PURPOSE: To prevent deterioration in the characteristic by providing a notch to a connecting face of a carrier plate of a unit microwave integrated circuit and providing a conductive elastic body in contact with the notch so as to improve the coupling of the carrier plate of each unit microwave integrated circuit.

CONSTITUTION: A space whose cross section is a triangle is formed by the notch 10 of the carrier plates 1 connected mutually and the bottom of a package 6 and a cylindrical phosphor bronze plate 11 is placed so as to be in contact with said space. Since the cylindrical phosphor bronze plate 11 is adhered closely to the upper face of each carrier plate 1 fixed through the connection above with a pressure due to deformation, the microwave current flowing to the surface of the carrier plates 1 flows as if it were flowed on one surface of the carrier plates 1, then the microwave currents flowing to the connected carrier plates are summed mutually in terms of microwave excellently. Thus, the flowing of the microwave current at the connecting point of each unit microwave integrated circuit is made smooth so as to decrease the reduction in the characteristic.