RFID Circuits

The high integration of RFID Circuits allows a relatively easy implementation into any customer specific application. RFID Circuits are printed on a custom designed screen press with conductive inks.

In older systems, a fixed base station transmitter interrogates the vehicle transceiver, which sends its ID in response. Such active systems are bulky and expensive. But today, a new generation of RFID systems has emerged. They use a fully passive receive/transmit unit called a tag or transponder in the vehicle to respond to external interrogation. These RFID tags are small and flat, and they require no battery power. An RFID tag in RFID Circuits is as easy to attach to the windshield as an inspection sticker.

The tag consists of a resonant circuit tuned to 125 kHz, 134.2 kHz, 13.56 MHz, 915 MHz, or 2.4 GHz. The signal transmitted by the base station is detected, and the RF output developed in the tuned circuit is rectified into a dc voltage that powers a small transmitter which sends a coded signal back to the base station. A read range of up to several meters is possible with high enough power and a good antenna. An on-chip Flash memory contains the ID code. Such tags run under $10. Major manufacturers of RFID Circuits and equipment are the Amtech Division of TransCore Inc., Microchip Technology Inc., and Texas Instruments.

In 1989, it was noticed that RFID Circuits will bring about new RF applications in logistics. Radio Frequency Identification or RFID tags make it possible to identify individual products by using wireless RF signals. At high frequencies (e.g. at 900 MHz) tags can be read from a distance of a few meters. RFID Circuits can convey logistic and measurement information, & do not require power sources of their own.

The RFID Readers are powerful tool for obtaining information emitted by RFID tags in RFID Circuits. RFID tags are placed inside, or on, a variety of items depending on the system's purpose. The tags contain information; the amount and complexity varies depending on the type of tag. RFID Readers or scanners are able to retrieve the tag's information, and change it if capable. RFID solutions are used by different industries, and for variant purposes. Digital RFID readers can pick up the signal from several feet away, so workers don’t have to manipulate the items to read them.

RFID Readers use Time Division Multiple Access, or TDMA, meaning they read tags at different times to avoid interfering with one another. RFID Readers in RFID Circuits have already been experimentally embedded into floor tiles, woven into carpeting and floor mats, hidden in doorways, and seamlessly incorporated into retail shelving and counters, making it virtually impossible for a consumer to know when or if he or she was being "scanned."