| 摘要 |
A multi-layered band pass filter is provided to improve an attenuation characteristic by adjusting the position of a tap in a resonator. A ceramic laminate is composed of at least first to fifth dielectric layers(101a-101e) sequentially laminated. First and second resonators(Q1,Q2) have first and second inductor patterns(102a,102b) which are symmetrical with respect to each other and are formed at the upper surface of the first dielectric layer(101a), and first and second capacitor patterns(103a,103b) partially overlapped with the first and second inductor patterns(102a,102b) and formed on the second dielectric layer(101b). First and second load capacitor patterns(105a,105b) are electrically capacitive-coupled at the first and second resonators(Q1,Q2) formed at the upper surface of the third dielectric layer(101c). First and second notch capacitor patterns are electrically capacitive-coupled to the other ends of the first and second resonators(Q1,Q2) formed on the upper surface of the third dielectric layer(101c). First and second ground surfaces(107a,107b) are respectively formed at the upper surface of the fourth and fifth dielectric layers(101d,101e). The first and second inductor patterns(102a,102b) are grounded with a low impedance unit(L1a,L2a) which is formed in a wide line, and a high impedance unit(L1b,L2b) which is formed in a narrow line of a meander type from the low impedance unit(L1a,L2a). |
