Optimal Acoustic Impedance Materials for Polished Substrate Coating to Suppress Passband Ripple in BAW Resonators and Filters

A bulk acoustic wave (BAW) resonator is constructed to reduce phase and amplitude ripples in a frequency response. The BAW resonator is fabricated on a substrate 400 mum thick or less, preferably approximately 325 mum, having a first side and a polished second side with a peak-to-peak roughness of a...

Ausführliche Beschreibung

Gespeichert in:

Bibliographische Detailangaben
Hauptverfasser:	HANNAN MASUD, GODSHALK EDWARD MARTIN, WALL RALPH N, SRIDHAR UPPILI, LUTZ RICK D
Format:	Patent
Sprache:	eng
Schlagworte:	BASIC ELECTRONIC CIRCUITRY ELECTRICITY IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS RESONATORS
Online-Zugang:	Volltext bestellen
Tags:	Tag hinzufügen Keine Tags, Fügen Sie den ersten Tag hinzu!

Beschreibung
Zusammenfassung:	A bulk acoustic wave (BAW) resonator is constructed to reduce phase and amplitude ripples in a frequency response. The BAW resonator is fabricated on a substrate 400 mum thick or less, preferably approximately 325 mum, having a first side and a polished second side with a peak-to-peak roughness of approximately 1000 A. A Bragg mirror having alternate layers of a high acoustic impedance material, such as tungsten, and a low acoustic impedance material is fabricated on the first side of the substrate. A BAW resonator is fabricated on the Bragg mirror. A lossy material, such as epoxy, coats the second side of the substrate opposite the first side. The lossy material has an acoustic impedance in the range of 0.01× to 1.0× the acoustic impedance of the layers of high acoustic impedance material.