小型化三耦合线Marchand巴伦的等效模型分析与验证

为了实现三耦合线Marchand巴伦的快速设计,缩小巴伦的尺寸,提出了一种简化的三耦合线Marchand 巴伦等效模型及小型化设计方法。该等效模型将复杂的三耦合线的S参数散射矩阵的计算问题简化为对两个并联的平行耦合线的S参数散射矩阵的计算。为了验证该模型和设计方法的有效性,采用0.1 μm 砷化镓pHEMT (pseudomorphic High Electron Mobility Transistor)工艺制作了一款75~110 GHz的单平衡混频芯片,最终应用于单平衡混频器的巴伦耦合线长度被缩减为中心频率1/4波长的44%。良好的混频器性能和紧凑的芯片面积证明了所提三耦合线巴伦的等效模型和设计方法能够为单片集成微波电路芯片的设计提供指导作用。     

A novel loss compensation technique analysis and design for 60 GHz CMOS SPDT switch

A novel loss compensation technique for a series-shunt single-pole double-throw (SPDT) switch is presented operating in the 60 GHz. The feed-forward compensation network which is composed of an NMOS, a couple capacitance and a shunt inductance can reduce the impact of the feed forward capacitance to reduce the insertion loss and improve the isolation of the SPDT switch. The measured insertion loss and isolation characteristics of the switch somewhat deviating from the 60 GHz are analyzed revealing that the inaccuracy of the MOS model can greatly degrade the performance of the switch. The switch is implemented in TSMC 90-nm CMOS process and exhibits an isolation of above 27 dB at transmitter mode, and the insertion loss of 1.8-3 dB at 30-65 GHz by layout simulation. The measured insertion loss is 2.45 dB at 52 GHz and keeps<4 dB at 30-64 GHz. The measured isolation is better than 25 dB at 30-64 GHz and the measured return loss is better than 10 dB at 30-65 GHz. A measured input 1 dB gain compression point of the switch is 13 dBm at 52 GHz and 15 dBm at 60 GHz. The simulated switching speed with rise time and fall time are 720 and 520 ps, respectively. The active chip size of the proposed switch is 0.5×0.95 mm².     

牵引传动系统仿真数据压缩设计与实现

地铁机车牵引传动系统仿真模型复杂、仿真时间长、仿真精度高,与其相关的数据量非常大。若要实现对地铁机车的牵引传动系统的仿真分析,同时存储仿真分析结果,就必须删除系统仿真产生的冗余数据。结合南京地铁西延线地铁机车牵引传动系统仿真软件——TSim产生海量数据的问题,该文提出了一种有针对性的自适应在线压缩算法。该压缩算法根据牵引传动系统仿真产生的数据结构的不同,对仿真数据做了特殊处理并设计了相应的子压缩算法。实验结果表明：该压缩算法能够在保证失真度最小的前提下,在最大程度上减少了仿真数据量,节省了存储的时间与空间,加快了后续处理速度,提高了牵引传动系统仿真的效率。