| 1. |
- Joseph, Laya, et al.
(författare)
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Non-Invasive Transmission Based Tumor Detection Using Anthropomorphic Breast Phantom at 2.45 GHz
- 2020
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Ingår i: 2020 14th European Conference on Antennas and Propagation (EuCAP). - 9788831299008 - 9781728137124
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Konferensbidrag (refereegranskat)abstract
- Breast cancer detection using microwave imaging techniques is a widely explored research field. In this paper, we propose the development of a heterogeneous, semi-solid and stable breast phantom with skin, fat, muscle and spherical tumor inclusion models and a transmission-based sensing method for non-invasive tumor detection. The proposed breast phantom emulates the anatomical, physical and dielectric properties as human breast tissues. The dielectric properties of the breast phantom is measured using open ended coaxial slim probe from Keysight Technologies and is compared with the Nello Carrara Institute of Applied Physics (IFAC) data in the frequency range of 500 MHz - 20GHz. The S 21 scattering parameter is measured and studied for a normal breast phantom and the breast phantom with tumor inclusion models representing its different growth stages using Topology Optimized Planar Antenna (TOPA) based probe. The measurements are done by using FieldFox microwave analyzer (N9918A) by Keysight Technologies. The study shows S 21 amplitude variation of 2 - 12 dB for tumor inclusion models of size ranging from 4mm - 16mm diameter with respect to normal breast model. This study indicates that with further development, transmission-based methods can be used for preliminary screening of breast tumor.
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| 2. |
- Mandal, Bappaditya, et al.
(författare)
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A Low Profile Button Antenna with Back Radiation Reduced By FSS
- 2020
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Ingår i: 2020 14th European Conference on Antennas and Propagation (EuCAP). - 9788831299008 - 9781728137124
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Konferensbidrag (refereegranskat)abstract
- In this article, a button antenna with a reflective frequency selective surface(FSS) is proposed to reduce its back radiation. The proposed antenna is low in profile, circularly polarized and designed for Wi-Fi and WLAN applications. The radiating element is made of copper sheet, while a transparent acrylic fibre sheet is used as a substrate. The antenna is fed by a coaxial line, and the FSS layer is designed on jeans material. The patch type FSS with split ring shape has also been designed to operate in the Wi-Fi and WLAN frequency hand (5.250-5.850 GHz) with the centre frequency of 5.51 GHz. The FSS reduces hack radiation of the antenna by 4 dB. The antenna with FSS is fabricated, and a measured gain of 2.9dBi is obtained that matches well with the theoretical value. The antenna is miniaturized by around 61.15% by the slits. To achieve circular polarization characteristic Defected Ground Structure (DGS) slots etched at the ground plane of the triangular patch. The measured impedance bandwidth is 190MHz, and the 3dB axial-ratio (AR) bandwidth is 160MHz, respectively.
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| 3. |
- Mandal, Bappaditya, et al.
(författare)
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Low Profile Implantable Antenna for Fat Intra-Body Communication
- 2020
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Ingår i: 2020 14th European Conference on Antennas and Propagation (EuCAP). - 9788831299008 - 9781728137124
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Konferensbidrag (refereegranskat)abstract
- A flexible low profile biocompatible implantable antenna for fat intra-body communication is presented. This article gives an idea of fat channel communication at different distances. The antenna is designed on 0.25 mm thick low loss taconic material. The antenna is covered by 0.1 mm thick PDMS (Polydimethylsiloxane) to ensure biocompatibility with human tissue. A coplanar wave (CPW) microstrip line is used to feed the antenna. This antenna has been optimized to operate at the 2.4 GHz hand frequency in the human three -layer tissue model The simulation, as well as measurement, were done at a minimum distance of 10 mm, and the maximum distance of 70mm between of two implantable antennas. The measured path loss of the fat channel by using the proposed implantable antenna is estimated to be almost 2.5 dB per centimetre. The measured bandwidth of the proposed antenna found to be 660 MHz.
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| 4. |
- Nordebo, Sven, 1963-, et al.
(författare)
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On the optical theorem and optimal extinction, scattering and absorption in lossy media
- 2020
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Ingår i: 14th European Conference on Antennas and Propagation, EuCAP, 15 - 20 March 2020 Copenhagen, Denmark. - : IEEE. - 9788831299008 - 9781728137124 ; , s. 1-5
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Konferensbidrag (refereegranskat)abstract
- This paper reformulates and extends some recent analytical results concerning a new optical theorem and the associated physical bounds on absorption in lossy media. The analysis is valid for any linear scatterer (such as an antenna), consisting of arbitrary materials (bianisotropic, etc.) and arbitrary geometries, as long as the scatterer is circumscribed by a spherical volume embedded in a lossy background medium. The corresponding formulas are here reformulated and extended to encompass magnetic as well as dielectric background media. Explicit derivations, formulas and discussions are also given for the corresponding bounds on scattering and extinction. A numerical example concerning the optimal microwave absorption and scattering in atmospheric oxygen in the 60 GHz communication band is included to illustrate the theory.
