Patent ID: 8952768
Filing Date: 2015-02-10
Classification: H03H

Abstract:
1. A BAW resonator with reduced phase and amplitude ripples in a frequency response, the BAW resonator comprising: a substrate having a first side, a second side opposite the first side, and a thickness of 400 μm or less, the second side of the substrate being a polished surface with a peak-to-peak roughness of approximately 1000 A; a Bragg mirror having alternate layers of a high acoustic impedance material and a low acoustic impedance material fabricated on the first side of the substrate; a BAW resonator fabricated on the Bragg mirror; and a lossy material coating the second side of the substrate, the lossy material having an acoustic impedance in the range of 0.01× to 1.0× the acoustic impedance of the layers of high acoustic impedance material.