The μ-chip:: An ultra-small 2.45 GHz RFID chip for ubiquitous recognition applications

An ultra-small (0.4 x 0.4 mm(2)) radio frequency identification (RFID) chip named mu-chip has been developed for use in a wide range of individual recognition applications. The chip is designed to be 0.06 mm thick so that it can be applied to paper and to thin paper-like media, which have been used widely in retailing to create certificates that have monetary value, as well as to token-type devices. The mu-chip has been designed and fabricated using 0.18 mum standard CMOS technology with 3-layer aluminum metallization. The chip has a 128-bit memory. The memory data is easily read by applying a 2.45 GHz microwave radio frequency identification circuit technique. The minimum operating voltage of the chip's digital circuits is 0.5 V. This chip has attached to a thin-film external antenna. The chip terminals are connected to the antenna by an anisotropic conductive film (ACF). This type of structure results in a 0.15 rum thin transponder. The maximum communication distance between the mu-chip and a reader is 300 mm at a reader power of 300 mW.