With the help of in-body antennas,the wireless communication among the implantable medical devices(IMDs)and exterior monitoring equipment,the telemetry system has brought us many benefits.Thus,a very thin-profile circ...With the help of in-body antennas,the wireless communication among the implantable medical devices(IMDs)and exterior monitoring equipment,the telemetry system has brought us many benefits.Thus,a very thin-profile circularly polarized(CP)in-body antenna,functioning in ISM band at 2.45 GHz,is proposed.A tapered coplanar waveguide(CPW)method is used to excite the antenna.The radiator contains a pentagonal shape with five horizontal slits inside to obtain a circular polarization behavior.A bendable Roger Duroid RT5880 material(εr=2.2,tanδ=0.0009)with a typical 0.25 mm-thickness is used as a substrate.The proposed antenna has a total volume of 21×13×0.25 mm3.The antenna covers up a bandwidth of 2.38 to 2.53 GHz(150 MHz)in vacuum,while in skin tissue it covers 1.56 to 2.72 GHz(1.16 GHz)and in the muscle tissue covers 2.16 to 3.17 GHz(1.01 GHz).GHz).The flexion analysis in the x and y axes was also performed in simulation as the proposed antenna works with a wider bandwidth in the skin and muscle tissue.The simulation and the curved antenna measurements turned out to be in good agreement.The impedance bandwidth of−10 dB and the axis ratio bandwidth of 3 dB(AR)are measured on the skin and imitative gel of the pig at 27.78%and 35.5%,13.5%and 4.9%,respectively,at a frequency of 2.45 GHz.The simulations revealed that the specific absorption rate(SAR)in the skin is 0.634 and 0.914 W/kg in muscle on 1g-tissue.The recommended SAR values are below the limits set by the federal communications commission(FCC).Finally,the proposed low-profile implantable antenna has achieved very compact size,flexibility,lower SAR values,high gain,higher impedance and axis ratio bandwidths in the skin and muscle tissues of the human body.This antenna is smaller in size and a good applicant for application in medical implants.展开更多
This work presents a new bendable antenna for worldwide interoperability for microwave access (WiMAX) wireless communication systems. These antennas, transparent and flexible, will be easily integrated into various md...This work presents a new bendable antenna for worldwide interoperability for microwave access (WiMAX) wireless communication systems. These antennas, transparent and flexible, will be easily integrated into various mdia and in particular OLED lighting which could be part of the public lighting network of tomorrow as well as on all display media. The integration of these antennas as close as possible to the end-user is a possible solution to reduce the energy consumption which goes hand in hand with the increase in the data rate. This kind of new antenna, designed to be integrated in organic light-emitting diode (OLED), was modeled from a transparent VeilShieldTM conductive fabric and was placed on a 100% polyester substrate with a thickness of 1.5 mm and a loss tangent of 0.02. We have tested and evaluated the characteristic parameters of our antenna, namely the reflection coefficient, the radiation pattern and the gain, to find out the performance of our proposed design. The performance of the transparent conductive fabric integrated in the 100% polyester substrate is tested for the application of flexible antenna operating at 3.5 GHz with a gain value of 5.38 dB. We have integrated this proposed new antenna with the OLED light source containing four layers of different materials and electrical properties: aluminum cathode layer, polymer layer, indium tin oxide (ITO) anode layer and glass substrate layer. After integration, the resonant frequency shifted to 3.52 GHz with a gain value of 4.61 dB. In addition, we also tested the concave bending on the reflection coefficient of the proposed flexible antenna taking into account the different bending angles. This work demonstrates the possibility of integrating these unconventional materials used for the proposed antenna within the OLED despite weak effects on the resonant frequency and the gain of the proposed antenna after integration.展开更多
