Due to steady phase error, low-order PLL has a trouble in trackingfrequency ramp signals, so that the receiver cannot lock carrier signals.
低阶锁相环跟踪频率斜升信号时产生的稳态相差致使环路失锁，接收机无法锁定载波信号。
2
As IBM noted in its press release today, RFID tags (Radio Frequency Identification sensors) are becoming particularly popular for the purpose of item tracking and authentication.
IBM今天在其发布会上称RFID(无线射频识别)标签在物品跟踪和识别领域的应用将越来越广泛。
3
Radio frequency identification (RFID) and more sophisticated technologies for product tracking within supply chain management systems are being experimented in some countries.