A wideband 0.13 μm CMOS LC-VCO for IMT-advanced and UWB applications

This paper presents an LC voltage controlled oscillator(VCO) in a dual-band frequency synthesizer for IMT-advanced and UWB applications.The switched current source,cross-coupled pair and noise filtering technique are adopted in this VCO design to improve the performance of the phase noise,power consumption,voltage amplitude,and tuning range.In order to achieve a wide tuning range,a reconfigurable LC tank with 4 bits switch control is adopted in the core circuit design.The size of the entire chip with pad is 1.11 0.98 mm2.The test results show that the current dissipation of the VCO at UWB and IMT-Advanced band is 3 mA and 4.5 mA in a 1.2 V supply.The tuning range of the designed VCO is 3.86-5.28 GHz and 3.14-3.88 GHz.The phase-noise at 1 MHz frequency offset from a 3.5 GHz and 4.2 GHz carrier is-123 dBc/Hz and-119 dBc/Hz,respectively.     

移动基站共址架空输电塔专用防雷系统研究

架空输电塔上的防雷系统只针对架空输电塔而设计,未能很好地保护移动基站.为达到保护架空输电塔的同时也能保护移动基站目的,设计了一种移动基站共址架空输电塔专用防雷系统.在正负极性标准雷电波的作用下,获取闪络电压,并计算雷电流超出概率.根据计算结果,抑制雷击过电压,完成系统软件设计.通过系统测试可知,使用移动基站共址架空输电塔专用防雷系统后,接地电阻由6.75Ω降到了 0.54Ω以下,且瞬时电压呈平稳状态,降低了线路雷击跳闸率,提高了耐雷水平.     

无线Mesh组网技术在电力应急语音通信中的应用

为了在应急通信任务发生时仍能快速建立可靠的通信,将无线Mesh网络技术和数字语音通信技术结合起来设计了电力应急保障场所语音通信装备.整个装备选择无线语音对讲设备作为通信终端,一体化便携车载设备作为调度台,实现了群体呼叫、单点对话、短信邮箱、基站漫游等多种调度通信功能.在现场模拟电力应急保障场所,并对无线语音通信装备通信状态进行了实际测试.测试和分析表明所开发的无线语音通信装备的通信质量良好,实现了应急语音通信的主要需求.