

Environment-Independent Miniature Antennas Document type
Hubregt J. Visser, PhD, Holst Centre – IMEC-NL Antennas, when brought into close proximity with RF reflective objects or lossy human tissue, will show a degradation in performance. This degradation is visible in the input impedance as a function of frequency and in the radiation pattern, gain and efficiency. In the presentation we will show two examples of miniature antennas designed for on-body use that exhibit a negligible performance degradation when brought near or onto the human body. One of the examples comprises a miniature, curved microstrip patch antenna for application on the wrist, see Figure 1. Here, the ground plane of the patch antenna has been used to form a shielding between antenna and environment. The other example is a CPW printed monopole antenna, embedded in a low-loss dielectric body to contain the fields and thus minimize reactive tuning, see Figure 2. Furthermore the short ground plane of this antenna has been modified to suppress coaxial cable current radiation. In the designs, the human body has been modeled as a curved, layered medium consisting of skin, fat, muscle, bone and, when appropriate, dura, cerebrospinal fluid and brain tissue. The CSTMWS designs, the realized prototypes and the measurement results will be presented. Figure 1: Curved microstrip patch antenna for use on the wrist. Figure 2: Printed monopole antenna in proximity to the human body. Read full article..

X-Band Squintless Horn Antenna Array (96 elements)

X-Band Squintless Horn Antenna Array (96 elements)
This article concerns the design of a X-Band squintless horn antenna array consisting out of 96 radiating elements. The full design of the 2.4m antenna blank (including the simultaneous excitation of all 96 arms) has been performed within CST MICROWAVE STUDIO®. The simulated results have been in an excellent agreement with compact range measurements. Read full article..

Advanced Modelling and Measurement of Wideband Horn Antennas

Advanced Modelling and Measurement of Wideband Horn Antennas
This paper presents the excellent correlation of measurement results to the numerical calculations of a SATIMO dual-ridge horn antenna which include the directivity, boresight gain, and return loss vs. frequency. The structure is electrically large which lends itself, as a result of its efficient memory utilisation, to the CST MICROWAVE STUDIO® (CST MWS) Time Domain Solver. Broadband, high resolution gain results can be obtained within a single run with as many as 100 farfield monitors being defined. The results are presented with the courtesy and permission of SATIMO, Italy. Read full article..

The use of CST Microwave Studio in the Design of an X-Band Circularly Polarised Splashplate Antenna

The use of CST Microwave Studio in the Design of an X-Band Circularly Polarised Splashplate Antenna Document type
Richard Roberts, Astrium Ltd This presentation describes how CST Microwave Studio (MWS) has been used in conjunction with POS 5 and GRASP 8 to design an X-Band circularly polarised Splashplate Antenna. The antenna essentially consists of a centre fed reflector (17 wavelengths in diameter), the Splashplate feed (~2 wavelengths in diameter), and a septum polariser to allow the Tx and Rx bands to operate in opposite polarisations. A significant factor in the design is that a short circuit had to be assumed at the other port of the septum polariser meaning that the return loss of the Splashplate feed and the reflector were critical to the axial ratio performance. CST MWS enabled this aspect of the design to be modelled and analysed using the T-solver. Comparison of the measured and predicted antenna performance has validated the design process. Although a compliant performance has been achieved, it is evident that some modelling improvements could be sought in order to get a better convergence between prediction and measurement. Read full article..

On the determination of the impulse response of Ultra-wideband antennas

On the determination of the impulse response of Ultra-wideband antennas Document type
Sebastian Sczyslo, Gunnar Armbrecht, Holger Thye, Sven Dortmund, Thomas Kaiser, Leibniz Universität Hannover This contribution deals with the accurate determination of the impulse response of Ultra-wideband (UWB) antennas both by simulation and measurement. As can be found in recent literature, knowledge about the impulse response does not only allow for the derivation of further antenna parameters such as gain or group delay, but also to design more efficient receivers and to run more realistic simulations. Here we will exemplarily use the cone antenna as the antenna under test (AUT), as this is a very prominent antenna type in the field of UWB. In the first part CST Microwave Studio (CST MWS) is used to model and simulate the antenna in the transmit case. To extract the radiated E-Field, we developed a new macro based on the transient broadband farfield monitor. Applying this macro is time-saving compared to the conventional method using farfield probes which can be found in many publications. The transmit impulse response is determined by a deconvolution operation. Finally Lorentz reciprocity is used to evaluate the receive impulse response as it is common in literature. In the second part the obtained simulation results from CST MWS will be compared to measurement results. At this we will not only use the conventional two-antenna method but we will also introduce the GTEM method, as a fast and accurate antenna measurement method. We developed this novel method based upon our previous research in the field of GTEM cells and it allows for a direct determination of the receive impulse response using a single antenna only. Read full article..

