Patent ID: 8134424

Claim:
A connector for transmitting signals with another electrode portion facing thereto insulated in terms of direct current using electrostatic coupling, comprising: an inner first conductor portion and an outer first conductor portion respectively connected to two signal lines and arranged coaxially; an inner electrode portion having a facing area larger than a cross-sectional area of the inner first conductor portion in a direction perpendicular to a direction of the common axis, and facing the other electrode portion; an outer electrode portion arranged outside the inner electrode portion; an inner second conductor portion for electrically connecting between the inner first conductor portion and the inner electrode portion; and an outer second conductor portion arranged outside the inner second conductor portion for electrically connecting between the outer first conductor portion and the outer electrode portion, wherein a ratio of outer diameter of the inner second conductor portion to inner diameter of the outer second conductor portion is set to provide substantially fixed characteristic impedance at every position of the inner second conductor portion and the outer second conductor portion along the direction of the common axis, and wherein between the inner second conductor portion and the outer second conductor portion is arranged a dielectric in which a dielectric constant of a portion contacting with the outer second conductor portion is smaller than a dielectric constant of a portion contacting with the inner second conductor portion.