This paper is focused on a wireless energy harvesting system using a rectifying antenna (rectenna). The proposed device consists of a wideband cross-dipole antenna, a microwave low-pass filter and a doubling rectifying circuit using Shottcky diodes as rectifying elements. Previously, a few of wideband rectennas have been investigated at 1.7 to 2.5 GHz. The originality of this paper is on the new wideband rectenna design which can harvest the ambient radio frequency (RF) power at 1.7 to 2.5 GHz. In this system, a new wideband cross dipole is designed and used to achieve the required bandwidth and duel-polarization. In addition, the voltage doubling rectifying circuit is optimized to achieve the best performance at power density levels < 200 μW/cm2 which are typical in urban environments. The characteristics of the proposed rectenna over the desired frequency range are investigated, and the integrated rectenna is simulated, made and tested for low input power densities from 5 to 200 μW/cm2. The simulation and measurement results of the rectenna are compared and a good agreement is achieved. The results demonstrate that the maximum rectenna conversion efficiency is nearly 57% around 1.7 GHz and over 20% over the wideband of interest for the incident power density of 120 μW/cm2. It is noted that the impedance matching is one of the main factors affecting the rectenna energy conversion efficiency. This new wideband rectenna has great potential to harvest wireless energy in GSM/3G/4G and ISM 2.4 GHz bands.
{"title":"An Investigation of Wideband Rectennas for Wireless Energy Harvesting","authors":"Jingwei Zhang, Yi Huang, P. Cao","doi":"10.4236/WET.2014.54012","DOIUrl":"https://doi.org/10.4236/WET.2014.54012","url":null,"abstract":"This paper is focused on a wireless energy harvesting system using a rectifying antenna (rectenna). The proposed device consists of a wideband cross-dipole antenna, a microwave low-pass filter and a doubling rectifying circuit using Shottcky diodes as rectifying elements. Previously, a few of wideband rectennas have been investigated at 1.7 to 2.5 GHz. The originality of this paper is on the new wideband rectenna design which can harvest the ambient radio frequency (RF) power at 1.7 to 2.5 GHz. In this system, a new wideband cross dipole is designed and used to achieve the required bandwidth and duel-polarization. In addition, the voltage doubling rectifying circuit is optimized to achieve the best performance at power density levels < 200 μW/cm2 which are typical in urban environments. The characteristics of the proposed rectenna over the desired frequency range are investigated, and the integrated rectenna is simulated, made and tested for low input power densities from 5 to 200 μW/cm2. The simulation and measurement results of the rectenna are compared and a good agreement is achieved. The results demonstrate that the maximum rectenna conversion efficiency is nearly 57% around 1.7 GHz and over 20% over the wideband of interest for the incident power density of 120 μW/cm2. It is noted that the impedance matching is one of the main factors affecting the rectenna energy conversion efficiency. This new wideband rectenna has great potential to harvest wireless energy in GSM/3G/4G and ISM 2.4 GHz bands.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":"05 1","pages":"107-116"},"PeriodicalIF":0.0,"publicationDate":"2014-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70839060","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}
M. Yamakawa, K. Shimamura, K. Komurasaki, H. Koizumi
Wireless power transfer (WPT) from a transmitter resonator on the ground to an electrically powered miniature heli-copter was attempted to demonstrate WPT using magnetic resonance coupling to an object moving in 3D space. The transmission efficiency was optimized by automatic impedance matching for different flight attitudes: a maximum flight altitude of 590 mm was achieved. Furthermore, an estimation method of transmission efficiency using only the properties on the transmitter side was proposed, with transmission power regulated as constant against the change in the coupling coefficient.
