In some embodiments, each of antennas 654 and 656 may be fabricated on substrate 652. For example, substrate 652 may comprise one or more conductive layers and each of antennas 654 and 656 may be fabricated on the substrate 652 at least in part by patterning the conductive layer(s). In some embodiments, antenna 654 may be configured to receive RF signals circularly polarized in a first rotational direction (e.g., clockwise) and the antenna 656 may be configured to transmit RF signals circularly polarized RF in a second rotational direction different from the first rotational direction (e.g., counter-clockwise). In other embodiments, however, each of antennas 654 and 656 may be configured to transmit and receive RF signals circularly polarized in the same rotational direction.
In some embodiments, the semiconductor die 658 may be a silicon die, for instance from a bulk silicon wafer or silicon-on-insulator (SOI) wafer. In some embodiments, the die 658 may be a single crystal silicon die. In some embodiments, the die 658 may be a CMOS die, a BiCMOS die, a GaAs die, a GaN die, or may be formed of any other suitable semiconductor material. In the illustrated embodiment, the die 658 is flip-chip bonded to substrate 602. In other embodiments, the die 658 may be wire bonded to the substrate 652 or mounted on substrate 652 in any other suitable way. In the illustrative embodiment of