Enabling Channelizing Filters for High Impedance Nodes with Temperature Compensated Lamb-Wave Resonators

Abstract

This paper presents the development of a narrowband temperature compensated filter that can be embedded in a wake-up radio for improving its sensitivity and robustness. A method for addressing the complexity in achieving the narrow bandwidth and temperature stability simultaneously with aluminum nitride-based lamb-wave acoustic devices is outlined. Using this approach, a theoretical filter is designed with an insertion loss of 6.65 dB and a fractional bandwidth of 0.11% when connected to a port with an impedance of $3\ \mathrm{k}\Omega$ in parallel with 250 fF with a temperature coefficient of frequency of less than 2 ppm/°C first order TCF. The fabricated device shows an insertion loss of 11.5 dB and a fractional bandwidth of 0.13%.