{"title":"Demonstration of Automatic Impedance-Matching and Constant Power Feeding to and Electric Helicopter via Magnetic Resonance Coupling","authors":"M. Yamakawa, K. Shimamura, K. Komurasaki, H. Koizumi","doi":"10.4236/WET.2014.53006","DOIUrl":"https://doi.org/10.4236/WET.2014.53006","url":null,"abstract":"Wireless power transfer (WPT) from a transmitter resonator on the ground \u0000to an electrically powered miniature heli-copter was attempted to demonstrate \u0000WPT using magnetic resonance coupling to an object moving in 3D space. The \u0000transmission efficiency was optimized by automatic impedance matching for \u0000different flight attitudes: a maximum flight altitude of 590 mm was achieved. \u0000Furthermore, an estimation method of transmission efficiency using only the \u0000properties on the transmitter side was proposed, with transmission power \u0000regulated as constant against the change in the coupling coefficient.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":"5 1","pages":"45-53"},"PeriodicalIF":0.0,"publicationDate":"2014-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70839293","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}
A low profile dual-band multiple-input-multiple-output (MIMO) antenna system is proposed. The proposed MIMO antenna consists of two low profile unbalanced fed inverted L antennas with parasitic elements to resonate at 2.45 GHz and 5 GHz. The structure is uncomplicated by locating two ultra low profile inverted L antennas on the finite conducting plane. The proposed MIMO antenna is numerically and experimentally analyzed. When the size of conducting plane is 55 mm by 55 mm and the height of antenna is 9 mm, the directive gain of 4.11 dBi and the S11 bandwidth of 5.71% are achieved for lower frequency of 2.45 GHz. At the upper frequency of 5 GHz, the directive gain of 8.22 dBi and the S11 bandwidth of 6% are obtained. The proposed antenna has good diversity gain, shown by the correlation coefficient becomes less than 0.005 at the frequency of 2.45 GHz and 5 GHz band when the distance between inverted L elements is 41 mm. A good agreement between calculated and measured results is obtained. The results show that the weak mutual coupling of the proposed antenna and this feature enables it to cover the required bandwidths for WLAN operation at the 2.4 GHz band and 5 GHz band.
{"title":"Dual Band MIMO Antenna Composed of Two Low Profile Unbalanced Fed Inverted L Antennas for Wireless Communications","authors":"E. Rohadi, M. Taguchi","doi":"10.4236/WET.2014.53007","DOIUrl":"https://doi.org/10.4236/WET.2014.53007","url":null,"abstract":"A low profile dual-band multiple-input-multiple-output (MIMO) antenna \u0000system is proposed. The proposed MIMO antenna consists of two low profile unbalanced \u0000fed inverted L antennas with parasitic elements to resonate at 2.45 GHz and 5 \u0000GHz. The structure is uncomplicated by locating two ultra low profile inverted L \u0000antennas on the finite conducting plane. The proposed MIMO antenna is numerically \u0000and experimentally analyzed. When the size of conducting plane is 55 mm by 55 \u0000mm and the height of antenna is 9 mm, the directive gain of \u00004.11 dBi and the S11 bandwidth of 5.71% are achieved for lower frequency of 2.45 GHz. At the upper frequency of 5 GHz, the directive gain of 8.22 dBi and \u0000the S11 bandwidth of 6% are obtained. The proposed antenna has good diversity gain, shown by the correlation \u0000coefficient becomes less than 0.005 at the frequency of 2.45 GHz and 5 GHz band \u0000when the distance between inverted L elements is 41 mm. A good agreement between calculated and \u0000measured results is obtained. The results show that the weak mutual coupling of \u0000the proposed antenna and this feature enables it to cover the required \u0000bandwidths for WLAN operation at the 2.4 GHz band and 5 GHz band.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":"5 1","pages":"54-61"},"PeriodicalIF":0.0,"publicationDate":"2014-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70839436","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}
L. Sakkila, A. Rivenq, C. Tatkeu, Y. Elhillali, J. Ghys
Radars and their applications were, for a long time, reserved to national defense, air security or weather service domains. For a few years, with the emergence of new technologies, radar applications have been developed and have become known in the civil domain. In particular, the arrival of UWB—Ultra-Wideband technology allows the design of compact and low-cost radars with multiple fields of application. In this paper, we focus on road applications, such as driving assistance with the objective of increasing safety and reducing accidents. In classical UWB radar systems, Gaussian and monocycle pulses are commonly used. In previous works, original waveforms based on orthogonal functions (Hermite and Gegenbauer) were proposed. These provide a good spatial resolution, suitable for radar detection. Another advantage of these waveforms is their multiple access capability, due to their orthogonality. The aim of the study presented in this article is to compare simulation and experimental results obtained, especially for short-range anticollision radar application, using these waveforms in one part and Gaussian and monocycle pulses in the other part. The originality of this paper relies on the new approach. Indeed, this comparison study using these waveforms has never been done before. Finally, some examples of real experiments in a real road environment with different waveforms are presented and analysed.
