In some embodiments, the circuitry shown within block 1462 may be implemented as integrated circuitry integrated with a semiconductor die. However, in other embodiments, one or more components within block 1462 may be implemented not on a semi-conductor die (e.g., as a discrete component on a PCB) and/or one or more components not within block 1462 may be implemented as integrated circuitry on a semiconductor die (e.g., loop filter 1312). It should be appreciated, like interrogator 1404, the receive-only interrogator 1434 does not include either transmit circuitry or a transmit antenna. As discussed above, this may reduce the cost of manufacturing, the size, and the power consumption of the receive-only interrogator relative to an interrogator device that performs both transmit and receive functions.