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| 5. |
- Rangaiah, Pramod K. B., et al.
(författare)
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Clustering of Dielectric and Colour Profiles of an Ex-vivo Burnt Human Skin Sample
- 2020
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Ingår i: 14th European Conference on Antennas and Propagation (EuCAP). - 9788831299008 - 9781728137124
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Konferensbidrag (refereegranskat)abstract
- This work aims to introduce two techniques to characterize human burnt skin based on permittivity measurement and image processing. The first method is the sectorized measurement of permittivity (dielectric profiling, DEP) by using an open-end coaxial probe technique. The second method is the analysis of color variation in the burnt skin sample through image processing. Statistical analysis is done using tools such as Analysis of Variance (ANOVA), k-means, in order to classify, evaluate the data. As part of the classification, the experimental data are clustered into five groups based on the distribution of means (dielectric profiles) and centroids (color profiles). The color image is converted into a gray image and resized to a one-dimensional array. Furthermore, the analysis is done based on the intensity range, various centroid values, and silhouette analysis. The clustering results we obtained with these two methods can be used for comparing the dielectric characteristics with the color variation of the burnt human skin to assess burn degree.
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| 6. |
- Rangaiah, Pramod K. B., et al.
(författare)
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Design of constant width branch line directional coupler for the microwave sensing application
- 2020
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Ingår i: 14th European Conference on Antennas and Propagation (EuCAP). - 9788831299008 - 9781728137124
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Konferensbidrag (refereegranskat)abstract
- This paper investigates the design of directional branch-line coupler using constant width multiple sections of series and open microstrip line stubs. This device is operating at the center frequency of 2.45 GHz. The designed coupler is having good performance for the frequency band 2-3 GHz. The proposed design is compared with a typical branch line coupler and shows the improved performance. The design is simulated and fabricated on the Fibreglass-resin laminate (FR4) substrate of height 1.5 mm. The results of simulated and experimented circuits are discussed and analyzed. The circuit is measured using Combination Analyzer N9918A Field Fox Handheld Microwave Analyzer. The proposed topology is easy to design and fabricate with a planar microstrip line technology. The designed coupler shows the good results at 2.45GHz i.e. S 11 = -61.26 dB, S 21 = -45 dB, S 31 = -2dB and S 41 = -4.5dB. The main target of this work is to design a coupler to differentiate between transmitted and reflected signals in the split ring resonator (SRR) sensor for Bone Density Measurement Analysis (BDAS) system.
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| 7. |
- Arayeshnia, Amir, et al.
(författare)
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Miniaturized CPW-fed bowtie slot antenna for wearable biomedical applications
- 2020
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Ingår i: 2020 14th European Conference on Antennas and Propagation (EuCAP). - 9788831299008
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Konferensbidrag (refereegranskat)abstract
- A miniaturized, low -profile, flexible, and wearable ultra-wideband antenna for biomedical applications is proposed. The antenna is designed to operate in wearable conditions with the presence of multilayer biological tissues. A meandering technique is employed to reduce the electrical size of the antenna. The operational band of the proposed antenna is 0.5-4.5 GHz, while its dimensions are as small as 21x19.25x0.025 mm3. The antenna is simulated using a commercial full-wave simulator (CST Microwave Studio), fabricated on Polyethylene terephthalate (PET), and tested in realistic scenarios. The simulation and measurement results are in good compliance with each other.
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| 8. |
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| 9. |
- Bagheri, Alireza, et al.
(författare)
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Micro strip to Ridge Gap Waveguide Transition for 28 GHz Steerable Slot Array Antennas
- 2020
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Ingår i: 2020 14TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP 2020). - 2164-3342. - 9788831299008
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Konferensbidrag (refereegranskat)abstract
- In this paper three types of contactless vertical transitions from microstrip to double ridge waveguide are presented. The designs are compact in size and robust, with improved isolation by employing a pin structure, making them ideal for SG mmWave phased arrays. All transitions cover the 26.5 - 29.5 GHz band, their dimensions are less than half a wavelength in pitch and have insertion losses less than 0.6 dB. The three designs apply different matching strategies and offer a trade-off between bandwidth and PCB areas. Finally, the behavior within an array configuration is analyzed.
