US 7,538,638 B2
	Resonator, filter, and communication unit
Seiji Hidaka, Nagaokakyo (Japan); and Shin Abe, Muko (Japan)
Assigned to Murata Manufacturing Co., Ltd., Kyoto-fu (Japan)
Appl. No. 10/558,158 PCT Filed Mar. 10, 2004, PCT No. PCT/JP2004/003062 § 371(c)(1), (2), (4) Date Nov. 23, 2005, PCT Pub. No. WO2004/114455, PCT Pub. Date Dec. 29, 2004.
Claims priority of application No. 2003-173745 (JP), filed on Jun. 18, 2003.
Prior Publication US 2007/0013465 A1, Jan. 18, 2007
Int. Cl. H01P 1/20 (2006.01)

U.S. Cl. 333—202  [333/219.1]

19 Claims

1. A stepped impedance structured resonator comprising: a laminate having superposed set of first, second and third layers; the second layer which is disposed between the first and third layers being a dielectric; each of the first and third layers being conductive layers having spaced first and second non-conductive areas with a first conductive area therebetween; a portion but less than all of the first non-conductive areas of the first and third layers overlapping in the lamination direction and a portion but less than all of the second non-conductive areas of the first and third layers overlapping in a lamination direction to thereby form inductive areas; and a portion of the first conductive areas of the first and third layers overlapping in the lamination direction to thereby form a capacitive area, wherein the shape of the first non-conductive areas of the first and third layers perpendicular to lamination direction are different.