Abstract: An apparatus is provided that includes phase preservation means having a reference shaft fixed to one side of frames supporting a plurality of components, a driven shaft revolving around the reference shaft with a predetermined distance spaced apart therebetween, a force transmitting part connected to the driven shaft and the reference shaft to restrict rotation of the driven shaft, and supporting parts that guide revolving of the driven shaft around the reference shaft when the supporting parts are rotated by a rotational force applied by the force generating part and allows a phase of the driven shaft to be preserved. The apparatus also includes a phase preservation part that is connected and fixed to one side of the driven shaft.

Abstract: Provided is an RFID system using a piezoelectric body. The RFID system includes the piezoelectric body, a tag, a reader, and a host. The piezoelectric body producing power using external pressure, and the tag is connected to the piezoelectric body, records data, and transmits an RF signal when power is supplied from the piezoelectric body. The reader deciphers data contained in the RF signal received from the tag, and the host processes data deciphered at the reader. The piezoelectric body is mounted on a portion of an object to which external pressure is applied.