This paper proposes a novel flexible antenna design operating at very high frequency(VHF)band for on-body applications such as human body communication(HBC).The antenna consists of back-to-back E-shaped fractal and co...This paper proposes a novel flexible antenna design operating at very high frequency(VHF)band for on-body applications such as human body communication(HBC).The antenna consists of back-to-back E-shaped fractal and complimentary structures designed over a thin flex-ible substrate.The overall design working on the principle of fractal geometries and capacitive coupling is highly beneficial to achieve better antenna characteristics even at low frequencies around 35 MHz-45 MHz that are being used for HBC application.The proposed antenna obtained a large bandwidth of around 10.0 MHz in air and a bandwidth of around 8.0 MHz during on-body opera-tion.The antenna has been tested in three different scenarios viz.air,on-body single antenna and on-body communication using two antennas.The insertion loss is reduced to a minimum in all three scenarios,which is quite beneficial for better signal transmission.The size miniaturization with high flexibility in such low frequencies has also been achieved in the paper that makes the proposed design suitable for human body communication applications.展开更多
射电天文在HF-VHF频段采用天线组阵的方式进行观测,根据平方公里阵列(Square Kilometre Array,SKA)的要求,每个阵列单元天线的增益、结构一致性、稳定性、阻抗变化趋势和极化纯度等方面需要达到较高指标,才能满足太阳、木星、再电离纪...射电天文在HF-VHF频段采用天线组阵的方式进行观测,根据平方公里阵列(Square Kilometre Array,SKA)的要求,每个阵列单元天线的增益、结构一致性、稳定性、阻抗变化趋势和极化纯度等方面需要达到较高指标,才能满足太阳、木星、再电离纪元等多种测量在极化测量、天线跟踪稳定性以及接收机宽带匹配等方面的需求。根据SKA requirement 2165:极化纯度2135-38和每极化方向灵敏度2814-15提出的性能需求,以及在总结原有设计的经验后,针对10~90 MHz频段,设计了一种适用于HF-VHF的新型倒“V”型栅板偶极子天线,具有重量轻、风阻小等优点,在10~90 MHz的超宽频段内阻抗变化缓慢、极化纯度良好。其中,在阻抗变化方面,天线的阻抗实部从0.8Ω到631.132Ω变化,优于低频射电阵列(Low Frequency Array,LOFAR)的天线,降低了接收机匹配难度和噪声;在极化纯度方面,天线整体轴比小于0.41 dB,对于太阳射电爆发等强极化信号具有良好的极化隔离度。展开更多
随着民航新疆空中交通管理的发展,新疆管制空域的空中交通流量日益递增。如何在保障管制空域通畅和航空飞行安全的前提下,扩大地空通信的有效多重覆盖范围,同时提供高质量的通信语音,是新疆空管部门面临的问题之一。针对该问题,目前新...随着民航新疆空中交通管理的发展,新疆管制空域的空中交通流量日益递增。如何在保障管制空域通畅和航空飞行安全的前提下,扩大地空通信的有效多重覆盖范围,同时提供高质量的通信语音,是新疆空管部门面临的问题之一。针对该问题,目前新疆空管正在不断通过增设信道和新建补盲台址的方式加以解决。无论是增设信道和新建补盲台址,都离不开甚高频(Very High Frequency,VHF)通信天馈系统的架设、电台的安装、系统内传输线路的配置、腔体滤波器的安装以及系统的统调测试等工作,因此根据参加的甚高频通信系统的安装和调试工作,总结出一些应用方法,为以后甚高频通信系统及设备更好地安装投产使用和科学管理提供参考。展开更多
基金National Key Research and Development Pro-gram of China(No.2018YFC2001002)Shenzhen Basic Re-search Project(Nos.JCYJ20180507182231907,PIFI 2020FYB0001)CAS Key Lab of Health Informatics.
文摘This paper proposes a novel flexible antenna design operating at very high frequency(VHF)band for on-body applications such as human body communication(HBC).The antenna consists of back-to-back E-shaped fractal and complimentary structures designed over a thin flex-ible substrate.The overall design working on the principle of fractal geometries and capacitive coupling is highly beneficial to achieve better antenna characteristics even at low frequencies around 35 MHz-45 MHz that are being used for HBC application.The proposed antenna obtained a large bandwidth of around 10.0 MHz in air and a bandwidth of around 8.0 MHz during on-body opera-tion.The antenna has been tested in three different scenarios viz.air,on-body single antenna and on-body communication using two antennas.The insertion loss is reduced to a minimum in all three scenarios,which is quite beneficial for better signal transmission.The size miniaturization with high flexibility in such low frequencies has also been achieved in the paper that makes the proposed design suitable for human body communication applications.
文摘射电天文在HF-VHF频段采用天线组阵的方式进行观测,根据平方公里阵列(Square Kilometre Array,SKA)的要求,每个阵列单元天线的增益、结构一致性、稳定性、阻抗变化趋势和极化纯度等方面需要达到较高指标,才能满足太阳、木星、再电离纪元等多种测量在极化测量、天线跟踪稳定性以及接收机宽带匹配等方面的需求。根据SKA requirement 2165:极化纯度2135-38和每极化方向灵敏度2814-15提出的性能需求,以及在总结原有设计的经验后,针对10~90 MHz频段,设计了一种适用于HF-VHF的新型倒“V”型栅板偶极子天线,具有重量轻、风阻小等优点,在10~90 MHz的超宽频段内阻抗变化缓慢、极化纯度良好。其中,在阻抗变化方面,天线的阻抗实部从0.8Ω到631.132Ω变化,优于低频射电阵列(Low Frequency Array,LOFAR)的天线,降低了接收机匹配难度和噪声;在极化纯度方面,天线整体轴比小于0.41 dB,对于太阳射电爆发等强极化信号具有良好的极化隔离度。
文摘随着民航新疆空中交通管理的发展,新疆管制空域的空中交通流量日益递增。如何在保障管制空域通畅和航空飞行安全的前提下,扩大地空通信的有效多重覆盖范围,同时提供高质量的通信语音,是新疆空管部门面临的问题之一。针对该问题,目前新疆空管正在不断通过增设信道和新建补盲台址的方式加以解决。无论是增设信道和新建补盲台址,都离不开甚高频(Very High Frequency,VHF)通信天馈系统的架设、电台的安装、系统内传输线路的配置、腔体滤波器的安装以及系统的统调测试等工作,因此根据参加的甚高频通信系统的安装和调试工作,总结出一些应用方法,为以后甚高频通信系统及设备更好地安装投产使用和科学管理提供参考。
