A Wirelessly Powered Reconfigurable FDD Radio With On-Chip Antennas for Multi-Site Neural Interfaces
Hamed Rahmani, Aydin Babakhani
Abstract
This article presents a fully integrated, wireless, RF-powered data transceiver for high-performance implants, such as neural interfaces. The design occupies a total volume of 1.6 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> with no need for an off-chip component. The integrated circuit (IC) receives power and downlink data with amplitude-shift-keying (ASK) modulation by an on-chip coil through an RF wireless link. For uplink data transmission, we designed a transmitter (TX) based on a power oscillator stage directly connected to an on-chip dipole antenna that supports various data rates with both on–off-keying (OOK) and ultrawideband (UWB) schemes. The radio includes a power receiver (RX) system that enables the IC to operate under various power budgets by adjusting the duty cycle of the TX. With a 25-dBm power TX at a 1-cm distance, the RX achieves a maximum data rate of 2.5 Mbps with a power consumption of 2.6 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{W}$ </tex-math></inline-formula> . Also, the TX supports data rates of up to 150 Mbps with UWB modulation with a 15-cm operating range achieving an energy efficiency of 4.7 pJ/b. This work improves RX and TX energy inefficiencies by <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times 50$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times 2.3$ </tex-math></inline-formula> , respectively.