| 摘要 |
A ground pattern of a printed circuit board of an electronic instrument is connected with a conductive part of a housing of the instrument by a series combination of components respectively having the inductive nature and capacitive nature, or by a series combination of components respectively having the resistive nature and capacitive nature, or by a series combination of components respectively having the inductive nature, capacitive nature, and resistive nature. In this way the impedance can be adjusted against frequency so as to be ready for the frequency where the standing wave appears, the resonance frequency of LC series circuit, and harmonic frequencies of electric current flowing on the circuit board. In another arrangement, the ground pattern of a printed circuit board is connected with the conductive part of the housing of instrument through a plurality of separate connection paths with different impedances.
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