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| 10. |
- Capek, Miloslav, et al.
(författare)
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Fundamental Bounds for Volumetric Structures and Their Feasibility
- 2020
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Ingår i: 14th European Conference on Antennas and Propagation, EuCAP 2020. - 9788831299008
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Konferensbidrag (refereegranskat)abstract
- Fundamental bounds on antenna and scattering metrics are presented in this paper utilizing volumetric method of moments. This makes it possible to investigate scenarios not solvable with classical surface method of moments which assumes that good conductors as used. One practical example is the study of plasmonic devices whose operation relies on the interaction between material properties and radiation mechanisms. The implementation of the code is briefly summarized, including some implementation hints which allow for fast evaluation of necessary matrix operators. Two optimization problems are introduced and solved for scattering and antenna problems. Feasibility of the bounds will be investigated with topology optimization and the results will be presented during the conference.
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| 11. |
- Chen, Lei, et al.
(författare)
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A Method of Reducing Mutual Coupling for a Finite Array
- 2020
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Ingår i: 14th European Conference on Antennas and Propagation, EuCAP 2020. - 9788831299008
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Konferensbidrag (refereegranskat)abstract
- A method of reducing mutual coupling for a finite array with the characteristics of wideband and beam steering is presented in this paper. By adding an extra decoupling network, the mutual coupling can be efficiently suppressed for the antenna array. To verify the validity of the proposed method, a 1 x 8 millimeter-wave array antenna based on the gap waveguide technology is used in this work. The simulation results show that the active reflection coefficients are improved from 6.98 dB to -8.29dB, and the mutual coupling between adjacent elements is reduced to below -16.73 dB covering 20-33 GHz with the beam steering angle range of +/- 70 degrees.
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| 12. |
- Ebrahimizadeh, Javad, et al.
(författare)
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Pathloss Calculation for Fat-Intra Body Communication Using Poynting Vector Theory
- 2020
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Ingår i: 2020 14th European Conference on Antennas and Propagation (EuCAP). - 9788831299008
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Konferensbidrag (refereegranskat)abstract
- Recently, Fat-based Intra-Body Communication (Fat-IBC) has been proposed and studied in terms of its reliability in simulation and laboratory settings. We, in this work, try to address another important aspect of communication, namely pathloss, in the context of fat-IBC. The present paper provides numerical and experimental modeling of pathloss through the fat layer using the Poynting Vector theory and the Multi-layer dielectric Green's function (MGF). To calculate the pathloss based on Poynting vector theory, the electromagnetic field distribution through the involved media should be known. The present paper exploits the EM fields using MGF theory or commercial software CST Microwave Studio 2019. Finally, experimental measurement is done on ex-vivo tissue made of porcine skin, fat and muscle at the frequency range of 5 GHz - 6 GHz. The average measured pathloss is around 5.5 dB/cm which has good compliance with the theoretical Poynting vector pathloss estimation.
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| 13. |
- Lundgren, Johan, et al.
(författare)
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Measurement Characterization of Aperture Correction Technique for EMF
- 2020
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Ingår i: 14th European Conference on Antennas and Propagation, EuCAP 2020. - 9788831299008
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Konferensbidrag (refereegranskat)abstract
- Techniques for accurate, robust and efficient over-the-air testing for devices in the next generation communication system are important. This work aims at presenting the use of an aperture calibration technique, through which field values and power density values are reconstructed at an arbitrary plane in the near-field from a measurement of a separate plane for devices operating in 28-60 GHz. The technique calibrates for the probe interaction, and for the measured position, providing promising results. Power density levels is important for electromagnetic field (EMF) compliance assessment of 5G. In this work the technique is utilized to reconstruct the power densities, as close as λ/5, for three different radiating devices. The results are compared with simulations. An investigation into how the technique performs - for different frequencies, using synthetic input data, various grid sampling, noise and choice of numerical parameters is carried out, showing the regions of applicability.
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| 14. |
- Madannejad, Alireza, et al.
(författare)
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Reflectometry Enhancement by Saline Injection in Microwave-based Skin Burn Injury Diagnosis
- 2020
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Ingår i: 2020 14th European Conference on Antennas and Propagation (EuCAP). - 9788831299008
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Konferensbidrag (refereegranskat)abstract
- This paper provides a novel solution for increasing the difference between the contrast of permittivity of normal skin and burnt skin using injected saline. The paper makes use of injecting saline water into healthy tissue surrounding the burnt part to increase the conductivity contrast of the healthy tissue compared to the burnt area. After 5 minutes passed by injecting the saline, it will he distributed through the normal tissues while the burnt tissues are not able to absorb the saline. Therefore, the level of permittivity contrast between the healthy tissue and burnt tissue increase drastically which is useful for microwave noninvasive diagnosis.