Designing a Band Notch Filter for a UWB Antenna Using CST MWS

Designing a Band Notch Filter for a UWB Antenna Using CST MWS Document type
Ad Reniers, Technical University Eindhoven High-data-rate wireless communications need wide bandwidths. In the Ultra-Wideband (UWB) frequency band from 3.1 GHz to 10.6 GHz, information may be spread over a large bandwidth at low power levels thus creating the possibility to share the spectrum with other users. To prevent interference with existing wireless systems, like IEEE 802.11a WLAN, stop band characteristics are required from 5 GHz to 6 GHz*. The notch filter function is designed in a low-cost circular planar dipole antenna based on the ‘two-penny’ dipole. To achieve the required specifications for this notch function we used first the CST optimizer. After that we optimized systematic the design. In this presentation we want to show the results of both approaches to achieve a maximum result and try to understand the working of this notch and spur function in this compact UWB antenna. * Paper: Low-cost, compact UWB antenna with frequency band-notch function. H.J. Visser. Read full article..

TLM Simulation of Human Exposure to 400MHz Electromagnetic Fields Inside a Car

TLM Simulation of Human Exposure to 400MHz Electromagnetic Fields Inside a Car Document type
Transmitters used in vehicle environments present potential threats to the health and safety of vehicle users, in terms of both human exposure to electromagnetic fields and vehicle EMC (electromagnetic compatibility). The recently revised automotive EMC directive (2004/104/EC) now requires vehicle manufacturers to identify acceptable frequencies, powers and antenna installations that can be used on vehicles without compromising their EMC performance. The simulations presented here were performed with CST MICROSTRIPES™. Read full article..

Mobile Phone Simulations with Human Head and Hand Models

Mobile Phone Simulations with Human Head and Hand Models
Human head models like the SAM phantom are already regularly used to test the influence on mobile phone performance as well as to check the compliance to SAR standards. However, the hand also influences the field distribution significantly. The following article shows the CST MICROWAVE STUDIO® (CST MWS) simulation results of a complete Sony Ericsson mobile phone in relation to head and hand phantoms. Read full article..

RFID Reader-Coil, 13.56 MHz

RFID Reader-Coil, 13.56 MHz
Radio Frequency Identification Systems (RFID) are widely used and allow advanced solutions for a variety of applications in the area of authentication, ticketing, access control, supply management, parking, payment, vending,etc. The example presented here is a RFID Readercoil "P81" from Legic Ident Systems and was modeled and solved using the frequency domain solver of CST MICROWAVE STUDIO® (CST MWS). The sensitivity of the computed complex input impedance with respect to substrate tolerances is computed and was compared to measurement data. Read full article..

RFID Transponder operating at 13.56 MHz

RFID Transponder operating at 13.56 MHz
Radio Frequency Identification Systems (RF-ID) are widely used and are thus one of the fastest growing sectors of todays radio industry, allowing advanced solutions for a variety of applications in the area of authentication, ticketing, access control, supply management, etc. One of the most common band allocated to RFID systems is 13.56 MHz. For this application example operating at this particular frequency band we have chosen a transponder inlay which was created using the ACIS based solid modeler of CST MICROWAVE STUDIO® The frequency domain solver of CST MICROWAVE STUDIO® has been applied to accurately predict the input impedance, followed by a lumped element based equivelent circuit derivation to describe the impedance versus frequency. Read full article..

Optimizing antenna design and placement in MIMO systems

Optimizing antenna design and placement in MIMO systems Document type
J.Fejfar, CST of America. Video of a webinar presentation (Running time: 11 min) Read full article..

Theory and applications of MIMO in radar systems

Theory and applications of MIMO in radar systems Document type
J. Guerci , Consultant, VA, USA. Video of a webinar presentation(Running time: 33 min) Read full article..

Introduction to MIMO and its advantages for mitigating multipath in wireless deployments

Introduction to MIMO and its advantages for mitigating multipath in wireless deployments Document type
K. Carrigan, Senior Systems Engineer, U.S. Navy (NSWC Dahlgren), & D. Johns, CST of America. Video of a webinar presentation (Running time: 32 min). Read full article..

Ultra-Wide-Band Printed Circular Dipole Antenna

Ultra-Wide-Band Printed Circular Dipole Antenna
A UWB dipole antenna composed of circular arms containing a special feeding system is modeled simulated using CST MICROWAVE STUDIO®, the results of which are presented in this article. The design, developed by IETR-INSA / Thomson R&D France, shows good broadband matching (3-10 GHz) and an omnidiectional radiation pattern up to 6 GHz. Read full article..

Multiple Band-Notched Planar Monopole UWB Antenna

Multiple Band-Notched Planar Monopole UWB Antenna
A multiple band-notched planar monopole antenna for multiband wireless systems is presented. The proposed antenna consists of a wideband planar monopole Antenna and the multiple U-shape slots, producing band-notched characteristics. This technique is suitable for creating ultra-wideband (UWB) antenna with narrow frequency notches or for creating multiband antennas. Various antenna configurations were simulated with CST MICROWAVE STUDIO®. Read full article..

Phase Center Computation of a Corrugated Horn

Phase Center Computation of a Corrugated Horn
For a customer given corrugated horn the phase center has been computed using CST MICROWAVE STUDIO® and compared with measurement data. The simulated results are in very good agreement with measurements. Measurements were provided with courtesy and permission of Kathrein Werk KG, Rosenheim, Germany. Read full article..