{"title":"Performances of Micropower UWB Radar Using Orthogonal Waveforms","authors":"L. Sakkila, A. Rivenq, C. Tatkeu, Y. Elhillali, J. Ghys","doi":"10.4236/WET.2014.53009","DOIUrl":"https://doi.org/10.4236/WET.2014.53009","url":null,"abstract":"Radars and their applications were, for a long time, reserved to \u0000national defense, air security or weather service domains. For a few years, \u0000with the emergence of new technologies, radar applications have been developed \u0000and have become known in the civil domain. In particular, the arrival of UWB—Ultra-Wideband technology allows the design of compact and low-cost \u0000radars with multiple fields of application. In this paper, we focus on road applications, \u0000such as driving assistance with the objective of increasing safety and reducing \u0000accidents. In classical UWB radar \u0000systems, Gaussian and monocycle pulses are commonly used. In previous works, original waveforms based on orthogonal \u0000functions (Hermite and Gegenbauer) were proposed. These provide a good spatial \u0000resolution, suitable for radar detection. Another advantage of these waveforms \u0000is their multiple access capability, due to their orthogonality. The aim of the \u0000study presented in this article is to compare simulation and experimental \u0000results obtained, especially for short-range anticollision radar application, \u0000using these waveforms in one part and Gaussian and monocycle pulses in the \u0000other part. The originality of this \u0000paper relies on the new approach. Indeed, this comparison study using these \u0000waveforms has never been done before. Finally, some examples of real \u0000experiments in a real road environment with different waveforms are presented \u0000and analysed.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":"05 1","pages":"74-87"},"PeriodicalIF":0.0,"publicationDate":"2014-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70839376","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}
In this paper, an antenna with reconfigurable band notches, for cognitive radio applications, is proposed. The antenna can be operated as ultra wideband, and is reconfigurable in terms of the ability to select a notched band in the SRR resonant frequency. The reconfigurable band notches are induced using a band-stop filter based on split-ring resonators (SRRs), and are controlled using electronic switches mounted over the SRRs. For this sake, the design of the band-stop filter is proposed. A prototype of filter is fabricated and measured. The incorporation of a band-stop filter, into a wideband antenna, is then looked into. The proposed antenna is designed and simulated using Ansoft HFSS. A prototype of the antenna is fabricated and measured. A good analogy between simulated and measured results is obtained.
{"title":"Design of Reconfigurable Band Notches Antenna for Cognitive Radio Applications","authors":"H. Lalj, H. Griguer, M. Drissi","doi":"10.4236/WET.2014.53011","DOIUrl":"https://doi.org/10.4236/WET.2014.53011","url":null,"abstract":"In this paper, an antenna with \u0000reconfigurable band notches, for cognitive radio applications, is proposed. The \u0000antenna can be operated as ultra wideband, and is reconfigurable in terms of \u0000the ability to select a notched band in the SRR resonant frequency. The reconfigurable \u0000band notches are induced using a band-stop filter based on split-ring \u0000resonators (SRRs), and are controlled using electronic switches mounted over \u0000the SRRs. For this sake, the design of the band-stop filter is proposed. A \u0000prototype of filter is fabricated and measured. The incorporation of a band-stop \u0000filter, into a wideband antenna, is then looked into. The proposed antenna is \u0000designed and simulated using Ansoft HFSS. A prototype of the antenna is \u0000fabricated and measured. A good analogy between simulated and measured results \u0000is obtained.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":"2014 1","pages":"99-105"},"PeriodicalIF":0.0,"publicationDate":"2014-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70839014","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}
This paper provides a review on the diversity techniques of IDMA (Interleave Division Multiple Access) technology in underwater wireless IDMA employs interleavers as the only means in order to distinguish the users. This paper provides a comprehensive study of diversity techniques in IDMA scheme to mitigate the fading issue. In this paper, we compare the different generation diversity techniques in IDMA scheme on computational complexity, bit error rate and memory requirement. Recent advancement in underwater communication is modulation techniques, multiplexing techniques and multiple access techniques. Underwater communication channel is characterized.
