Development and electromagnetic environment evaluation of ultra wideband device for the next generation mobile communication system

自从2002年联邦通信委员会批准未经许可使用超宽带(3.1-10.6 GHz)以来，超宽带技术在短距离无线通信领域引起了极大的兴趣，如物体的定位和成像、车载传感、高速公路和其他民用基础设施的监控等。为了实现这种超宽带无线通信系统，超宽带带通滤波器是关键的无源器件之一。我们成功地实现了无电磁干扰的超宽带带通滤波器，以便将它们与其他元件集成在一个紧凑的系统中。这些方法包括微带结构、平行耦合线、阶跃阻抗谐振器、通孔短路等。为了完成超宽带滤波器的设计，不仅需要了解网络分析仪的输入/输出频率特性，而且需要了解中心导体的电磁场分布和电流分布，以了解微带平面结构的超宽带滤波器的设计、优化和工作原理。为了测量基于微带结构的UWB-BPF中的所有电磁近场分布，发展了一种使用电场和磁场探头的非接触式场映射技术。H场可以用小环路探头和适当的仪器，如网络分析仪或频谱分析仪来测量，而电场可以用同轴型探头来测量。

Since the Federal Communications Commission authorized the unlicensed use of ultra-wideband (3.1-10.6 GHZ) in 2002, the ultra-wideband technologies have drawn great inter-est in short-range wireless communications such as locating and imaging of objects, in-vehicle sensing, monitoring of highways and other civil infrastructure, and so on. In order to realize such UWB wire-less communication systems, the ultra-wideband bandpass filter is one of the key passive components. We succeeded in the achievement of the ultra-wideband bandpass filter without electromagnetic inter-ference in order to integrate them with other components as a compact system. These methods include microstrip structures, parallel coupled line, step impedance resonator, short-circuited stub by via holes, etc. In order to complete the UWB-filter design, it is essential to know not only the input/output fre-quency characteristics with the network analyzer but also the electromagnetic field distribution and cur-rent distribution of center conductor to understand the ultra-wideband filter design, optimization, and operation principle for the microstrip planar structures. For measurement of all EM near field distribu-tions in UWB-BPFs fabricated on a microstrip structure, contactless field mapping technique using elec-tric and magnetic field probes was developed. The H-field can be measured using a small loop probe and an appropriate instrument such as network analyzer or spectrum analyzer and the E-field can be meas-ured using a coaxial type probe.