Super High Frequency Lateral-Field-Excited Aluminum Nitride Cross-Sectional Lamé Mode Resonators

Abstract

This paper reports on the first demonstration of super high frequency (SHF) lateral-field-excited (LFE) aluminum nitride (AlN) cross-sectional Lamé mode resonators (CLMRs). A simple 2-mask process was used to fabricate LFE AlN CLMRs operating at 4.2 GHz with an electromechanical-coupling coefficient kt2 of 1.2 %, providing > 20 MHz filter bandwidth. Anchor loss is reduced to provide 2X higher quality factor (Qm > 1150) implemented with a small termination impedance of 160 Ω. Such important features render AlN LFE CLMRs promising candidates for low-cost yet high-performance wireless communication technologies, such as LTE‐Advanced contiguous carrier aggregation which requires up to 20 MHz bandwidth.