Super high frequency width extensional aluminum nitride (AlN) MEMS resonators

Width extensional (WE) super high frequency (SHF) aluminum nitride (AlN) resonators have been fabricated using optical lithography. Solidly anchored WE resonators were shown to be superior to beam anchored resonators of the same size and it was verified that simply scaling resonator area does not improve insertion loss (IL). Resonators with an IL of -6.3 dB into 50 ohms at 4.1 GHz and -7.2 dB at 6.8 GHz have been demonstrated. This type of performance at 6.8 GHz is unprecedented for contour mode resonators and represents a 12.6 dB improvement over recently reported SHF AlN resonators.