Three-axis decoupling stub-loaded parallel dipole array with tri-orthogonal polarization directivity

This paper presents a three-axis decoupling stubloaded parallel dipole array antenna with tri-orthogonal polarization directivity. The decoupling characteristics are realized using the phase shifter composed of a quarter-wavelength stub placed at two sides of three parallel dipole array antenna for creating the opposite phase of the current distribution. Further, the quarter-wavelength stub is operated as an orthogonal dipole antenna due to the in-phase currents enhanced on the stub, leading to the orthogonal directivity. A design example is presented with an antenna separation of 5 mm at 2GHz. The analytical results show that a well-defined isolation and tri-orthogonal polarization directivity can be achieved using the proposed antenna.