{"title":"Performance Evaluation of Diversity Techniques in IDMA Scheme for Next Generation (4G) in Underwater Wireless Communication","authors":"Prachi Tripathi, M. Shukla","doi":"10.4236/WET.2014.53010","DOIUrl":"https://doi.org/10.4236/WET.2014.53010","url":null,"abstract":"This paper provides a \u0000review on the diversity techniques of IDMA (Interleave Division Multiple \u0000Access) technology in underwater wireless IDMA employs interleavers as the only \u0000means in order to distinguish the users. This paper provides a comprehensive \u0000study of diversity techniques in IDMA scheme to mitigate the fading issue. In \u0000this paper, we compare the different generation diversity techniques in IDMA scheme \u0000on computational complexity, bit error rate and memory requirement. Recent \u0000advancement in underwater communication is modulation techniques, multiplexing \u0000techniques and multiple access techniques. Underwater communication channel is \u0000characterized.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":"5 1","pages":"88-98"},"PeriodicalIF":0.0,"publicationDate":"2014-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70839430","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}
Extending the lifetime of the wireless sensor networks (WSNs), where recharging sensors is not always possible, has been a major concern for researchers for the past decade. In this paper, we study the cooperation between nodes in wireless sensor networks in forwarding packets to others, and we propose a new collaboration technique which stimulates intermediate nodes to forward packets toward their destination. Some nodes show selfish behavior by denying the forwarding packets to other nodes in commercial networks in an effort to preserve their own energy. This paper applies a technique which is used to prolong the network lifetime, based on a node’s energy and trust value, and additionally incorporates fuzzy logic, which stimulates nodes to forward packets by rewarding cooperation. According to simulation results, the proposed approach surpasses the Nuglets (virtual currency) approach and the Reputation approach in network energy and thus prolongs the network lifetime. Additionally, our proposed approach demonstrates better results in the number of dropped packets, PDR and forwarded packets to neighboring nodes.
{"title":"An Efficient Billing Scheme for Trusted Nodes Using Fuzzy Logic in Wireless Sensor Networks","authors":"M. Shurman, Zaid A. Alomari, K. Mhaidat","doi":"10.4236/WET.2014.53008","DOIUrl":"https://doi.org/10.4236/WET.2014.53008","url":null,"abstract":"Extending the lifetime of the wireless sensor networks (WSNs), where recharging sensors is not always possible, has been a major concern for researchers for the past decade. In this paper, we study the cooperation between nodes in wireless sensor networks in forwarding packets to others, and we propose a new collaboration technique which stimulates intermediate nodes to forward packets toward their destination. Some nodes show selfish behavior by denying the forwarding packets to other nodes in commercial networks in an effort to preserve their own energy. This paper applies a technique which is used to prolong the network lifetime, based on a node’s energy and trust value, and additionally incorporates fuzzy logic, which stimulates nodes to forward packets by rewarding cooperation. According to simulation results, the proposed approach surpasses the Nuglets (virtual currency) approach and the Reputation approach in network energy and thus prolongs the network lifetime. Additionally, our proposed approach demonstrates better results in the number of dropped packets, PDR and forwarded packets to neighboring nodes.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":"05 1","pages":"62-73"},"PeriodicalIF":0.0,"publicationDate":"2014-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70839469","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}
In this paper, developed wireless portable infrared pyrometer with dual channel fiber optic is described. The pyrometer measures surface temperature in wide infrared spectral range of 2 - 25 um. A data processing algorithm based on the methods of synchronous detection providing accuracy
{"title":"Wireless Infrared Pyrometer with Fiber Optic: Construction and Processing Algorithms","authors":"I. Orlov, I. A. Nikiforov, A. Afanasjev","doi":"10.4236/WET.2014.52004","DOIUrl":"https://doi.org/10.4236/WET.2014.52004","url":null,"abstract":"In this paper, developed wireless portable infrared pyrometer with dual channel fiber optic is described. The pyrometer measures surface temperature in wide infrared spectral range of 2 - 25 um. A data processing algorithm based on the methods of synchronous detection providing accuracy","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":"5 1","pages":"25-33"},"PeriodicalIF":0.0,"publicationDate":"2014-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70839104","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}
Two ultra low profile inverted L antennas located on the square conducting plane are numerically and experimentally analyzed as the multiple input multiple output (MIMO) antenna system. When the size of conducting plane is 0.45 λ by 0.45 λ and the height of antenna is 0.03 λ, the directive gain of 4.12 dBi and the return loss bandwidth of 3.67% are achieved. The proposed antenna has good diversity gain shown by the correlation coefficient, and becomes less than 0.02 at the frequency of 2.45 GHz band when the distance between inverted L elements is 0.33 λ. The results show the weak mutual coupling of the proposed antenna and its performances are promising as MIMO antenna applications.
