PURPOSE: To obtain a circuit having almost even frequency response characteristic over a wide range from DC to a high frequency as well as a high impedance, by deciding the resistance voltage dividing point as an output terminal for an output circuit of the coaxial cable.

CONSTITUTION: The voltage dividing main circuit 4 consists of the voltage dividing capacitors 1 and 2 plus resistor 3. For the coaxial cable 5, the center conductor 5a and external conductor 5b are connected to the resistor 3 and the earth respectively. In the output circuit 8, a series circuit comprising the resistors 9 and 10 plus capacitor 7 is connected between the conductor 5a and the earth, and the voltage dividing point Q of resistors 9 and 10 each is connected to the output terminal. In this case, the value of resistor 3 is selected to the characteristic impedance of cable 5, and the value of resistors 9 and 10 are selected to (1-r)R and rR respectively. At the same time, such capacity value is set so that a wide response property is obtained for the step function of C1/C2 times as much as capacity value of capacitors 2 and 7 each to the step function of input.