| 摘要 |
<p>A filter comprising a plurality of resonators (31, 32) coupled to each other electromagnetically, wherein a common multilayer substrate (33) is provided to face one longitudinal end of each resonator (31, 32). The substrate includes interstage circuit elements configuring a filter, and input and output terminals of the filter, and the circuit elements are connected with the resonators. The main surface of the substrate is made to be positioned in a plane orthogonal to the longitudinal axis, and thus the total length of the filter including the resonators and the substrate becomes short. The multilayer substrate can have electrodes for trimming capacitors on its surface, and coil patterns in its inner part.</p> |