{"title":"Two Low Profile Unbalanced Fed Inverted L Elements on Square Conducting Plane for MIMO Applications","authors":"E. Rohadi, M. Taguchi","doi":"10.4236/WET.2014.52005","DOIUrl":"https://doi.org/10.4236/WET.2014.52005","url":null,"abstract":"Two ultra low profile inverted L antennas located on the square conducting plane are numerically and experimentally analyzed as the multiple input multiple output (MIMO) antenna system. When the size of conducting plane is 0.45 λ by 0.45 λ and the height of antenna is 0.03 λ, the directive gain of 4.12 dBi and the return loss bandwidth of 3.67% are achieved. The proposed antenna has good diversity gain shown by the correlation coefficient, and becomes less than 0.02 at the frequency of 2.45 GHz band when the distance between inverted L elements is 0.33 λ. The results show the weak mutual coupling of the proposed antenna and its performances are promising as MIMO antenna applications.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":"5 1","pages":"34-43"},"PeriodicalIF":0.0,"publicationDate":"2014-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70839182","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}
M. Yamakawa, Y. Mizuno, Jun Ishida, K. Komurasaki, H. Koizumi
In this paper, a wireless power transmission system using magnetic resonance coupling was proposed and demonstrated for supplying power at high efficiency to electrical devices in a space enclosed by metal walls. This is applicable to power supply to electrical sensors or devices working in the area surrounded by metal walls. Proposed magnetic resonance coupling system is driven at a resonance frequency of 50 Hz, which is selected to avoid eddy current loss on the surrounding metals. Firstly, resonator designs and its performance limitation were described. Secondly, the equivalent circuits and theoretical transmission efficiency were presented. Finally, power transmission was experimentally demonstrated and transmission efficiency was measured in some conceivable situations. As a result, electric power of 3 W was supplied to LEDs over a stainless steel wall. When the stainless steel wall thickness was 10 mm, transmission efficiency of approximately 40% was achieved over the transmission distance of 12 cm. Moreover, in the demonstration of transmission through a metal pipe, 1.2 W of power was transmitted to LEDs in a 10 mm thick metal pipe.
{"title":"Wireless Power Transmission into a Space Enclosed by Metal Walls Using Magnetic Resonance Coupling","authors":"M. Yamakawa, Y. Mizuno, Jun Ishida, K. Komurasaki, H. Koizumi","doi":"10.4236/WET.2014.51003","DOIUrl":"https://doi.org/10.4236/WET.2014.51003","url":null,"abstract":"In this paper, a wireless power transmission system using magnetic resonance coupling was proposed and demonstrated for supplying power at high efficiency to electrical devices in a space enclosed by metal walls. This is applicable to power supply to electrical sensors or devices working in the area surrounded by metal walls. Proposed magnetic resonance coupling system is driven at a resonance frequency of 50 Hz, which is selected to avoid eddy current loss on the surrounding metals. Firstly, resonator designs and its performance limitation were described. Secondly, the equivalent circuits and theoretical transmission efficiency were presented. Finally, power transmission was experimentally demonstrated and transmission efficiency was measured in some conceivable situations. As a result, electric power of 3 W was supplied to LEDs over a stainless steel wall. When the stainless steel wall thickness was 10 mm, transmission efficiency of approximately 40% was achieved over the transmission distance of 12 cm. Moreover, in the demonstration of transmission through a metal pipe, 1.2 W of power was transmitted to LEDs in a 10 mm thick metal pipe.","PeriodicalId":68067,"journal":{"name":"无线工程与技术(英文)","volume":"5 1","pages":"19-24"},"PeriodicalIF":0.0,"publicationDate":"2014-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70838724","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}