Current detecting device, impedance measuring instrument and power measuring instrument

摘要

To perform broadband current detection. The current detector of the present invention comprises first terminal, which receives power source current; second terminal, which feeds output current to an outside current; third terminal, which outputs pilot current having a predefined relationship with this output current; and fourth terminal, which has reference potential; as well as first component connected between the first and second terminals; vertical connection of first and second baluns and coupled with the first component; grounded capacitive component at the connecting part of the first and second baluns; and grounded capacitive component at the output part of the second balun. The properties of the instrument for measuring impedance and the apparatus for measuring power are improved by using the current detector of the present invention.