Pub Date : 2015-11-01DOI: 10.1109/LAPC.2015.7366126
C. Christodoulou, D. Doyle, C. Woehrle, J. Costantine, Y. Tawk
Recent advances in reconfigurable RF components and systems have helped in the development of very complex reconfigurable antennas capable of radiating more than one pattern at different frequencies and polarizations. These types of antennas are becoming critical components in modern telecommunication systems from cognitive radio to cubesat communications.
{"title":"Reconfigurable antennas for cognitive radio and space applications","authors":"C. Christodoulou, D. Doyle, C. Woehrle, J. Costantine, Y. Tawk","doi":"10.1109/LAPC.2015.7366126","DOIUrl":"https://doi.org/10.1109/LAPC.2015.7366126","url":null,"abstract":"Recent advances in reconfigurable RF components and systems have helped in the development of very complex reconfigurable antennas capable of radiating more than one pattern at different frequencies and polarizations. These types of antennas are becoming critical components in modern telecommunication systems from cognitive radio to cubesat communications.","PeriodicalId":339610,"journal":{"name":"2015 Loughborough Antennas & Propagation Conference (LAPC)","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127571028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-11-01DOI: 10.1109/LAPC.2015.7366070
I. M. Masoud, Kenneth Lee Lee, J. Wild, M. Rao
This paper focuses on the application of a High Impedance Surface (HIS) to enhance the RF magnetic field (Hi) for a 1.5 Tesla Magnetic Resonance Imaging (MRI) system. The proposed structure is based on a miniaturized HIS using an interdigital capacitance approach. The surface utilizes a HIS between the Radio Frequency (RF) transmit coil and the MRI scanners RF shield which operates at 63.8MHz. The proposed system shows a higher Hi-field inside a homogeneous phantom as compared to a coil above an RF shield. By using this approach, the magnitude of Hi-field was improved by 40%.
{"title":"A high impedance surface for improving the radio frequency magnetic field for a 1.5 Tesla Magnetic Resonance system","authors":"I. M. Masoud, Kenneth Lee Lee, J. Wild, M. Rao","doi":"10.1109/LAPC.2015.7366070","DOIUrl":"https://doi.org/10.1109/LAPC.2015.7366070","url":null,"abstract":"This paper focuses on the application of a High Impedance Surface (HIS) to enhance the RF magnetic field (Hi) for a 1.5 Tesla Magnetic Resonance Imaging (MRI) system. The proposed structure is based on a miniaturized HIS using an interdigital capacitance approach. The surface utilizes a HIS between the Radio Frequency (RF) transmit coil and the MRI scanners RF shield which operates at 63.8MHz. The proposed system shows a higher Hi-field inside a homogeneous phantom as compared to a coil above an RF shield. By using this approach, the magnitude of Hi-field was improved by 40%.","PeriodicalId":339610,"journal":{"name":"2015 Loughborough Antennas & Propagation Conference (LAPC)","volume":"352 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124458538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-11-01DOI: 10.1109/LAPC.2015.7366082
Aris Tsolis, W. Whittow, A. Chauraya, A. Alexandridis, J. Vardaxoglou
A calibration measurement procedure applied on a cylindrical near field test site for wearable antenna measurements (on a liquid torso phantom at 2GHz) is presented. The proposed technique uses a 2mm thick conducting plate whose cross sectional dimensions are equal to that of the phantom to be used in the test. It is proved that this technique is effective and useful as a calibration of cylindrical near field wearable antenna measurements and removes the necessity of using the phantom.
{"title":"A calibration of a cylindrical near field test site appropriate for wearable antenna measurements on a liquid torso phantom at 2GHz","authors":"Aris Tsolis, W. Whittow, A. Chauraya, A. Alexandridis, J. Vardaxoglou","doi":"10.1109/LAPC.2015.7366082","DOIUrl":"https://doi.org/10.1109/LAPC.2015.7366082","url":null,"abstract":"A calibration measurement procedure applied on a cylindrical near field test site for wearable antenna measurements (on a liquid torso phantom at 2GHz) is presented. The proposed technique uses a 2mm thick conducting plate whose cross sectional dimensions are equal to that of the phantom to be used in the test. It is proved that this technique is effective and useful as a calibration of cylindrical near field wearable antenna measurements and removes the necessity of using the phantom.","PeriodicalId":339610,"journal":{"name":"2015 Loughborough Antennas & Propagation Conference (LAPC)","volume":"110 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121016194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-11-01DOI: 10.1109/LAPC.2015.7366128
J. Weng, Wuling Liu, Haonan Hu, Xiaoli Chu, Jie Zhang
Channel map has been widely used as an effective tool in network planning and deployment. However, there is a lack of mathematical formulation of the channel map as a tool for multiple-input multiple-output (MIMO) networks planning. In this work, we define and construct a MIMO channel map based on the extension of a mathematical formulation for the conventional single antenna channel map. We demonstrate the effectiveness of the constructed MIMO channel map in planning a distributed MIMO channel network through a numerical example. The results show that location optimisation in distributed MIMO systems gains significantly from an abstract formulation of the channel map.