Design of Circularly-Polarized Patch Antennas using CST MICROWAVE STUDIO®

Design of Circularly-Polarized Patch Antennas using CST MICROWAVE STUDIO®
An RFID Reader Antenna with the following specifications was designed: - Frequency: 908.5 - 914 MHz (In Korea) - VSWR: less than 2 with 50-ohm impedance - Polarization: circular - Axial ratio: less than 3 dB @ 908.5 - 914MHz - Gain: 6 dBi @ 1W transmitted power - Size and weight: as small as possible This article is published with the permission and courtesy of Prof. Bierng-Chearl Ahn and his colleagues at Chungbuk University, Korea. Read full article..

Ferrite-loaded waveguide antenna

Ferrite-loaded waveguide antenna
The behaviour of a ferrite loaded waveguide antenna is predicted first by a 2D-analytical model and second by CST MICROWAVE STUDIO®. The results of the predictions are compared with measurements. (Courtesy and permission of KAIST Korea.) Read full article..

Analysis of a high efficiency reflector feed array

Analysis of a high efficiency reflector feed array
This article demonstrates the application of CST MICROWAVE STUDIO® (CST MWS) to the analysis of large reflector feed arrays. An array consisting of 19 elements was simulated but a larger array of more than 100 elements may also be simulated since the memory scaling with mesh cells in CST MWS is almost linear. The simultaneous excitation feature in CST MWS was applied to obtain farfield patterns in just a single simulation. A parameter sweep was also carried out to obtain the S-Parameters as a funtion of element feeding postion. Read full article..

A Unit Cell Model of a Single Periodic Waveguide Phased-Array Antenna

A Unit Cell Model of a Single Periodic Waveguide Phased-Array Antenna
In this article a single periodic open-ended waveguide phased-array antenna with a dielectric radome at its aperture of variable thickness is analysed. As a verification it is shown that the superposition of two independent plane waves shows the same field pattern as the one created by the unit cell model. Read full article..

SAR - Spherical Phantom Model

SAR - Spherical Phantom Model
A standardized spherical phantom head such as the one described in this example is commonly used for SAR investigations and measurements. Read full article..

A Small, Efficient, Linear-polarized Omni-directional Antenna

A Small, Efficient, Linear-polarized Omni-directional Antenna
Nearly full-sized performance from a spherical coil only 1/6th as long in the E-plane normal direction as a half-wave dipole antenna. Read full article..

A Dual-Mode Conical Horn Antenna for Rotationally Symmetric Beam

A Dual-Mode Conical Horn Antenna for Rotationally Symmetric Beam
CST MICROWAVE STUDIO® has been succesfully applied to the simulation of a wide-band dual-mode horn antenna which exhibits a rotationally symmetric beam and low side-lobe levels. Read full article..

Antenna Placement on a Box

Antenna Placement on a Box
In this article the new I! Solver of CST MICROWAVE STUDIO® is used to calculate the input impedance of a monopole antenna on a conducting box. This simple example demonstrates the accuracy of the Integral Equation Solver. Geometry and results are from the paper "The Input Impedance of a Monopole Antenna Mounted on a Cubical Conducting Box“ by Shyamal Bhattacharya, Stuart A. Long, Donald R. Wilton. IEEE Transactions on Antennas and Propagation, Vol. AP 35, No. 7, July 1987. The Read full article..

Simulation of a compact antenna

Simulation of a compact antenna
This article demonstrates the simulation of an electrically large antenna. The design and numerical results are courtesy and permission of Chelton Antennas, France. The antenna operates at 8 GHz and was simulated using the CST MICROWAVE STUDIO® Transient Solver which is, as a result of its efficient memory scaling, ideal for such electrically large structures - the dish diameter in this example is approximately 20 wavelengths in size. Read full article..

Terahertz broadband metal-dielectric near-field antenna

Terahertz broadband metal-dielectric near-field antenna
The article presents an antenna-based approach to near-field imaging and spectroscopy, which can be used for both continuous-wave and pulsed broadband electromagnetic radiation from microwave to terahertz frequencies. CST MICROWAVE STUDIO® (CST MWS) was used to perform the simulations. Read full article..

Printed Dipole Antenna with Integrated Balun

Printed Dipole Antenna with Integrated Balun
This note shows simulation results for a printed Dipole Antenna with integrated Balun. The design is based on the article "3-D FDTD Design Analysis of a 2.4-GHz Polarization-Diversity Printed Dipole Antenna With Integrated Balun and Polarization-Switching Circuit for WLAN and Wireless Communication Applications" by Huey-Ru Chuang, and Liang-Chen Kuo, IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 51, NO. 2, FEBRUARY 2003 Read full article..

Vivaldi Antenna

Vivaldi Antenna
Microwave Engineering Europe's (MWEE) EM simulation benchmark has become quite a tradition over the last few years, enticing some of the best known software providers to put their diverse simulation methods to the test. Read full article..

Pillbox Antenna

Pillbox Antenna
This huge Pillbox Antenna was optimised by one of our customers even during the evaluation period of CST MICROWAVE STUDIO Read full article..

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