The miniaturization and endurance of wearable devices have been the research direction for a long time.With the development of nanotechnology and the emergence of microelectronics products,people have explored many ne...The miniaturization and endurance of wearable devices have been the research direction for a long time.With the development of nanotechnology and the emergence of microelectronics products,people have explored many new strategies that may be applied to wearable devices.In this overview,we will summarize the recent research of wearable devices in these two directions,and summarize some available related technologies.展开更多
文摘With the help of in-body antennas,the wireless communication among the implantable medical devices(IMDs)and exterior monitoring equipment,the telemetry system has brought us many benefits.Thus,a very thin-profile circularly polarized(CP)in-body antenna,functioning in ISM band at 2.45 GHz,is proposed.A tapered coplanar waveguide(CPW)method is used to excite the antenna.The radiator contains a pentagonal shape with five horizontal slits inside to obtain a circular polarization behavior.A bendable Roger Duroid RT5880 material(εr=2.2,tanδ=0.0009)with a typical 0.25 mm-thickness is used as a substrate.The proposed antenna has a total volume of 21×13×0.25 mm3.The antenna covers up a bandwidth of 2.38 to 2.53 GHz(150 MHz)in vacuum,while in skin tissue it covers 1.56 to 2.72 GHz(1.16 GHz)and in the muscle tissue covers 2.16 to 3.17 GHz(1.01 GHz).GHz).The flexion analysis in the x and y axes was also performed in simulation as the proposed antenna works with a wider bandwidth in the skin and muscle tissue.The simulation and the curved antenna measurements turned out to be in good agreement.The impedance bandwidth of−10 dB and the axis ratio bandwidth of 3 dB(AR)are measured on the skin and imitative gel of the pig at 27.78%and 35.5%,13.5%and 4.9%,respectively,at a frequency of 2.45 GHz.The simulations revealed that the specific absorption rate(SAR)in the skin is 0.634 and 0.914 W/kg in muscle on 1g-tissue.The recommended SAR values are below the limits set by the federal communications commission(FCC).Finally,the proposed low-profile implantable antenna has achieved very compact size,flexibility,lower SAR values,high gain,higher impedance and axis ratio bandwidths in the skin and muscle tissues of the human body.This antenna is smaller in size and a good applicant for application in medical implants.
文摘This work presents a new bendable antenna for worldwide interoperability for microwave access (WiMAX) wireless communication systems. These antennas, transparent and flexible, will be easily integrated into various mdia and in particular OLED lighting which could be part of the public lighting network of tomorrow as well as on all display media. The integration of these antennas as close as possible to the end-user is a possible solution to reduce the energy consumption which goes hand in hand with the increase in the data rate. This kind of new antenna, designed to be integrated in organic light-emitting diode (OLED), was modeled from a transparent VeilShieldTM conductive fabric and was placed on a 100% polyester substrate with a thickness of 1.5 mm and a loss tangent of 0.02. We have tested and evaluated the characteristic parameters of our antenna, namely the reflection coefficient, the radiation pattern and the gain, to find out the performance of our proposed design. The performance of the transparent conductive fabric integrated in the 100% polyester substrate is tested for the application of flexible antenna operating at 3.5 GHz with a gain value of 5.38 dB. We have integrated this proposed new antenna with the OLED light source containing four layers of different materials and electrical properties: aluminum cathode layer, polymer layer, indium tin oxide (ITO) anode layer and glass substrate layer. After integration, the resonant frequency shifted to 3.52 GHz with a gain value of 4.61 dB. In addition, we also tested the concave bending on the reflection coefficient of the proposed flexible antenna taking into account the different bending angles. This work demonstrates the possibility of integrating these unconventional materials used for the proposed antenna within the OLED despite weak effects on the resonant frequency and the gain of the proposed antenna after integration.
文摘The miniaturization and endurance of wearable devices have been the research direction for a long time.With the development of nanotechnology and the emergence of microelectronics products,people have explored many new strategies that may be applied to wearable devices.In this overview,we will summarize the recent research of wearable devices in these two directions,and summarize some available related technologies.