{"title":"A mathematical formulation for MIMO channel map","authors":"J. Weng, Wuling Liu, Haonan Hu, Xiaoli Chu, Jie Zhang","doi":"10.1109/LAPC.2015.7366128","DOIUrl":"https://doi.org/10.1109/LAPC.2015.7366128","url":null,"abstract":"Channel map has been widely used as an effective tool in network planning and deployment. However, there is a lack of mathematical formulation of the channel map as a tool for multiple-input multiple-output (MIMO) networks planning. In this work, we define and construct a MIMO channel map based on the extension of a mathematical formulation for the conventional single antenna channel map. We demonstrate the effectiveness of the constructed MIMO channel map in planning a distributed MIMO channel network through a numerical example. The results show that location optimisation in distributed MIMO systems gains significantly from an abstract formulation of the channel map.","PeriodicalId":339610,"journal":{"name":"2015 Loughborough Antennas & Propagation Conference (LAPC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121319065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-11-01DOI: 10.1109/LAPC.2015.7366114
N. Neumann, M. Laabs, R. Hahnel, W. Benedix, S. Pache, Steffen Zietzschmann, P. Schneider, D. Plettemeier
Passive transponders based on surface acoustic waves (SAW) working at 2.4 GHz can be used in animal location systems inside stables where GPS fails. For that kind of systems, a steerable antenna is needed. Due to the environmental conditions inside a stable, a phased array antenna system providing electronic steering and avoiding moving parts is favorable. The design of such an active phased array antenna is explained. Based on the requirements from the location application, the antenna elements are developed first. Two candidates (patch and helix) are evaluated using simulations and measurements. To be flexible, a modularized approach (control unit, backplane carrying RF and antenna module) is chosen for the antenna system. First measurements of a line array are shown and discussed. Currently, the system is completed to form a 2D array which allows scanning in two directions.
{"title":"Active phased array antenna for animal location with passive surface acoustic wave based tags","authors":"N. Neumann, M. Laabs, R. Hahnel, W. Benedix, S. Pache, Steffen Zietzschmann, P. Schneider, D. Plettemeier","doi":"10.1109/LAPC.2015.7366114","DOIUrl":"https://doi.org/10.1109/LAPC.2015.7366114","url":null,"abstract":"Passive transponders based on surface acoustic waves (SAW) working at 2.4 GHz can be used in animal location systems inside stables where GPS fails. For that kind of systems, a steerable antenna is needed. Due to the environmental conditions inside a stable, a phased array antenna system providing electronic steering and avoiding moving parts is favorable. The design of such an active phased array antenna is explained. Based on the requirements from the location application, the antenna elements are developed first. Two candidates (patch and helix) are evaluated using simulations and measurements. To be flexible, a modularized approach (control unit, backplane carrying RF and antenna module) is chosen for the antenna system. First measurements of a line array are shown and discussed. Currently, the system is completed to form a 2D array which allows scanning in two directions.","PeriodicalId":339610,"journal":{"name":"2015 Loughborough Antennas & Propagation Conference (LAPC)","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122508430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-11-01DOI: 10.1109/LAPC.2015.7366046
Hengyi Zhou, A. Pal, A. Mehta
A compact planar antenna for modern multistandard smartphones is presented, which can operate in three bands: GSM (890-960 MHz), GPS (1500 MHz) and DCS (1710-1880 MHz). The proposed antenna is comprised of a feeding monopole and three radiating strips. The feeding monopole capacitively couple the RF excitation signal to the radiating strips. The length of these strips can control resonant frequencies of the antenna. The antenna is designed on a single-layered FR4 substrate. It has a total size of 37 mmx50 mmx 1.6 mm. Due to its compact structure the antenna can be directly printed on the circuit board to integrate with other parts of the circuits of a smartphone. The antenna possesses a reflection coefficient of better than -10 dB and nearly omnidirectional patterns over all the operating bands. Moreover, the directivity (>1.5 dB) and efficiencies (>70%) of the antenna are appropriate for modern smartphone applications. The effects of plastic housing, LCD screen and a human hand on the antenna performances are studied. The SAR (Specific Absorption Rate) values of the proposed antenna that absorbed into human head are also presented and it complies well with the standard of both the European Council in Europe and the Federal Communications Commission (FCC) in the United States.
