Recently, many studies propose the use of ultra-wideband technology for passive and active radio frequency identification systems as well as for wireless sensor networks due to its numerous advantages. By harvesting t...Recently, many studies propose the use of ultra-wideband technology for passive and active radio frequency identification systems as well as for wireless sensor networks due to its numerous advantages. By harvesting these advantages of IR-UWB technology at the physical-layer design, this paper proposes that a cross layer architecture platform can be considered as a good integrator for different wireless short-ranges indoor protocols into a universal smart wireless-tagged architecture with new promising applications in cognitive radio for future applications. Adaptive transmission algorithms have been studied to show the trade-off between different specific QoS requirements, transmission rates and distances at the physical layer level and this type of dynamic optimization and reconfiguration leads to the cross-layer design proposal in the paper. Studies from both theoretical simulation and statistical indoor environments experiments are considered as a proof of concept for the proposed architecture.展开更多
In this paper, we report polyfluorene-separated ultra-high purity semiconducting carbon nanotube radio frequency transistors with a self-aligned T-shape gate structure. Because of the ultra-high semiconducting tube pu...In this paper, we report polyfluorene-separated ultra-high purity semiconducting carbon nanotube radio frequency transistors with a self-aligned T-shape gate structure. Because of the ultra-high semiconducting tube purity and self-aligned T-shape gate structure, these transistors showed an excellent direct current and radio frequency performance. In regard to the direct current characteristics, these transistors showed a transconductance up to 40μS/μm and an excellent current saturation behavior with an output resistance greater than 200 kΩ·μm. In terms of the radio frequency characteristics, an extrinsic maximum oscillation frequency （fmax） of 19 GHz was achieved, which is a record among all kinds of carbon nanotube transistors, and an extrinsic current gain cut-off frequency （fT） of 22 GHz was achieved, which is the highest among transistors based on carbon nanotube networks. Our results take the radio frequency performance of carbon nanotube transistors to a new level and can further accelerate the application of carbon nanotubes for future radio frequency electronics.展开更多
A loop antenna for near field readers is proposed. Through periodic interdigital capacitors, the phase of the current on the loop is compensated and kept in phase. Hence, a loop with a perimeter of one wavelength at 9...A loop antenna for near field readers is proposed. Through periodic interdigital capacitors, the phase of the current on the loop is compensated and kept in phase. Hence, a loop with a perimeter of one wavelength at 900 MHz achieves a uniform near magnetic field distribution inside the loop. A novel method is proposed to evaluate the performance of the coplanar waveguide （CPW） to coplanar stripline （CPS） transition, which is used as a balun for the feeding network in this paper. This loop antenna has a 70 MHz operating bandwidth and 12 cm maximum reading range when the output power is 24 dBm, which is suitable for most near field radio frequency identification （RFID） applications.展开更多
A low-sidelobe circularly-polarized(CP) microstrip patch array for 2.4 GHz radio frequency identification(RFID) readers is presented.The antenna array with a Chebyshev current distribution is composed of 6 microstrip ...A low-sidelobe circularly-polarized(CP) microstrip patch array for 2.4 GHz radio frequency identification(RFID) readers is presented.The antenna array with a Chebyshev current distribution is composed of 6 microstrip elements.The CP operation is obtained by the quasi-square patch with difference in lengths of the two sides.The antenna has been investigated numerically and experimentally.Measured results show that the array has a Chebyshev pattern with the sidelobe level of-23 dB, the half-power beamwidth of 16° and an impedance bandwidth(S11≤-10 dB) of 130 MHz, which is suitable for RFID reader applications.展开更多
目的探讨基于射频识别(Radio Frequency Identification,RFID)技术的手术室耗材智慧屋管理系统的应用效果。方法利用超高频RFID技术,将手术室原有库房进行整体改造及屏蔽铺设,搭建成基于RFID的手术室耗材智慧屋管理系统,建立产品入库、...目的探讨基于射频识别(Radio Frequency Identification,RFID)技术的手术室耗材智慧屋管理系统的应用效果。方法利用超高频RFID技术,将手术室原有库房进行整体改造及屏蔽铺设,搭建成基于RFID的手术室耗材智慧屋管理系统,建立产品入库、使用登记、库存管理和查询4个模块,完成对高值耗材的全过程管理和可追溯管理。比较系统使用前后耗材管理不良事件发生率、日均管理时间、日均领用时间和领用次数以及未使用耗材归位率情况。结果系统使用后,耗材管理不良事件发生率为2.9%,显著低于系统使用前的8.8%(χ^(2)=31.601,P<0.001);耗材日均管理时间为(66.56±10.37)min,显著低于使用前(110.18±16.89)min(t=69.598,P<0.001);耗材日均领用时间和领用次数显著低于使用前(t=109.051、39.659,均P<0.001)。未使用耗材归位率由系统使用前的95.2%提高到使用后的100%。结论手术室耗材智慧屋管理系统在高值耗材管理中应用效果显著,可减少耗材管理不良事件的发生,精简耗材管理和领用环节,值得推广应用。展开更多
文摘Recently, many studies propose the use of ultra-wideband technology for passive and active radio frequency identification systems as well as for wireless sensor networks due to its numerous advantages. By harvesting these advantages of IR-UWB technology at the physical-layer design, this paper proposes that a cross layer architecture platform can be considered as a good integrator for different wireless short-ranges indoor protocols into a universal smart wireless-tagged architecture with new promising applications in cognitive radio for future applications. Adaptive transmission algorithms have been studied to show the trade-off between different specific QoS requirements, transmission rates and distances at the physical layer level and this type of dynamic optimization and reconfiguration leads to the cross-layer design proposal in the paper. Studies from both theoretical simulation and statistical indoor environments experiments are considered as a proof of concept for the proposed architecture.
