A Power-Harvesting Pad-Less Millimeter-Sized Radio

A wireless-powered pad-less single-chip radio is implemented in 65 nm CMOS for applications in Internet of Things (IoT) and wireless tagging. This fully-self-sufficient mm-wave radio has no pads or external components (e.g., power supply), and the entire radio is a single chip with dimensions of 3.7 mm by 1.2 mm. To provide multi-access, and to mitigate interference, it uses two separate mm-wave bands for RX/TX and integrates both antennas to provide a measured communication range of 50 cm. The transmitter uses a modified Multipulse Pulse Position Modulation (MPPM) with 2 GHz of bandwidth on a 60 GHz carrier to communicate the data sequence as well as the local timing reference. The entire system operates with standby harvested power below 1.5 μW and achieves an aggregate data rate > 12 Mbps.