Quadrature RF-Only Logic Family for Single-Chip Self-Powered Transceivers

A single-chip wireless power transfer (WPT) receiver is not only an essential part of the implantable bio-medical devices but also quite popular in the Internet-of-things (IoT) solutions. In the CMOS implementation of a power transfer circuit, an RF-to-DC rectifier is the most inefficient block with respect to power consumption, while the rectifier's storage capacitor takes most of the chip area. In this paper, we introduce a new approach called Quadrature RF-only (QRF-only) logic that operates directly from un-rectified quadrature RF signals. The proposed QRF-only logic eliminates the need for the RF-to-DC rectifier and the related large storage capacitor, thus reducing both the cost and the design complexity of all kinds of single-chip wirelessly powered applications. As a proof of concept, we have designed the QRF- based logic blocks, i.e., inverter, NAND, NOR and D-flip flop. The logic blocks have been fabricated in the 180 nm CMOS technology. By exploiting the inherent adiabatic nature of the proposed logic cells, we have successfully demonstrated that the basic logic and storage functions can be performed with the QRF signals and without a DC power supply. Additionally, the QRF-only logic cells consumed 60% lower power than their classic, static CMOS counterparts.