Structure characteristic impedance estimator using current probe

摘要

A method for estimating the characteristic impedance of a structure comprising the following steps: providing a current probe comprising a magnetic core having an aperture therein and a primary winding wrapped around the core; measuring, with a calibrated vector network analyzer (VNA), the impedance (Zop) of the current probe while in an open configuration wherein nothing but air occupies the aperture and the current probe is isolated from a ground; measuring, with the VNA, the impedance (Zsh) of the current probe while in a short configuration, wherein the current probe is electrically shorted; measuring, with the VNA, the impedance (Zin) of the current probe while the current probe is mounted to the structure such that the structure extends through the aperture; and calculating an estimated characteristic impedance (Z′mast) of the structure according to the following equation: Z′mast=(Zin−Zsh)(Zop−Zsh)/(Zop−Zin).

主权项

1. A method for estimating a characteristic impedance of a structure comprising the following steps:
providing a current probe comprising a magnetic core having an aperture therein and a primary winding wrapped around the core; measuring, with a calibrated vector network analyzer (VNA), an open impedance (Zop) of the current probe while the current probe is in an open configuration wherein nothing but air occupies the aperture and the current probe is isolated from a ground; measuring, with the VNA, a short impedance (Zsh) of the current probe while the current probe is in a short configuration, wherein the current probe is electrically shorted; measuring, with the VNA, an input impedance (Zin) of the current probe while the current probe is mounted to the structure at a location A on the structure such that the structure extends through the aperture; calculating an estimated characteristic impedance (Z′mast) of the structure at location A according to the following equation: Z′mast=(Zin−Zsh)(Zop−Zsh)/(Zop−Zin); and clamping an impedance-matched current probe to the structure at location A to create a mast clamp current probe (MCCP) antenna.