Abstract: An impedance converter includes an emitter follower constructed of a first transistor with a first resistor connected between an emitter electrode of the first transistor and an output terminal. Input to the emitter follower is provided by a second transistor of complementary type, with input signal applied to the base of the second transistor and the emitter electrode of the second transistor coupled to the base of the first transistor with a second resistor. Bias current in the second transistor and second resistor is in constant proportion to bias current in the first transistor and first resistor. Output impedance can be made positive, negative or zero by appropriate proportioning of the first and second resistors.