As another example of a variation of the embodiments shown in FIG. 9A, there may be one or more filters between any pair of circuits along the signal path from receive antenna 122 to transmit antenna 126. As yet another example, in the embodiment of FIG. 9A receive antenna 122 and transmit antenna 126 are each coupled to signal transformation circuitry 124a using single lines 902 and 914, respectively. However, in other embodiments, one or both of receive antenna 122 and transmit antenna 126 may be differentially coupled to signal transformation circuitry 124a. One such embodiment is shown in FIG. 9B, where both antennas are differentially coupled to the signal transformation circuitry.
In the illustrative embodiment of FIG. 9B, target device 915 includes receive antenna 122, signal transformation circuitry 124b, and transmit antenna 126. Receive antenna 122 is differentially coupled, via lines 916a and 916b, to inputs of signal transformation circuitry 124b. Transmit antenna 126 is differentially coupled to signal transformation circuitry 124b, whereby outputs of signal transformation circuitry 124b are provided, via lines 928a and 928b, to transmit antenna 126. Receive antenna 122 may be any suitable type of receive antenna, examples of which are provided herein. Transmit antenna 126 may be any suitable type of transmit antenna, examples of which are provided herein.
