Noncontact Measurement Method for High-Frequency Impedance of Load at the End of Wire Harness

摘要

Request for a noncontact measurement method of load impedance connected to a wire harness is increasing rapidly. A method using a network analyzer together with two current probes was previously proposed for this purpose, but it is valid only to 20-30 MHz. In this study, we extended the above-mentioned noncontact measurement method to an FM band by applying a transmission line theory to the wire harness. The validity of the newly proposed measurement method was confirmed experimentally, and as a result the load impedance was measured with an error within 10% up to 100 MHz.