Pub Date : 2017-11-13DOI: 10.23919/URSIGASS.2017.8105240
K. Mistry, P. Lazaridis, I. Glover, V. Holmes, F. Khan, Q. Ahmed, Z. Zaharis, T. Xenos
Log-periodic antenna is a special antenna type utilized with great success in many broadband applications due to its ability to achieve nearly constant gain over a wide frequency range. Such antennas are extensively used in electromagnetic compatibility measurements, spectrum monitoring and TV reception. In this study, a log-periodic dipole array is measured, simulated, and then optimized in the 470–860 MHz frequency band. Two simulations of the antenna are initially performed in time and frequency domain respectively. The comparison between these simulations is presented to ensure accurate modelling of the antenna. The practically measured net gain is in good agreement with the simulated net gain. The antenna is then optimized to concurrently improve voltage standing wave ration, net gain and front-to-back ratio. The optimization process has been implemented by using various algorithms included in CST Microwave Studio, such as Trusted Region Framework, Nelder Mead Simplex algorithm, Classic Powell and Covariance Matrix Adaptation Evolutionary Strategy (CMA-ES). The Trusted Region Framework seems to have the best performance in sufficiently optimizing all predefined goals specified for the antenna.
{"title":"Measurement, simulation and optimization of wideband log-periodic antennas","authors":"K. Mistry, P. Lazaridis, I. Glover, V. Holmes, F. Khan, Q. Ahmed, Z. Zaharis, T. Xenos","doi":"10.23919/URSIGASS.2017.8105240","DOIUrl":"https://doi.org/10.23919/URSIGASS.2017.8105240","url":null,"abstract":"Log-periodic antenna is a special antenna type utilized with great success in many broadband applications due to its ability to achieve nearly constant gain over a wide frequency range. Such antennas are extensively used in electromagnetic compatibility measurements, spectrum monitoring and TV reception. In this study, a log-periodic dipole array is measured, simulated, and then optimized in the 470–860 MHz frequency band. Two simulations of the antenna are initially performed in time and frequency domain respectively. The comparison between these simulations is presented to ensure accurate modelling of the antenna. The practically measured net gain is in good agreement with the simulated net gain. The antenna is then optimized to concurrently improve voltage standing wave ration, net gain and front-to-back ratio. The optimization process has been implemented by using various algorithms included in CST Microwave Studio, such as Trusted Region Framework, Nelder Mead Simplex algorithm, Classic Powell and Covariance Matrix Adaptation Evolutionary Strategy (CMA-ES). The Trusted Region Framework seems to have the best performance in sufficiently optimizing all predefined goals specified for the antenna.","PeriodicalId":377869,"journal":{"name":"2017 XXXIInd General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121071010","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 : 2017-11-13DOI: 10.23919/URSIGASS.2017.8105406
R. Haigh, D. Upton, P. Mather, M. Sibley
The advancement and use of silicon photo multiplier (SiPM) technology has enabled portable devices for applications such as scintillation detection to be developed. The proposed analogue to digital converter (ADC) architecture and field programmable gate array (FPGA) system configuration advances on analogue signal processing methods, traditionally employed for gamma isotope identification applications. This is achieved by high speed sampling of SiPM output signals and real-time FPGA processing, whilst consuming low power, thus extending device operation times. Results demonstrate 7-bit peak capture accuracy of an 8 μs scintillation event, using a 25 MHz ADC sample rate.
{"title":"Low power embedded processing of scintillation events with silicon photo multipliers","authors":"R. Haigh, D. Upton, P. Mather, M. Sibley","doi":"10.23919/URSIGASS.2017.8105406","DOIUrl":"https://doi.org/10.23919/URSIGASS.2017.8105406","url":null,"abstract":"The advancement and use of silicon photo multiplier (SiPM) technology has enabled portable devices for applications such as scintillation detection to be developed. The proposed analogue to digital converter (ADC) architecture and field programmable gate array (FPGA) system configuration advances on analogue signal processing methods, traditionally employed for gamma isotope identification applications. This is achieved by high speed sampling of SiPM output signals and real-time FPGA processing, whilst consuming low power, thus extending device operation times. Results demonstrate 7-bit peak capture accuracy of an 8 μs scintillation event, using a 25 MHz ADC sample rate.","PeriodicalId":377869,"journal":{"name":"2017 XXXIInd General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130378456","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 : 2017-11-13DOI: 10.23919/URSIGASS.2017.8104969
A. Jaber, P. Lazaridis, B. Saeed, P. Mather, M. F. Vieira, R. Atkinson, C. Tachtatzis, E. Iorkyase, M. Judd, I. Glover
The work reported in this paper addresses the calibration of four types of partial discharge (PD) emulator required for the development of a PD Wireless Sensor Network (WSN). Three partial discharge (PD) emulators have been constructed: a floating-electrode emulator, and two internal PD emulators. Both DC and AC HV power supplies are used to initiate PD which is measured using concurrent free-space radiometry (FSR) and a galvanic contact method based on the IEC 60270 standard. A new method of estimating absolute PD activity level from a radiometric measurement is proposed.
