Integrative Biology

Biography

Biography: Hiroyuki Ito

Abstract

The impulse ultra-wideband (I-UWB) RFID technique has been leading short-range wireless communication technology for body area networks (BAN) and biomedical application due to its abilities of high throughput, low power consumption and so on. However, the issue is that the conventional ultra-low power RF (ULPRF) circuits tend to degrade energy-per-bit (E/B) as the bit rate decreases, although BAN has multimodal application and therefore require a variety of bit rate from kb/s to Mb/s. The main reason is that analog circuits consume large steady current which is not proportional to bit rate, and thus they mainly degrade E/B of transceivers at low bit rate. Especially, RF carrier-signal generation is the challenge. Although accurate RF frequency can be achieved by phase locked loop (PLL) technique, its power consumption can be as large as 1 mW. An impulse transmitter (I-TX) can generate RF signal without PLLs by exploiting delay-based impulse generation technique. The drawback of it is that the gate delay varies over ten times in 65 nm CMOS due to large PVT variation under low supply voltage such as 0.5 V. This paper presents design strategies of ULPRF transceiver systems. We also introduce the prototype I-TX in 65 nm CMOS technology to realize energy-per-bit of 1.5 pJ/bit which is better than previous works showed in the semiconductor top conference. Our TX achieves superior energy-per-bit and ultra-low power operation from 1 kb/s to 10 Mb/s. The proposed received signal strength indicator (RSSI) consumes only 89.5 μW with -85 dBm sensitivity. Our ULPRF technology develops unexplored near zero-power region in lower bit-rate wireless communication, which will contribute to realize battery-less wireless communication for biomedical application.