Systems and methods are disclosed for the co-location of radio frequency (RF) antennas in portable devices, portable devices and their docking stations and related systems, and devices with restrictive space constraints to allow for simultaneous receive (RX) and transmit (TX) operation without degradation. The systems and methods disclosed overcome RX channel degradation, receiver performance, and other problems seen in prior solutions. More particularly, transmit and receive antennas are oriented to provide for cross-polarization of their electro-magnetic fields, are oriented to allow one or both antenna to fall within null regions of the other antenna, and/or oriented with both cross-polarization and null region considerations in mind. Other variations and implementations are also described.