{"title":"Diagnostic potential of free-space radiometric partial discharge measurements","authors":"A. Jaber, P. Lazaridis, B. Saeed, P. Mather, M. F. Vieira, R. Atkinson, C. Tachtatzis, E. Iorkyase, M. Judd, I. Glover","doi":"10.23919/URSIGASS.2017.8104969","DOIUrl":"https://doi.org/10.23919/URSIGASS.2017.8104969","url":null,"abstract":"The work reported in this paper addresses the calibration of four types of partial discharge (PD) emulator required for the development of a PD Wireless Sensor Network (WSN). Three partial discharge (PD) emulators have been constructed: a floating-electrode emulator, and two internal PD emulators. Both DC and AC HV power supplies are used to initiate PD which is measured using concurrent free-space radiometry (FSR) and a galvanic contact method based on the IEC 60270 standard. A new method of estimating absolute PD activity level from a radiometric measurement is proposed.","PeriodicalId":377869,"journal":{"name":"2017 XXXIInd General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127976304","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 : 2017-11-13DOI: 10.23919/URSIGASS.2017.8105201
I. Setiawan, F. Leferink
Conducted interference is rapidly increasing due to the widespread use of power electronics. This is causing an increase of interference cases, and is limiting the possibility of using the mains wiring for low-frequency power line communication, such as the mains communication system between smart meters. Increasing the mains communication signal amplitude would result in more interference, while decreasing the emission level of the power electronics via filtering would also decrease the wanted communication signal amplitude. By using low-cost digitisers for measurements of conducted emission in time domain and fast fourier transform to the frequency domain time-frequency spectrograms can be generated. These show that conducted interference is mainly cyclo-stationary and at fized frequencies, showing open areas, or slots, in time-as well as frequency-domain. These slots can be used for the mains communication. This requires smarter EMC standards, and not in frequency domain only.
{"title":"Time-frequency diversity measurements in power systems","authors":"I. Setiawan, F. Leferink","doi":"10.23919/URSIGASS.2017.8105201","DOIUrl":"https://doi.org/10.23919/URSIGASS.2017.8105201","url":null,"abstract":"Conducted interference is rapidly increasing due to the widespread use of power electronics. This is causing an increase of interference cases, and is limiting the possibility of using the mains wiring for low-frequency power line communication, such as the mains communication system between smart meters. Increasing the mains communication signal amplitude would result in more interference, while decreasing the emission level of the power electronics via filtering would also decrease the wanted communication signal amplitude. By using low-cost digitisers for measurements of conducted emission in time domain and fast fourier transform to the frequency domain time-frequency spectrograms can be generated. These show that conducted interference is mainly cyclo-stationary and at fized frequencies, showing open areas, or slots, in time-as well as frequency-domain. These slots can be used for the mains communication. This requires smarter EMC standards, and not in frequency domain only.","PeriodicalId":377869,"journal":{"name":"2017 XXXIInd General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127502453","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 : 2017-11-13DOI: 10.23919/URSIGASS.2017.8105136
Mostafa H. Ahfayd, M. Sibley, P. Mather, P. Lazaridis
In this paper, the performance of a visible light communication (VLC) system based on offset pulse position modulation (Offset-PPM) has been demonstrated using a commercial high power white single LED (30 W) and the new coding scheme. Data at a speed of 11 Mbps has been successfully transmitted over a distance of 1 m with zero bit error rate (BER), and 18 Mbps with 1.15 × 10−6 of BER through the simplest transceiver circuits.
