At act 1508, where a second interrogator device (different from the first interrogator device) transmits a third RF signal having the first center frequency to the target device (the same target device to which the first RF signal was transmitted and from which the second RF signal was received). The third RF signal may be of any suitable type and, for example, may be a linear frequency modulated RF signal or any other suitable type of RF signal including any of the types of signals described herein. The third RF signal may have the same center frequency as the first RF signal and may be circularly polarized in the same direction as the first RF signal.