Abstract: A novel method for enhancing the isolation of dual-linear polarized antenna is proposed based on the aperture coupled structure. The substrate integrated waveguide (SIW) technology is introduced and the substrate integrated cavities (SICs) are used in the aperture coupled and dual-linear polarized antenna to enhance the isolation between two ports in the feeding layer. The capacitive characteristic for the proposed antenna is improved and the imaginary part of the equivalent impedance for the proposed antenna is decreased by embedding the SICs in the four sides of the dual-linear polarized antenna, so that the impedance bandwidth of the proposed antenna is improved. A Ku band dual-linear polarization microstrip antenna is designed by this method to prove the effectiveness of the method and simulated results indicate that the isolation is enhanced above 56％ and the impedance bandwidth is increased above 110％ of the reflection coefficient smaller than -20dB. Experiments are carried out to verify the simulations.

Key words: substrate integrated cavity, dual-polarized antenna, isolation, aperture coupled antenna, impedance marching