profibus总线结构及协议分析,profibus是一种国际化、开放式、不依赖于设备生产商的现场总线标准-profibus bus structure and protocol analysis, profibus is an international, open-ended, does not rely on equipment manufacturers fieldbus standard

In double reflector antennas feed, feed support beams and sub-reflector especially cause distribution losses and large blockings in antenna apertures. In previous studies, the spillover losses due to open-ended rectangular and circular sectio