| 摘要 |
PROBLEM TO BE SOLVED: To facilitate the filter characteristic adjustment work and to increase the work speed without an influence of other resonance circuits upon one resonance circuit which is being adjusted. SOLUTION: The characteristic of a filter having resonance circuits Z1 and Z2 is adjusted. Resonance circuits Z1 and Z2 are electrically coupled to each other and have variable impedance elements Z12 and Z22, and one of two circuit elements is connected to ground conductors T11 and T21. The other is connected to an input terminal IN or an output terminal OUT through parallel circuits consisting or impedance elements Z13 and Z23 and short-circuit circuits SC1 and SC2. In the resonance circuit Z1, a characteristic measuring instrument 2 is connected to the input terminal IN, and the ground terminal T11 is grounded and in the resonance circuit Z2, the output terminal OUT and the ground terminal T21 are end. In this state, the variable impedance element Z12 included in the resonance circuit Z1 is adjusted to adjust the characteristic of the resonance circuit Z1. |
