A multi-coil antenna array constructed with a tuned transformer to null
mutual inductance. First and second antenna coil halves are displaced
longitudinally on opposite sides of a pathway along which ID tags pass,
for example, a chute assembly. The planar coils are displaced at a
selected angular orientation and driven with inputs having a 90.degree.
phase differential to create an intermediate vertical field with a
vertical axis of rotation. Identification data stored in tags attached to
animate or inanimate objects passing through the field is interrogated,
such as data identifying people, animals, inventory or any other
parameters of interest.