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| 15. |
- Mattsson, Viktor, et al.
(författare)
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Neural Network Approach for Dielectric Characterization of Tissues in Microwave Frequencies using Coplanar Waveguide Transmission
- 2020
-
Ingår i: 2020 14th European Conference on Antennas and Propagation (EuCAP). - 9788831299008
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Konferensbidrag (refereegranskat)abstract
- This paper presents an extension to previous work, using neural networks to characterize materials in microwave frequencies, to extend the applicability of a deep learning model to be able to characterize the dielectric properties of biological tissues. A neural network model using convolutional and fully connected layers is designed to predict the permittivity and loss tangent using the scattering parameters from a coplanar waveguide transmission sensor. Simulated data from the sensor provide a large dataset, with a wide range of values for the permittivity and loss tangent, which is used to train and test the model. The trained network is validated by predicting the output parameters on the test set. Compared with previous work, by using convolutional layers the applicable parameter space is vastly extended while keeping satisfying levels of accuracy. A complete system with a trained network is proposed to be used in a lab or in clinics.
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| 16. |
- Petek, Martin, et al.
(författare)
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Fully-Metallic Rinehart-Luneburg Lens at 60 GHz
- 2020
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Ingår i: Proceedings 14th European Conference on Antennas and Propagation (EuCAP). - : Institute of Electrical and Electronics Engineers (IEEE). - 9788831299008
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Konferensbidrag (refereegranskat)abstract
- In this paper, we present the design of a Rinehart-Luneburg lens antenna operating from 56 to 62 GHz. At these high frequencies, dielectric materials introduce high losses, so fully-metallic solutions are typically preferred. The required refractive index of the Luneburg lens is realized by deforming the parallel plate waveguide following the concept of geodesic surfaces. Despite the high frequency, the achieved radiation efficiency is roughly 90%. Thirteen antenna ports are angularly placed along the contour of the lens to enable an electronical beam switching of +/-55 degrees with equally spaced steps and an interleaving dip loss of 6 dB.
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| 17. |
- Poordaraee, Mohammad, et al.
(författare)
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Chamber Array Antenna Layout for Compact OTA Measurements
- 2020
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Ingår i: 2020 14TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP 2020). - 2164-3342. - 9788831299008
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Konferensbidrag (refereegranskat)abstract
- An optimized irregular planar array antenna layout with uniform excitation of antenna elements is presented for Random-LOS OTA (Random Line-Of-Sight Over-The-Air) characterization setups. A plane wave is synthesized within a cylindrical 3D test zone at 2.7 GHz, which can be scaled to mmWave frequencies. The obtained thinned array achieves a 52% reduction of the number of elements and a 45% aperture size as compared to a uniform fully populated planar array with an inter-element distance of 0.93A, which is the optimum distance through [lambda/2, lambda] based on the presented cost function at this paper. The obtained maximum phase deviation and the maximum field amplitude deviation from the average field distribution in the 3D test zone of the proposed optimized chamber array antenna layout are approximately 6.4 and 3.9 dB, respectively. The numerical computation of the radiation pattern of a 10 x 10 element uniform planar array antenna as AUT (Antenna Under Test) placed within the test zone was performed too. Results show a rather good agreement between the radiation pattern to that obtained assuming far-field conditions.
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| 18. |
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| 19. |
- Sadeghi, Sajjad, et al.
(författare)
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A New Focused Hyperthermia is Based on Space-Frequency DORT
- 2020
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Ingår i: 2020 14th European Conference on Antennas and Propagation (EuCAP). - 9788831299008
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Konferensbidrag (refereegranskat)abstract
- Estimating the correct amplitude and phase of excitation for a phased array applicator in hyperthermia is crucial to focus the electromagnetic power only on the malignant biological tissue. The proposed algorithm is based on singular value decomposition to remove unwanted hot spots. Space-Frequency DORT method is used to separate the main scattering filed from second-order scattering. A complex voxel model is implemented for near to real scenario simulation.
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| 20. |
- Shaw, Tarakeswar, et al.
