61. RFID

There are many wireless communication technologies for personal computer, portable electronic equipment, and household electronic appliances.
The transmission speed and the transmission distance are different besides the difference of respective bandwidth used.
Therefore, there are differences in the usage. Here we will discuss the typical Wireless communication technology and its respective characteristics.

Bandwidth used Usage Characteristic

125k-135kHz

FA(Factory automation) Use in leisure such as eating and drinking such as at conveyor belt sushi bar, lift tickets of ski areas and in immobilizers for automobiles.

RFID technology has been using since the 1980’s. The passive type with not built in battery uses it. The electromagnetic induction type is used for the communication. There is a disadvantage on RFID tag for large external dimensions as it uses the antenna that wraps the coil around the core. Moreover, the communication distance is shortened by some few cm, and the data transmission rate is low. On the other hand, the advantages are the electromagnetic wave tends to wraparound as the frequency is low, and hard to receive the effect of metal and water.

13.56MHz

“FeliCa standard” adopted by book management in library, security management in retail store, “Suica”, and “Edy”

RFID technology uses the electromagnetic induction type. It is used in the passive type that do not use built in battery. The receiving antenna is small as the frequency is low compared to the RFID technology that uses 125k-135kHz. It is also possible to make on the film. The communication distance is about 1m. However, the data communication is disturbed when there is metal between the reader / writer and the receiving antenna and tends to impact by the metal.

433MHz

Use in International logistics such as marine transport container management.

It is used as an active type built-in battery. In Japan, a narrower band of 433.67M-434.17MHz is allocated because the frequency band overlaps with the amateur radio, although a wide frequency band of 420M-450MHz is allocated in America. However, the output electric power is 1mW, and is extremely low by about 1/10,000 times of the amateur radio.

860M-960MHz

Use in the distribution of container management, merchandise management of major distributive firms.

RFID technology that use UHF band. There is RFID tag of the passive type and the actively type, and the data is read by the microwave telecommunication system. The progression of the electromagnetic waves decrease and expects the wraparound when compared to RFID technology that uses 2.45GHz, so there is advantage of data communication even if there is obstacle. However, the data communication rate is inferior compared to 2.45GHz. The communication distance is about 5m or less.

2.45GHz

Use in distribution of container management.

RFID technology that use microwave band. There are RFID tag of the passive type and the semi-passive type. The advantage is the reader / writer and receiving antenna can be miniaturized as the frequency is high. On the other hand, the disadvantage includes the electromagnetic waves tends to adsorb in water, the progression of electromagnetic waves is high so it is difficult to avoid the obstacle. The communication distance is about 2m. It can obtain a comparatively high data communication rate.