{"title":"Low-SAR capacitively coupled compact multiband antenna for smartphones","authors":"Hengyi Zhou, A. Pal, A. Mehta","doi":"10.1109/LAPC.2015.7366046","DOIUrl":"https://doi.org/10.1109/LAPC.2015.7366046","url":null,"abstract":"A compact planar antenna for modern multistandard smartphones is presented, which can operate in three bands: GSM (890-960 MHz), GPS (1500 MHz) and DCS (1710-1880 MHz). The proposed antenna is comprised of a feeding monopole and three radiating strips. The feeding monopole capacitively couple the RF excitation signal to the radiating strips. The length of these strips can control resonant frequencies of the antenna. The antenna is designed on a single-layered FR4 substrate. It has a total size of 37 mmx50 mmx 1.6 mm. Due to its compact structure the antenna can be directly printed on the circuit board to integrate with other parts of the circuits of a smartphone. The antenna possesses a reflection coefficient of better than -10 dB and nearly omnidirectional patterns over all the operating bands. Moreover, the directivity (>1.5 dB) and efficiencies (>70%) of the antenna are appropriate for modern smartphone applications. The effects of plastic housing, LCD screen and a human hand on the antenna performances are studied. The SAR (Specific Absorption Rate) values of the proposed antenna that absorbed into human head are also presented and it complies well with the standard of both the European Council in Europe and the Federal Communications Commission (FCC) in the United States.","PeriodicalId":339610,"journal":{"name":"2015 Loughborough Antennas & Propagation Conference (LAPC)","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123188700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-11-01DOI: 10.1109/LAPC.2015.7366118
M. Rizwan, M. W. A. Khan, L. Sydanheimo, L. Ukkonen
This paper presents the performance evaluation of a circularly polarized wearable antenna on flexible Ethylene Propylene Diene Monomer (EPDM) foam substrate. EPDM is a rubber based material with high flexibility, good shock resistance and easy attachment to any curved surface. The designed antenna operates for Industrial, Scientific and Medical (ISM) band and Wireless Body Area Network (WBAN) applications at 2.45 GHz. Copper tape is used as the conductive material for the patch and the ground plane on 3 mm thick EPDM foam substrate having dielectric constant 1.23 and loss tangent 0.02. A rectangular slot along diagonal axis at the center of the circular patch is used for achieving circular polarization at 2.45 GHz. The measured operating frequency range of the antenna spans from 2.36 GHz to 2.48 GHz with the gain of 6.03 dB at 2.45 GHz. A set of comparative results of the antenna in free space and different body parts like arm and leg are compared to validate the operability of the antenna in real environment. This study provides new understanding about rubber material as substrate for flexible wearable antennas.
{"title":"Performance evaluation of circularly polarized patch antenna on flexible EPDM substrate near human body","authors":"M. Rizwan, M. W. A. Khan, L. Sydanheimo, L. Ukkonen","doi":"10.1109/LAPC.2015.7366118","DOIUrl":"https://doi.org/10.1109/LAPC.2015.7366118","url":null,"abstract":"This paper presents the performance evaluation of a circularly polarized wearable antenna on flexible Ethylene Propylene Diene Monomer (EPDM) foam substrate. EPDM is a rubber based material with high flexibility, good shock resistance and easy attachment to any curved surface. The designed antenna operates for Industrial, Scientific and Medical (ISM) band and Wireless Body Area Network (WBAN) applications at 2.45 GHz. Copper tape is used as the conductive material for the patch and the ground plane on 3 mm thick EPDM foam substrate having dielectric constant 1.23 and loss tangent 0.02. A rectangular slot along diagonal axis at the center of the circular patch is used for achieving circular polarization at 2.45 GHz. The measured operating frequency range of the antenna spans from 2.36 GHz to 2.48 GHz with the gain of 6.03 dB at 2.45 GHz. A set of comparative results of the antenna in free space and different body parts like arm and leg are compared to validate the operability of the antenna in real environment. This study provides new understanding about rubber material as substrate for flexible wearable antennas.","PeriodicalId":339610,"journal":{"name":"2015 Loughborough Antennas & Propagation Conference (LAPC)","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131443307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-11-01DOI: 10.1109/LAPC.2015.7366031
I. Munina, P. Turalchuk
The low loss design of input and output triplexers for high power application is presented. The input triplexer is realized as a microstrip structure, which consists of three third order filters and a star-junction. For the output triplexer design, it is suggested to use a combination of the microstrip star-junction and three interdigital cavity filters. Both structures provide a low insertion loss level and low cost manufacturing.
