Based on the flow characteristic equation of air in adiabatic process, the characteristics of modulated on-off valve in a pneumatic pressure control system is analyzed theoretically. The relationship between the param...Based on the flow characteristic equation of air in adiabatic process, the characteristics of modulated on-off valve in a pneumatic pressure control system is analyzed theoretically. The relationship between the parameters and performance of the system is obtained, and it is also observed that the control error is proportional to the on-off period of the valve.展开更多
文摘Based on the flow characteristic equation of air in adiabatic process, the characteristics of modulated on-off valve in a pneumatic pressure control system is analyzed theoretically. The relationship between the parameters and performance of the system is obtained, and it is also observed that the control error is proportional to the on-off period of the valve.
文摘在微波通信系统中,滤波器作为通信系统中不可缺少的微波无源器件,其性能指标直接影响整个通信系统的性能。与传统滤波器相比,微机电系统(Micro-Electro-Mechanical System,MEMS)滤波器具有集成度高、小型化等优点,其中腔体结构在RF MEMS滤波器中有着广泛的应用。感应耦合等离子刻蚀是实现三维腔体结构的关键技术,其刻蚀均匀性直接影响腔体滤波器的性能指标。过程控制监控(Process Control Monitoring,PCM)是MEMS工艺控制中的重要监控手段,利用自动测试系统,论述了用于自动测试的PCM图形,通过数据处理得到硅腔深度分布图,并拟合出硅腔深度和中心频率对应关系,反应了当前刻蚀的工艺能力,为后续产品设计、提高刻蚀均匀性及优化版图设计提供了数据支撑。