With the radiofrequency identification key, the radiofrequencysignal can be sent outwards when a user enters a room.
利用此射频识别钥匙，用户进入房间时能实现射频信号的对外发送。
2
RFID systems achieve auto-identification and data-gathering of the object to be identified by utilizing space coupling of radiofrequencysignal to conduct two-way transmission of signals.
RFID系统利用射频信号通过空间耦合进行双向信息传输，实现对待识别物体的自动识别和数据采集。
3
The first tuner receives the first radiofrequencysignal and outputs a first digital signal.