PURPOSE: To prevent the reduction in a return loss by providing a capacitive element connected to the ground to cancel an inductive component of the 1st and 2nd connection lines connected in series at the connecting point of the 1st and 2nd connection lines connected in series.

CONSTITUTION: A grounding capacitive element 5 is connected to the connecting point between the 1st and 2nd connection lines 3, 4 connected in series. Thus, it is possible to cancel the inductive component of the 1st and 2nd connection lines 3, 4 connected in series by the capacitive component 5. Thus, even when the length of the connection wire between microwave integrated circuit modules is prolonged to some extent depending on the mounting condition, the deterioration in the return loss is suppressed.