(författare)
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Wireless Power Transfer System Design in Reactive Near-Field for Implantable Devices
- 2020
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Ingår i: 2020 14th European Conference on Antennas and Propagation (EuCAP). - 9788831299008
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Konferensbidrag (refereegranskat)abstract
- In this paper, a wireless power transfer (WPT) system design for charging the bio-implantable devices in the reactive near-field of the antenna is presented. The proposed system is designed to operate in the industrial, scientific, and medical (ISM) of 2.40-2.48 GHz band. The WPT link is constructed with dual-ring slot antenna implanted in a single layer skin tissue model is used as a receiving (Rx) element and a simple patch antenna considered as transmitting (Tx) element. The patch antenna is designed to operate at the ISM of 2.45 GHz, whereas the dual-ring slot is used to obtain wideband characteristics that cover the entire ISM band. The strong mutual coupling between the Tx and Rx elements in the reactive near-field provide high power transfer efficiency for the proposed WPT system. Also, to reflect the real-life application scenario, the analysis of specific absorption rate (SAR) and misalignment between the Tx and Rx element is performed for the proposed system. Finally, the prototype of the Tx and Rx elements are fabricated and experimentally verified by using skin mimicking gel.
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| 21. |
- Siddiqui, Tauseef, et al.
(författare)
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Concept of Beam Steerable Transponder based on Load Modulation
- 2020
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Ingår i: 2020 14th European Conference on Antennas and Propagation (EuCAP). - 9788831299008 ; , s. 1-5
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Konferensbidrag (refereegranskat)abstract
- The concept of beam steering transponder based on load modulation is proposed to enhance the received power of backscattered communication devices. The transponder consists of antenna array elements of equal length operates at the Wi-Fi frequency band of 2.4GHz. By properly weighting the modulated signal in each port, the received power can be maximized in a particular direction depending on the direction of arrival (DoA) of the signal. The weighting is done differently for each direction. It provides up to approximately 11dB improvement in received power with weighting compared to backscatter communication with a single antenna transponder. The concept is studied theoretically and by simulations.
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| 22. |
- Wingren, Niklas, et al.
(författare)
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Analytical Modeling and Multiphysics Simulation of Acousto-Electromagnetic Interaction
- 2020
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Ingår i: 14th European Conference on Antennas and Propagation, EuCAP 2020. - 9788831299008
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Konferensbidrag (refereegranskat)abstract
- A model for interaction between acoustic and elec- tromagnetic waves based on photoelasticity is presented. A radar equation based on physical, geometric and system parameters is shown, as well as a condition for maximizing interaction (equivalent to the Bragg condition in acousto-optics). The photoelastic model is used to implement a multiphysics simulation of the problem. The Bragg condition is shown to hold for the simulated case. Additionally, simulations are used to show how a contrast in material properties in a small inclusion affects the interaction.
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| 23. |
- Ydreborg, Josef, et al.
(författare)
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Analysis of Compensation Methods and the Capability Boundary for Element Position Errors in Electrically Scanned Arrays
- 2020
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Ingår i: 14th European Conference on Antennas and Propagation, EuCAP 2020. - 9788831299008
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Konferensbidrag (refereegranskat)abstract
- Mechanical translational tolerances have negative effects on the radiation patterns in sensor and antenna arrays. Methods for restoring the radiation pattern of an array with element position errors to the designed one without the position errors have been investigated and the limits of their capabilities in different scenarios of real array configurations explored. A proof of concept has been established by manufacturing an intentionally erroneous antenna array and applying investigated compensation methods. Conclusion is that the possibilities of compensating for mechanical errors are greatly enhanced with increased digitalisation of the array antenna system. Analog systems may achieve a full compensation in a smaller solid angle, while digital systems can achieve a full compensation covering almost the half space.
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| 24. |
- Yousaf, Irfan Mehmood, et al.
(författare)
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Model simplification and validation of virtual prototypes for vehicular antenna design
- 2020
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Ingår i: 14th European Conference on Antennas and Propagation, EuCAP 2020. - 9788831299008
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Konferensbidrag (refereegranskat)abstract
- Wireless connectivity is becoming an important feature in cars, which together with recent developments in car design point to the need to accurately predict the performance of real antennas in simulation, to speed up the design cycle. However, it is challenging to accurately represent structurally complex real cars in simulation. This paper proposes a car model simplification approach for designing vehicular antennas, exemplified using three progressively simplified models of a hatchback car. For validation, a monopole and a PIFA operating at 800 MHz and 2.4 GHz, respectively, were mounted and simulated at two locations on these prototypes. The proposed scheme reduced the computational time to less than a third, while maintaining similar simulated antenna performance. Specifically, the antenna patterns of the simplest prototype and original one are correlated by 84% and 59% at 800 MHz and 2.4 GHz, respectively. Therefore, the proposed scheme is promising for real application.
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