{"title":"Visible light communication based on offset pulse position modulation (Offset-PPM) using high power LED","authors":"Mostafa H. Ahfayd, M. Sibley, P. Mather, P. Lazaridis","doi":"10.23919/URSIGASS.2017.8105136","DOIUrl":"https://doi.org/10.23919/URSIGASS.2017.8105136","url":null,"abstract":"In this paper, the performance of a visible light communication (VLC) system based on offset pulse position modulation (Offset-PPM) has been demonstrated using a commercial high power white single LED (30 W) and the new coding scheme. Data at a speed of 11 Mbps has been successfully transmitted over a distance of 1 m with zero bit error rate (BER), and 18 Mbps with 1.15 × 10−6 of BER through the simplest transceiver circuits.","PeriodicalId":377869,"journal":{"name":"2017 XXXIInd General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116599145","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 : 2017-11-10DOI: 10.23919/URSIGASS.2017.8105232
J. Córcoles, E. Zastrow, N. Kuster
This paper presents a strategy, based on optimization techniques, to design the radiofrequency excitations in a multiple-channel magnetic resonance system operating at 128 MHz, in order to enhance radiofrequency magnetic field 1 homogeneity while reducing the estimated mean induced power deposited (Pind) by an active implantable medical device. Numerical examples on an implanted patient with a generic implant in different locations of a deep brain stimulator undergoing head/brain imaging are presented. Results from these examples show that more degrees of freedom (number of channels) can provide reduced induced deposited power while maintaining a high homogeneity.
{"title":"Optimization-based strategy in multiple-channel magnetic resonance systems operating at 128 MHz to reduce radiofrequency heating induced by active implantable medical devices","authors":"J. Córcoles, E. Zastrow, N. Kuster","doi":"10.23919/URSIGASS.2017.8105232","DOIUrl":"https://doi.org/10.23919/URSIGASS.2017.8105232","url":null,"abstract":"This paper presents a strategy, based on optimization techniques, to design the radiofrequency excitations in a multiple-channel magnetic resonance system operating at 128 MHz, in order to enhance radiofrequency magnetic field 1 homogeneity while reducing the estimated mean induced power deposited (Pind) by an active implantable medical device. Numerical examples on an implanted patient with a generic implant in different locations of a deep brain stimulator undergoing head/brain imaging are presented. Results from these examples show that more degrees of freedom (number of channels) can provide reduced induced deposited power while maintaining a high homogeneity.","PeriodicalId":377869,"journal":{"name":"2017 XXXIInd General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS)","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126410462","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 : 2017-08-20DOI: 10.23919/URSIGASS.2017.8105408
Y. Louét, V. Savaux, A. Kountouris, C. Moy
This paper shows that sub-sampling of signals can help in reducing the amount of data to be processed and stored when time and frequency sparsity is considered. The context is the one of the Internet of Things (IoT) for which a huge quantity of users (i.e. objects) communicate with very few time and frequency accesses. Taking advantage of the occupancy theory of probabilities, we propose a theoretical model for such communications and we show that the sampling frequency of signals can be significantly reduced under these assumptions.
{"title":"Sub-sampling of channels with time and frequency sparsity access","authors":"Y. Louét, V. Savaux, A. Kountouris, C. Moy","doi":"10.23919/URSIGASS.2017.8105408","DOIUrl":"https://doi.org/10.23919/URSIGASS.2017.8105408","url":null,"abstract":"This paper shows that sub-sampling of signals can help in reducing the amount of data to be processed and stored when time and frequency sparsity is considered. The context is the one of the Internet of Things (IoT) for which a huge quantity of users (i.e. objects) communicate with very few time and frequency accesses. Taking advantage of the occupancy theory of probabilities, we propose a theoretical model for such communications and we show that the sampling frequency of signals can be significantly reduced under these assumptions.","PeriodicalId":377869,"journal":{"name":"2017 XXXIInd General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS)","volume":"147 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115984892","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 : 2017-08-20DOI: 10.23919/URSIGASS.2017.8105386
Mouna Ben Mabrouk, Marwa Chafii, Y. Louët, F. Bader
To meet 5G networks challenges in terms of high data rates and spectral efficiency, one solution might be using multicarrier modulations (MCM)s. However, using MCMs is synonymous with low energy efficiency due to their high peak-to-average power ratio (PAPR). Indeed, high PAPR signals drive power amplifiers to operate most of the time in the linear zone. This latter corresponds to low power efficiency. This leads to a trade-off between spectral and energy efficiency. For this reason, PAPR reduction techniques have been highly addressed in literature. In this work, this trade-off is addressed differently: a necessary condition to achieve better PAPR performance than orthogonal frequency division multiplexing (OFDM) is established. This theoretical condition is verified by simulation results carried on Fourier-based and wavelet-based MCMs. The established condition classifies the MCMs into three categories regarding the PAPR: same as, higher than and lower than the OFDM PAPR level.
