Miniature on-chip spiral inductor RFID tag antenna fabricated with metal layer of standard CMOS process for biosensor applications

On-chip tag antenna has been designed and implemented for wireless biosensor system based on complementary metal oxide semiconductor (CMOS) integrated circuit. The two types of square shaped on-chip spiral inductors were fabricated with the outermost diameter of 6.3 mm and 3 mm, and innermost diameter of 3.0 mm and 1.5 mm, respectively. The maximum modulation depth values 3.5, and 0.43, were confirmed by the load modulation measurement. The 212 kHz amplitude shift keying (ASK) transmission was shown in pork belly. The chip was fabricated using 1.2 μm standard CMOS technology.