A mm-Wave Power-Harvesting RFID Tag in 90 nm CMOS

A mm-wave power-harvesting RFID tag is implemented in 90 nm CMOS. Operation at mm-wave reduces antenna size and could allow antenna integration on-chip. This, together with power harvesting that can be used in lieu of a battery, can result in a pinless, CMOS-only tag with no package and no off-chip components whatsoever. The tag harvests energy from the incoming mm-wave continuous wave (CW) signal transmitted by the reader and then uses a 60 GHz free-running oscillator to transmit back pulse-width modulated bursts. An in-depth treatment of the voltage multiplier and associated matching network and implications on tag range are presented. With 2 dBm mm-wave input power, the tag achieves a rate of 5 kb/s. The RFIC size is 1.3 × 0.95 mm² including pads.