Co-Integration of an RF Energy Harvester Into a 2.4 GHz Transceiver Jens Masuch,M e m b e r ,I E E E

Abstract

This paper presents an RF energy harvester em- bedded in a low-power transceiver (TRX) fron t-end. Both the harvester and the TRX use the same antenna and operate at the same frequency of 2.4 GHz. To decouple the harvester from the TRX, different concepts are proposed regarding the transmitter (TX) and receiver (RX). To avoid loading the TX, the harvester i sd e c o u p l e dw i t ha nn M O Ss w i t c ht h a tc a nb ee n a b l e dw i t ha start-up recti fier. Concerning th e RX, the decoupling mechanism relies on the nonlinear input impedance of the main RF-DC converter. The harvester also includes a supply management circuit for over-voltage prote ction and charging energy storage devices with a constant current or voltage. The energy harvester has been co-integrated with the low power TRX in a 130 nm CMOS process and achieves a measured peak power conversion efficiency of 15.9%. For input power levels of at least dBm, it is able to charge up a supply capacitor to a regulated voltage of 1.34 V. The impact of t he harvester on the TRX performance is measured with respect to an identical TRX front-end without harvester, showing little impact on the TRX performance. Both TX output power and R Xn o i s efigure are degraded by less than 0.5 dB. As an additional feature, the start-up recti fier is also used for demodulation of On-Off-Keying (OOK) signaling, which can be used as a second ary wake-up channel. Since the required area for the harvester is only 0.019 mm ( % of the total ac