Antenna CoilsBasic Knowledge of LF RFID

LF RFID is a form of communication that uses magnetic fields. It is used in smart keys for automobiles and other applications.
When lines of magnetic force pass through a coil, an induced voltage is generated in that coil according to the magnetic flux density.
LF RFID uses this phenomenon to exchange signals.

In addition, magnetic fields are less affected by reflection and diffraction. This means that they create an evenly spaced communication area centered on the transmitter antenna, making it possible to measure the distance between the transmitter and receiver by measuring the strength.

The receiver antenna receives the magnetic field emitted from the transmitter antenna and performs communication in LF RFID. The strength of the magnetic field is proportional to the -3 power of the distance between the transmitter and receiver. Accordingly, it is possible to measure the distance between the transmitter and receiver according to the signal strength.

Murata Manufacturing introduces a position measurement demo kit so that you can experience the high accuracy of distance measurement with LF RFID.
Please contact us using the Contact Form for details.

LF RFID is a form of communication that uses magnetic fields. Accordingly, it is not affected by human bodies or water, and is less affected by metals than other communication methods, making it possible to measure distances with high reproducibility.

The antenna coil in LF RFID has the role of transmitting (electricity → magnetic field) and receiving (magnetic field → electricity) the magnetic field.
The transmitter antenna is used as an LC series resonant circuit to efficiently transmit the magnetic field. The receiver antenna is used as an LC parallel resonant circuit to efficiently receive the magnetic field.
Moreover, the receiver antenna has coils wound in three directions to receive the magnetic field in three dimensions.