PURPOSE: To avoid a trouble that is caused by the heat expansion or the like, by connecting the high frequency signal of an MIC (IC element of high frequency band circuit) via a waveguide.

CONSTITUTION: The prescribed high frequency signal is transmitted to the projected end part 51 from one MIC5, and thus the high frequency signal is changed to the waveguide mode from the strip line transmission mode at the part 51 to be radiated to the short-circuit line 7 as well as the through-hole 61 of the carrier 6. While the high frequency signal arrived at the projected end part 51' of the other MIC5' is changed to the strip line transmission mode from the waveguide mode to the strip line of the MIC5' and then transmitted to the MIC5.