Half mode substrate integrated waveguide cavity backed antenna with low cross-polarization

Abstract

A new model of half-mode substrate integrated waveguide (HMSIW) cavity backed antenna with low cross-polarization is characterized here. The HMSIW cavity is achieved by intersecting the rotated rectangular substrate integrated waveguide (SIW) cavity across the hypothetical magnetic wall, and transfigure into non-radiating cavity to radiating aperture without applying any radiating slot. Using this technique the size of SIW cavity is reduced 50% over conventional SIW cavity. The proposed antenna is feed by 50Ω GCPW line. Impedance bandwidth of proposed antenna is 2.5% (9.9 GHz-10.15 GHz) over −10 dB reflection coefficient. Gain and radiation efficiency are more than 7.3 dB and 98 % in impedance band. The low cross-polarization level is below 45 dB over co-polarization and high front to backed ratio (FBR), which is more than 25 dB at mid band frequency.