I am publishing a new concentric co-planar coil with strong magnetic field for metal detectors. Former concentric co-planar coils consist of relative small receive (RX) and bucking (canceling) coil. So the magnetic field density over the flux area of the RX coil was highly cancelled by the bucking coil. This new design enables lower canceling the magnetic field density on the center position of the coil arrangement. Also the relative big RX coil covers much more detection area. The hot spot of the coil (max. sensitivity position) is on the center position of the coil arrangement. The main transmit coil (TX) is on the center position of the coil. The bucking (canceling) coil is outside or on the same core of the RX coil. The main magnetic field is provided by the TX coil.
See magnetic field cross section and the coil arrangement on the following link:
By issue date and time and the publishing this type of concentric co- planar coil, it isn't anymore possible to patent my invention. So it isn't novel anymore now. Take this coil for de-mining. It is a gift for mankind.
Rosenheim, 9. April 2008, Aziz =D6g=FCt