Smart panel for decreasing noise in wide band frequency
The present invention relates to a soundproof panel, and in particular to a smart panel for decreasing a noise in a wide band. The smart panel according to the present invention includes a board structure for decreasing a noise of an audible frequency band, a sound absorption member attached to one surface of the board structure for decreasing the noise of an audible frequency band, and a piezoelectric unit attached to the board structure for decreasing the noise when the same audible frequency as the resonance frequency of the smart panel is propagated for thereby maximizing the insertion loss in the resonance frequency of the smart panel.
1. A smart panel for reducing noise over a wide bandwidth, said smart panel having an audible resonance frequency, comprising:
a pair of board structures which generate noise in an audible frequency band, said board structures being separated by an air layer;
a sound absorption member for decreasing noise generated by said board structures in an audible frequency band, said sound absorption member being attached to a face surface of at least one of said board structures which faces the other one of said board structures; and
a piezoelectric unit attached to an anti-nodal point of each of said board structures for decreasing noise generated by said board structures when said audible resonance frequency is propagated, said piezoelectric units being on face surfaces of said board structures opposite said sound absorption member and air layer, said piezoelectric units comprising a piezoelectric member and a tunable shunt circuit connected with said piezoelectric member for electrically resonating impedance of said piezoelectric member.
2. The smart panel of claim 1 wherein said shunt circuit includes resistive and inductive components.
3. The smart panel of claim 2 , further comprising a plurality of said piezoelectric units each attached to anti-nodal points of one of said board structures on a face surface of said one board structure opposite said sound absorption member.