{"title":"Low-PAPR condition for 5G-candidate waveforms","authors":"Mouna Ben Mabrouk, Marwa Chafii, Y. Louët, F. Bader","doi":"10.23919/URSIGASS.2017.8105386","DOIUrl":"https://doi.org/10.23919/URSIGASS.2017.8105386","url":null,"abstract":"To meet 5G networks challenges in terms of high data rates and spectral efficiency, one solution might be using multicarrier modulations (MCM)s. However, using MCMs is synonymous with low energy efficiency due to their high peak-to-average power ratio (PAPR). Indeed, high PAPR signals drive power amplifiers to operate most of the time in the linear zone. This latter corresponds to low power efficiency. This leads to a trade-off between spectral and energy efficiency. For this reason, PAPR reduction techniques have been highly addressed in literature. In this work, this trade-off is addressed differently: a necessary condition to achieve better PAPR performance than orthogonal frequency division multiplexing (OFDM) is established. This theoretical condition is verified by simulation results carried on Fourier-based and wavelet-based MCMs. The established condition classifies the MCMs into three categories regarding the PAPR: same as, higher than and lower than the OFDM PAPR level.","PeriodicalId":377869,"journal":{"name":"2017 XXXIInd General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS)","volume":"238 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115180517","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 : 2017-08-20DOI: 10.23919/URSIGASS.2017.8105370
Yifan Zhou, Y. Louét, Honggang Zhang
This paper will discuss the distributed caching strategies in clustered heterogeneous cellular networks. Basically, there are two obstacles to accomplish the caching policy in the wireless access networks, i.e., the limited storage capacity of small cells and the too small coverage area of each base station to imply content aggregation effect. Traditionally, the existing caching strategies only concern the local requests within one base station coverage, which neglects the clustered characteristics of network infrastructure and user traffic demand. In this paper, we consider a two-tier clustered cellular networks, within which small cells can exchange content to fulfill each user request. Intuitively, this cooperation between base stations increases the service capacity of clustered cellular networks as testified in our numerical simulation.
{"title":"Probabilistic caching strategy in collaborative small cell networks","authors":"Yifan Zhou, Y. Louét, Honggang Zhang","doi":"10.23919/URSIGASS.2017.8105370","DOIUrl":"https://doi.org/10.23919/URSIGASS.2017.8105370","url":null,"abstract":"This paper will discuss the distributed caching strategies in clustered heterogeneous cellular networks. Basically, there are two obstacles to accomplish the caching policy in the wireless access networks, i.e., the limited storage capacity of small cells and the too small coverage area of each base station to imply content aggregation effect. Traditionally, the existing caching strategies only concern the local requests within one base station coverage, which neglects the clustered characteristics of network infrastructure and user traffic demand. In this paper, we consider a two-tier clustered cellular networks, within which small cells can exchange content to fulfill each user request. Intuitively, this cooperation between base stations increases the service capacity of clustered cellular networks as testified in our numerical simulation.","PeriodicalId":377869,"journal":{"name":"2017 XXXIInd General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS)","volume":"368 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134327135","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 : 2017-08-19DOI: 10.23919/URSIGASS.2017.8105244
M. Diop, E. Clavel, H. Cheaito, C. Vollaire, E. Vialardi
Electronic Equipment designed to be loaded onto an aircraft must be certified in accordance with established EMC standards. This paper is focused on section 20 of RTCA-DO160 which refers to conducted susceptibility in aeronautics. Since equipment can succeed or not in qualification test, aim is to be able to predict these levels of disturbance for limiting costs and time design. Moreover, aircraft manufacturers are mostly looking for precise answers about the sensitivity and reproducibility of these tests. In this sense, a 2D model of probe coupling to wires is developed in this work.
{"title":"2D modeling of bulk current injection probe and validation with measurements","authors":"M. Diop, E. Clavel, H. Cheaito, C. Vollaire, E. Vialardi","doi":"10.23919/URSIGASS.2017.8105244","DOIUrl":"https://doi.org/10.23919/URSIGASS.2017.8105244","url":null,"abstract":"Electronic Equipment designed to be loaded onto an aircraft must be certified in accordance with established EMC standards. This paper is focused on section 20 of RTCA-DO160 which refers to conducted susceptibility in aeronautics. Since equipment can succeed or not in qualification test, aim is to be able to predict these levels of disturbance for limiting costs and time design. Moreover, aircraft manufacturers are mostly looking for precise answers about the sensitivity and reproducibility of these tests. In this sense, a 2D model of probe coupling to wires is developed in this work.","PeriodicalId":377869,"journal":{"name":"2017 XXXIInd General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS)","volume":"10 7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126958933","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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