A high-impedance dual-mode SAW resonator for ultra low power and high data rate FSK modulator

This paper reports on the design and experimental realization of a dual-mode surface acoustic wave (SAW) resonator with two high-impedance resonant peaks for ultra low power binary frequency-shift-keying (FSK) modulator applications. The single-device structure of the dual-mode resonator is believe to be a promising solution to eliminate the loading effect and noise as a result of multiple switches and other parallel connected resonators, and has the potential to reduce the size and complexity of packaging, compared with the multi-resonator multi-frequency approaches. The dual-mode SAW resonator concept is realized by an in-house, two-mask process that delivered symmetric-mode resonators at 404.9 MHz with trans-impedance values of 1,100 Omega and quality factor of 3134, and anti-symmetric mode resonators at 407.6 MHz, with 900 Omega trans-impedance and 4014 quality factors. Based on the experimental results, we propose a FSK modulator that integrates this high-transimpedance dual-mode resonator and reaches data rates up to 1.5 Mbps. The FSK modulator can be used for low power transmitters in body area network (BAN) and wireless sensor networks (WSN). (C) 2014 Elsevier B.V. All rights reserved.