Steady State Temperature Study on RF LDMOS with Structure Modification

This paper is devoted to temperature analysis on power RF LDMOS with different feature parameters of die thickness, pitch S length and finger width. The significance of these three parameters is determined from temperature comparison obtained by 3D Silvaco-Atlas device simulator. The first three simulations focus on temperature variation with the three factors at different output power density respectively. The results indicate that both the thinner die thickness and the broaden pitch S length have distinct advantages over the shorter finger width. The device, at the same time, exhibits higher temperature at a larger output power density. Simulations are further carried out on structure with combination of different pitch s length and die thickness at a large 1W/mm output power density and the temperature reduction reaches as high as 55%.

基于S变换的风力发电变桨距变桨长控制技术

由于风速具有波动性大、频率变化快等特点,故风力机不能稳定的输出额定功率,在风力机工作的时候风能对桨叶不可避免的会产生震动应力,并带来震动磨损。为了实现稳定输出功率和减少震动磨损的目的,本文提出了基于S变换的变桨距变桨长控制技术。通过S变换对风速中的高频风速和低频风速进行区分,并通过对比两种风速的能量对桨叶长度进行调节。以风力发电机组的输出功率作为输入,实现变桨距控制。在随机风的条件下对设计的变桨距变桨长控制器进行仿真,结果表明,基于S变换的变桨距变桨长控制器可以有效地减弱频繁变化风速对风力发电机组输出功率的影响,并减小风力发电机组所承受的震动磨损。