| 摘要 |
PROBLEM TO BE SOLVED: To effectively miniaturize a laminated type dielectric filter whereas realizing balanced inputs/outputs, with considering the connection of high-frequency amplifier circuits, etc. SOLUTION: The filter is composed of filter parts 20, having first and second input resonance electrodes 16a, 16b and first and second output resonance electrodes 18a, 18b forming two quarter-wavelength resonators in a circuit board 14, transformers 28 having a plurality of striplines 22, 24, 26 and connections 30 for connecting the filter parts 20 with the transformers 28. The filter parts 20 are formed on the upper sides of dielectric layers in the laminating direction, the transformers 28 are formed on the lower sides in the laminating direction, and the connections 30 are formed between the filter parts and the transformers 28. |