{"title":"Low loss triplexer design for high power application in radars","authors":"I. Munina, P. Turalchuk","doi":"10.1109/LAPC.2015.7366031","DOIUrl":"https://doi.org/10.1109/LAPC.2015.7366031","url":null,"abstract":"The low loss design of input and output triplexers for high power application is presented. The input triplexer is realized as a microstrip structure, which consists of three third order filters and a star-junction. For the output triplexer design, it is suggested to use a combination of the microstrip star-junction and three interdigital cavity filters. Both structures provide a low insertion loss level and low cost manufacturing.","PeriodicalId":339610,"journal":{"name":"2015 Loughborough Antennas & Propagation Conference (LAPC)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130621819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-11-01DOI: 10.1109/LAPC.2015.7366078
J. Slim, D. Heberling
The objective of this publication is to provide a conceptual and simulative study of a multi-channel hybrid coil system used primarily in magnetic resonance (MR) systems for imaging as a heat inducing system for RF hyperthermia applications. A 16-channels transverse electromagnetic (TEM) coil has been designed for dual purposes as a heat inducing device and as a transceiver for magnetic resonance imaging at 400 MHz (equivalent to the protons Larmor frequency at 9.4 Tesla). Full wave and circuit-wave co-simulations have been carried out. The point specific absorption rate (SAR) pattern is computed. The 3dB width of the formed `hotspot' is also evaluated and analyzed. Good matching (-28 dB) has been achieved at 400 MHz. The coupling between adjacent elements was -10.81 dB. The point SAR (with 1 W as accepted power) shows a clear sharp hotspot when the coils are used for heating. The 3dB width of the RF induced hotspot was 38 mm. The TEM RF coil used in high field MRI system, can be used as an RF hyperthermia applicator for simultaneous heating and imaging. The performance of the system shows a clear advantage compared to existing commercial system. No water bolus is required.
{"title":"Conceptual and simulative study of the transverse electromagnetic (TEM) RF coil as an RF hyperthermia applicator at 9.4 Tesla","authors":"J. Slim, D. Heberling","doi":"10.1109/LAPC.2015.7366078","DOIUrl":"https://doi.org/10.1109/LAPC.2015.7366078","url":null,"abstract":"The objective of this publication is to provide a conceptual and simulative study of a multi-channel hybrid coil system used primarily in magnetic resonance (MR) systems for imaging as a heat inducing system for RF hyperthermia applications. A 16-channels transverse electromagnetic (TEM) coil has been designed for dual purposes as a heat inducing device and as a transceiver for magnetic resonance imaging at 400 MHz (equivalent to the protons Larmor frequency at 9.4 Tesla). Full wave and circuit-wave co-simulations have been carried out. The point specific absorption rate (SAR) pattern is computed. The 3dB width of the formed `hotspot' is also evaluated and analyzed. Good matching (-28 dB) has been achieved at 400 MHz. The coupling between adjacent elements was -10.81 dB. The point SAR (with 1 W as accepted power) shows a clear sharp hotspot when the coils are used for heating. The 3dB width of the RF induced hotspot was 38 mm. The TEM RF coil used in high field MRI system, can be used as an RF hyperthermia applicator for simultaneous heating and imaging. The performance of the system shows a clear advantage compared to existing commercial system. No water bolus is required.","PeriodicalId":339610,"journal":{"name":"2015 Loughborough Antennas & Propagation Conference (LAPC)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123644412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-11-01DOI: 10.1109/LAPC.2015.7366117
A. Sabaawi, O. Al-Ani
In this paper, a study is conducted into using semiconductor materials in designing nanoantennas for solar energy harvesting. Different thin wire dipole nanoantennas made of carbon, heavily doped Ge and heavily doped Si are designed and their performance is compared with metal nanoantenna made of gold. Method of moments (MoM) is employed to numerically solve Hallen's integral equation in order to find the nanoantenna characteristics. The results show that carbon nanotube exhibit poor performance due to its low conductivity, whereas doping the semiconductor heavily can increase the conductivity and hence improve the efficiency.
{"title":"Heavily-doped semiconductor infrared antennas for solar energy harvesting","authors":"A. Sabaawi, O. Al-Ani","doi":"10.1109/LAPC.2015.7366117","DOIUrl":"https://doi.org/10.1109/LAPC.2015.7366117","url":null,"abstract":"In this paper, a study is conducted into using semiconductor materials in designing nanoantennas for solar energy harvesting. Different thin wire dipole nanoantennas made of carbon, heavily doped Ge and heavily doped Si are designed and their performance is compared with metal nanoantenna made of gold. Method of moments (MoM) is employed to numerically solve Hallen's integral equation in order to find the nanoantenna characteristics. The results show that carbon nanotube exhibit poor performance due to its low conductivity, whereas doping the semiconductor heavily can increase the conductivity and hence improve the efficiency.","PeriodicalId":339610,"journal":{"name":"2015 Loughborough Antennas & Propagation Conference (LAPC)","volume":"115 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124805742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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