Design of Bidirectional Coupling Circuit for Broadband Power-Line Communications

This paper deals with the design of bidirectional coupler for broadband power line communication and the impedance matching technique with the power line. This coupler can be used for both transmitting and receiving the data, acting as transceiver. The impedance mismatching problem is also solved here using line trap circuit. The coupler circuit is capable of transmitting or receiving modulated signals with carrier frequency of 15 MHz which can be used for domestic as well as distribution power networks. Laboratory prototype tested using power line network consists of electrical household appliances and results show that the circuit is able to facilitate bidirectional band pass transmission.

宽带小型化微带均衡器设计

功率放大模块在工作频带内存在增益波动的情况,目前较为理想的解决方案是在原传输网络中添加一个增益均衡网络,该均衡网络就是增益均衡器。文章针对2~6 GHz功放模块增益波动较大的问题,设计和制造了一种采用微带电路的小型化均衡器,其工作频率为2~6 GHz,均衡量约为9 dB,输入输出驻波系数小于1.5,改善了功放模块输出功率不平坦的问题,对研发该类均衡器有一定的参考价值。文中简要介绍了传输线和增益均衡器的基本原理以及薄膜电路的相关设计,结合实际需求,确定目标曲线,设计增益均衡器的初始模型,再利用三维场仿真软件对增益均衡器进行仿真优化,研制出2~6 GHz微带型增益均衡器。该增益均衡器实测结果与设计基本吻合,满足了小型化的设计要求。

T接电路暂态保护分析

由于T接线路与二端口线路相比,具有良好的经济性与环保优势,因而在超高压输电系统中将会有非常广泛的应用。然而使用传统的保护方法,很难对其进行有效的保护。将基于故障暂态电流的单端量无通信保护用于T接线路,并且根据故障暂态电流的特点,利用Daubechies小波计算暂态保护判据。通过在不同的故障位置、不同的过渡电阻、不同的故障时间以及各种故障类型的情况下,对实际T接线路进行的详细仿真,证明了暂态保护应用于T接线路的可行性。