【作者】 刘彤；

【导师】 沈连丰；

【作者基本信息】 东南大学 ， 通信与信息系统， 2006， 博士

【摘要】 本学位论文深入研究基于无线个域网(WPAN)技术构建的无线家庭网络电磁兼容性能以及通信设备的关键射频技术。在分析了现有各种网络技术及其并存状况的基础上,给出了基于WPAN构建无线家庭网络的方案,剖析了该方案的电磁环境,研究了多种网络共存环境下提高本文方案中无线通信系统性能的关键射频技术。论文首先综述了家庭网络技术的研究现状,比较了国内外现有家庭网络的解决方案,指出采用蓝牙技术构建家庭网络无线子网比较适合我国国情,提出两种在现存网络条件下的无线家庭网络蓝牙技术解决新方案,并针对第二种方案,提出了低成本嵌入式实现方法。然后,根据WPAN系统各种电磁干扰的特点,提出以干扰总电平为变量的干扰数学统计模型,以此分析跳频技术在电磁干扰环境下的平均误比特率性能,并将分析结果与仿真结果比较从而证明此统计模型的准确性。接着,阐述了低噪声放大器(LNA)最小噪声设计准则和最大增益设计准则在WPAN系统设计中的矛盾,在讨论串联电感对LNA匹配阻抗作用的基础上,提出一种将串联电感反馈与优化仿真相结合的LNA设计方法。该方法不仅解决了两准则间的矛盾,还大大缩短了设计时间。最后,分析了多种适用于WPAN系统的天线的各项特性参数,研究了倒F型天线输入阻抗随其尺寸参数的变化规律,仿真了单频印制倒F型天线的尺寸参数对其各项性能指标的影响效果,并据此提出可工作于2.45GHz和5.25GHz的改进型双频印制倒F型天线。该天线可直接印制在FR-4板材上,结构紧凑,馈电方便,设计灵活,且具有等向辐射和交叉极化特性。更多还原

【Abstract】 The electromagnetic compatibility characters of the wireless home network constructed with WPAN (Wireless Personal Area Network) and the key RF (Radio Frequency)technologies are studied in this thesis. The scheme is brought forward under the circumstance that varieties of network technologies exist nowadays. Then the electromagnetic environment of the scheme and the LNA (low noise amplifier) & antenna technologies are researched to improve the performance of the WPAN system working in the complex electromagnetic interference environment.Firstly, the development statuses of the home network technologies are expatiated and the existing home network schemes are compared to point out that the Bluetooth is the favorite technology to construct home network in China. Then two new solutions based on Bluetooth technology are proposed, which can work better in the condition that a lot of similar networks exist. And a realization method with low cost embedded system is presented for the second solution scheme.Secondly, a statistical interference model, which is based on the total interference power level and the characters of varieties of electromagnetic interference for WPAN system, is given to analyze the average bit error rate performance of the FHSS technology under the complex electromagnetic interference environment. The results of the comparison between the analysis and the simulation indicate that the model is comparatively accurate.Thirdly, some design rules for LNA such as the minimum noise figure rule and the maximum gain rule are described, and the conflicts of them are discussed. After the impact of series inductor on the matching impedances of LNA is analyzed, a design method for LNA combining series inductor feedback with optimization simulation is studied. It not only solves the contradiction between the two rules but also saves the design time.Lastly, the characters of several types of antennas suiting for WPAN are analyzed, and the regularities that how the input impedance is affected by the geometry sizes of the IFA (inverted-F antenna) are discussed. The dimension impacts on the performance of the single band printed IFA are simulated then, based on which the novel transformed structure of the dual band printed IFA for both 2.45GHz and 5.25GHz is developed. The new structure antenna is very flexible to design and has better characters of omni-directional pattern and cross polarization character as expected. Furthermore it just can be printed on the FR-4 board directly for its compact profile, which makes it very easy to feed through microstrip line.更多还原