Patent ID: 7649431
Filing Date: 2010-01-19
Classification: H01P

Abstract:
1. A band pass filter comprising: a ceramic laminated body having at least first to fifth dielectric layers laminated sequentially therein; first and second resonators having symmetrical patterns of first and second inductors formed on the third dielectric layer, and symmetrical patterns of first and second capacitors formed on the second dielectric layer so that they are at least partially overlapped with the patterns of the first and second inductors; patterns of first and second load capacitors electrically capacitively coupled respectively to the first and second resonators formed on the fourth dielectric layer; and first and second ground planes formed respectively on the first and fifth dielectric layers, wherein each of the patterns of the first and second inductors is composed of a low impedance portion formed of wide-width lines and a high impedance portion grounded to the second ground plane and formed of meandering narrow-width lines from the low impedance portion, and tap-shaped input/output terminals directly coupled to input/output electrodes formed on the first dielectric layer are provided in ends of the first and second resonators, respectively.