Wireless communication system and method with elliptically polarized radio frequency signals

Abstract

In one embodiment, a UWB transmission system includes a pair of crossed linearly polarized antennas, one of which is fed with a UWB signal current, while the second is fed with a temporally orthogonal UWB signal such as the time-derivative of the UWB signal current. The resultant field is elliptically polarized. In another transmission system, a loop and a co-located dipole are fed with the same current to generate signal exhibiting elliptical polarization. When the energies of the transmissions from each antenna are equal, the polarization is circular. In yet another embodiment, a polarization modulated transmitting and receiving system is disclosed in which the binary states are encoded in orthogonal polarizations, wherein left-handed polarization encodes one digital state while right-handed polarization encodes another digital data state, and data encoding is additionally provided. Since either one circular polarization state can be generated with both UWB pulses flipped in polarity, a Polarization Orthogonal Keying (POK) modulation, of 4-state per symbol in the two orthogonal polarizations is disclosed as one example. Thus a UWB transmitting and receiving system is shown that utilizes signals that are simultaneously spatially orthogonal and temporally orthogonal, and the several combinations of those signal and polarization states encode data for transmission.