Ceramic filter for high frequencies

Claim 2

A ceramic three terminal filter for high frequency use comprising: a single piezoelectric ceramic plate and at least two filter elements having mutually different characteristics produced by varying the combined modes of thickness shear vibration, one of said elements having a steeply peaked and narrow-band characteristic and the other having a wide-band and gently slopIng skirt characteristic, said filter elements being electrically connected in series and mounted on said piezoelectric ceramic plate.

Claim 3

The ceramic three terminal filter as claimed in claim 1; in which the piezoelectric ceramic plate has a polarization direction, and the two filter elements comprise respective split electrodes with split directions respectively perpendicular and parallel to said polarization direction, electrical conductors connecting together said split electrodes in series on one surface of said ceramic plate and terminating in two terminals of said filter, and wherein each said filter element is further provided with another electrode attached onto another surface of said ceramic plate in superposed relationship with respect to each said split electrode, said another electrode of both filter elements being connected in series by a lead conductor and attached onto said another surface, one end of said lead conductor terminating in a third terminal of said filter.

Claim 4

A frequency filter comprising: a piezoelectric ceramic plate having a pair of opposed major surfaces and a given polarization direction; a first split electrode on one of said major surfaces comprising two electrode members spaced apart along an axis parallel to said polarization direction; a second split electrode on said one major surface comprising two electrode members spaced apart along an axis perpendicular to said polarization direction; an intermediate conductor electrically interconnecting one member of each said first and second split electrodes; a first conductor electrically connected to the other member of said first split electrode; a second conductor electrically connected to the other member of said second split electrode; and an electrical conductor on the other of said major surfaces including portions superposed in relation to said first and second split electrodes.

Claim 5

A frequency filter comprising: a piezoelectric ceramic plate having a pair of opposed major surfaces and a given polarization direction; a first split electrode on one of said major surfaces comprising two electrode members spaced apart along an axis parallel to said polarization direction; a second split electrode on said one major surface comprising two electrode members spaced apart along an axis perpendicular to said polarization direction; an intermediate conductor electrically interconnecting one member of each said first and second split electrodes; a first conductor electrically connected to the other member of said first split electrode; a second conductor electrically connected to the other member of said second split electrode; and an electrical conductor on the other of said major surfaces including portions superposed in relation to said first and second split electrodes.

Claim 6

A frequency filter according to claim 3; wherein said first conductor, second conductor and electrical conductor each extend to an edge portion of said piezoelectric ceramic plate.

Claim 7

A frequency filter according to claim 3; wherein each of said members is configured as a semicircle.

Claim 8

A three terminal filter device comprising: a piezoelectric plate responsive to electric signal potentials applied thereto to resonate in a thickness shear vibration mode to develop therein a corresponding electric signal, said piezoelectric plate having a pair of opposed major surfaces and a given polarization direction; and conductor means receptive of electric signal potentials during use of the device for applying same to said opposed major surfaces of said piezoelectric plate and receiving therefrom corresponding electric signals developed within said piezoelectric plate and having two interruptions on one of said major surfaces, each said interruptions comprising means defining an elongated space dividing said conductor means into spaced-apart sections, and wherein one of said elongated spaces extends parallel to said polarization direction and the other of said elongated spaces extends perpendicular to said polarization direction.

Claim 9

A three terminal filter device comprising: a piezoelectric plate responsive to electric signal potentials applied thereto to resonate in a thickness shear vibration mode to develop therein a corresponding electric signal, said piezoelectric plate having a pair of opposed major surfaces and a given polarization direction; and conductor means receptive of electric signal potentials during use of the device for applying same to said opposed major surfaces of said piezoelectric plate and receiving therefrom corresponding electric signals developed within said piezoelectric plate and having two interruptions on one of said major surfaces, each said interruptions comprising means defining an elongated space dividing said conductor means into spaced-apart sections, and wherein one of said elongated spaces extends parallel to said polarization direction and the other of said elongated spaces extends perpendicular to said polarization direction.

Claim 10

A three terminal filter device according to claim 6; wherein said conductor means includes an electric conductor mounted on the other of said major surfaces positioned in superposed relationship with respect to both said two interrupted portions.

Claim 11

A three terminal filter device according to claim 7; wherein said conductor means terminates at three locations on edge portions of said piezoelectric plate.