Broadband and High-Isolation Dual-Polarized Microstrip Antenna With Low Radar Cross Section

A Ku-band dual-linear polarized broadband aperture-coupled antenna with high-isolation and low radar cross section (RCS) in special direction is presented, fabricated, and measured based on substrate integrated waveguide technology. The substrate-integrated rows of metallized via holes (SIRMHs) are inserted into the conventional aperture-coupled antenna to enhance the isolation and improve the impedance matching. Monostatic RCS is reduced because the surface current of the metallized ground plane is guided by the SIRMHs. The theoretical and experimental results are in good agreement. Experimental results indicated that the isolation is more than 40 dB, the bandwidth obtains 21% of return loss less than -20 dB, and the RCS is reduced to as much as 23 dB from 12.2 to 16 GHz compared to a traditional antenna when incident angle is 30 ^°.