The present invention relates to a gate system which uses overlapping radiation patterns to deduce when an item is entering a warehouse and when an item is leaving a warehouse, for example, for loading onto a truck. The present invention stores information relating to the direction the item moved and actuates an alarm if the item is moved in an unexpected direction. The radiation patterns of the gates are angled such that one radiation pattern from a first antenna is directed towards the loading dock, while another radiation pattern from a second antenna is directed towards the interior of the building. Overlapping the radiation patterns allows the logic circuitry to account for the item as it moves from one side of the gate system to the other.