Three-Plane Magnetic Field Detector
Original Publication Date: 1989-Apr-01
Included in the Prior Art Database: 2005-Jan-27
A vector summing circuit for an antenna having three orthogonally disposed windings enables determination of the resultant magnetic vector without antenna rotation nor compromise of signal magnitude, time rate of change or phase relationship. The circuit, shown in Figs. 1a and 1b, uses phase correction, peak-to-peak detection, DC bias control, signal squaring and summing, and determination of signal square root to calculate the resultant magnetic vector. In Fig. 1a, each of three orthogonally disposed antenna coils is attached to a respective one of terminals 1, Xin, Yin or Zin, that each serve as an input to an impedance matching and gain adjustment circuit 2 for the coil and the subsequent circuits.