System and method for determining whether an object is located within a region of interest

摘要

A system for determining whether an object is within a region of interest includes a radiofrequency signal receiver outside of the region of interest configured to receive radiofrequency signals from the direction of the region of interest; and a radiofrequency transponder having a directional antenna outside of the region of interest and configured to transmit radiofrequency signals away from the radiofrequency signal receiver and towards the region of interest. Presence of an object within the region of interest causes radiofrequency signals transmitted by the radiofrequency transponder to reflect off of the object towards the radiofrequency signal receiver.

主权项

1. A system for determining whether an object is within a region of interest, the system comprising:
a radiofrequency signal receiver outside of the region of interest configured to receive radiofrequency signals from the direction of the region of interest; and a radiofrequency transponder positioned outside of the region of interest, the radiofrequency transponder comprising:
a transponder radiofrequency signal transmitter; anda directional antenna configured to transmit radiofrequency signals away from the radiofrequency signal receiver and towards the region of interest, wherein radiofrequency signals transmitted by the radiofrequency transponder are only received at the radiofrequency signal receiver when the object is within the region of interest because of reflection of the radiofrequency signals off the object.