PURPOSE: To sum up periodic spurious waves in opposite phase to offset them each other and to save a spurious radiation by varying the wire connection position of a reference potential point with each cross length weighted type transducer.

CONSTITUTION: A signal vi inputted from a signal source 4 to, e.g., a transducer 1 in the connection A uses a reference potential point as an electrode terminal P1. Then the signal vi is inputted to a transducer 3 via a multi-strip coupler 2. Then the signal vi is sent to a load 5 via electrode terminals P3, P4 and the reference potential point of a signal vo to the load 5 is electrode terminal P4. An electrode terminal P2 is the reference potential point for the signal vi, the signal vo uses the electrode terminal P4 as the reference potential point in the connection B. An electrode terminal P1 is the reference potential point for the signal vi, the signal vo uses the electrode terminal P4 as the reference potential point in the connection C. An electrode terminal P1 is the reference potential point for the signal vi, the signal vo uses the electrode terminal P3 as the reference potential point in the connection D. The spurious radiation is offset by combining the four cases above properly.