| 摘要 |
The inventive bandpass filter is suitable for use in a multi-layer ceramic (MLC) structure. Specifically, the filter is a semi-lumped type, formed by lumped capacitors and distributed transmission lines. Preferably, shorted transmission lines are used as equivalent inductors, which are connected with high value lumped capacitors to form resonators. Accordingly, the size of the resonators can be much smaller than +E,fra 1/4+EE of the signal wavelength. The bandpass filter preferably has attenuation poles very close to lower passband edge, which results in a very sharp rejection near the stopband. The inventive filter may be utilized as a receiver-end filter in, e.g., duplexer applications or for miniaturized applications, such as portable communications.
|
