Filter circuit with coupled bulk acoustic wave resonators with impedance matching adaptation

Abstract

The invention provides a filter circuit with coupled resonators comprising: a substrate (100); an acoustic mirror (101) or membrane intended to act as a mechanical support for the acoustic resonators and to isolate these resonators from said substrate; First section (left) comprising an upper resonator (120) and a lower resonator (110) coupled to each other by means of at least one acoustic coupling layer (130), said upper and lower resonators constituting the first section ( A1); a second section (right) comprising an upper resonator (220) and a lower resonator (210) coupled to each other by means of at least one acoustic coupling layer (130), the upper part of the second section and the lower resonator constitute a second section (A2); and a metal via implementing an interstage connection between said lower resonator of one section and said upper resonator of the other section.

Description

Technical field [0001] The invention is an integrated electronic circuit and micro -system in the invention of the body sound wave resonator (BAW). Background technique [0002] The attention of the use of sound resonator is growing with the development of telecommunications, and especially with mobile phones that need to be miniaturized and effective filter circuits.The use of the sound resonator enables high -quality factors in the filter circuit. [0003] Over the past few years, because of its integrated simplicity that its internal quality and SAW (surface sound wave) type resonator cannot provide, the BAW (body sound wave resonator) type sound resonator has produced specific attention to manufacture RF filter circuits. [0004] In addition to its integration in semiconductor circuits, the BAW integrated circuit is particularly concerned due to the multiple combination possibilities provided by the manufacturing complex filter circuit. [0005] The first combination of the s...

AI Technical Summary

Problems solved by technology

[0030] Therefore, not all possible combinations to achieve impedance matching cannot be conceived

[0031] In addition, and this is an even more unacceptable disadvantage: the known CFR structure requires full control over the manufacturing process of the various layers that make up the component to complete

It has been observed in the laboratory that a low dispersion at the level of the electrode layer, the piezoelectric layer and at the level of the coupling layer leads to an unacceptable shift of the resonant frequency of the upper and lower resonators of the same segment, thus irreversible ground causes the filter response to be non-compliant with the desired telecommunication standard (GSM band, UMTS band, etc.), and thus renders the filter unusable

[0032] Here, there are major limitations to the fabrication process of these structures: fabrication is expensive and it may hinder the industrial development of such structures

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