The J-Chip was developed by Micro Talk Systems as a radio-frequency identification RFID race timing solution in accordance with official Track & Fields rules which stated that a person's time is based on when their torso crosses the finish line. The J-Chip timing system can read at a height of 2.0m above the mat. This read height allows for the timing chip to be worn attached to the bib or, in non-Track & Field events, on the wrist instead of on the ankle or attached to the shoe.
In general, a RFID transponder timing systems work using a simple principle. An antenna(s) capable of both sending (triggering) and receiving RF signals is/are placed at a location for the purpose of gathering the identification of participants as they pass the through the checkpoint. The checkpoint equipment transmits a trigger signal through the antenna and transponders within range respond with their unique identification number. This process works using one of many RFID communication protocol which having differing characteristics. When the equipment at the checkpoint receives the identification number, it stores it along with the time and some other information.
Most RFID timing solutions available for the race community were adapted from existing RFID technology to sports timing. RFID technology designed for asset tracking have been the most common to be adapted. The ChampionChip and WinningTime systems both made use of Texas Instruments equipment[1]. A more recent use for this technology is the smart key feature of some automobiles. The modern disposable chips used by ChronoTrack and others were also developed for asset tracking[2][3]. The paper thin format and cheap production process allow for the chip to literally be printed onto a packaging label. This same process can be used to print onto a sticker which can be applied to the back of a bib.
The J-Chip transponder was custom designed for sports timing. It is a active dual frequency tag designed to minimize signal noise and maximize read height and speed. It's use of separate frequencies for sending and receiving reduces the affects of crosstalk interference as well as environmental interference from materials such as metal. The transponder is equipped with a rechargeable battery with a 5+ year lifespan[4].
Since the tag was designed for personal sporting events, it's detection speed is not sufficient for high speed motorized events. However, it has proven to be reliable for running races, marathon, triathlon, cycling, cross-country and downhill skiing, and swimming.