文摘In this paper, we report polyfluorene-separated ultra-high purity semiconducting carbon nanotube radio frequency transistors with a self-aligned T-shape gate structure. Because of the ultra-high semiconducting tube purity and self-aligned T-shape gate structure, these transistors showed an excellent direct current and radio frequency performance. In regard to the direct current characteristics, these transistors showed a transconductance up to 40μS/μm and an excellent current saturation behavior with an output resistance greater than 200 kΩ·μm. In terms of the radio frequency characteristics, an extrinsic maximum oscillation frequency （fmax） of 19 GHz was achieved, which is a record among all kinds of carbon nanotube transistors, and an extrinsic current gain cut-off frequency （fT） of 22 GHz was achieved, which is the highest among transistors based on carbon nanotube networks. Our results take the radio frequency performance of carbon nanotube transistors to a new level and can further accelerate the application of carbon nanotubes for future radio frequency electronics.
文摘A loop antenna for near field readers is proposed. Through periodic interdigital capacitors, the phase of the current on the loop is compensated and kept in phase. Hence, a loop with a perimeter of one wavelength at 900 MHz achieves a uniform near magnetic field distribution inside the loop. A novel method is proposed to evaluate the performance of the coplanar waveguide （CPW） to coplanar stripline （CPS） transition, which is used as a balun for the feeding network in this paper. This loop antenna has a 70 MHz operating bandwidth and 12 cm maximum reading range when the output power is 24 dBm, which is suitable for most near field radio frequency identification （RFID） applications.
基金supported by the Shanghai Leading Academic Discipline Project (Grant No.T0102)
文摘A low-sidelobe circularly-polarized(CP) microstrip patch array for 2.4 GHz radio frequency identification(RFID) readers is presented.The antenna array with a Chebyshev current distribution is composed of 6 microstrip elements.The CP operation is obtained by the quasi-square patch with difference in lengths of the two sides.The antenna has been investigated numerically and experimentally.Measured results show that the array has a Chebyshev pattern with the sidelobe level of-23 dB, the half-power beamwidth of 16° and an impedance bandwidth(S11≤-10 dB) of 130 MHz, which is suitable for RFID reader applications.
文摘目的探讨基于射频识别(Radio Frequency Identification,RFID)技术的手术室耗材智慧屋管理系统的应用效果。方法利用超高频RFID技术,将手术室原有库房进行整体改造及屏蔽铺设,搭建成基于RFID的手术室耗材智慧屋管理系统,建立产品入库、使用登记、库存管理和查询4个模块,完成对高值耗材的全过程管理和可追溯管理。比较系统使用前后耗材管理不良事件发生率、日均管理时间、日均领用时间和领用次数以及未使用耗材归位率情况。结果系统使用后,耗材管理不良事件发生率为2.9%,显著低于系统使用前的8.8%(χ^(2)=31.601,P<0.001);耗材日均管理时间为(66.56±10.37)min,显著低于使用前(110.18±16.89)min(t=69.598,P<0.001);耗材日均领用时间和领用次数显著低于使用前(t=109.051、39.659,均P<0.001)。未使用耗材归位率由系统使用前的95.2%提高到使用后的100%。结论手术室耗材智慧屋管理系统在高值耗材管理中应用效果显著,可减少耗材管理不良事件的发生,精简耗材管理和领用环节,值得推广应用。
