A monopulse slot array antenna based on dual-layer substrate integrated waveguide (SIW)

In this paper, a monopulse slot array antenna working at Ka-band based on dual-layer substrate integrated waveguide (SIW) is presented. The 16×16 slot array antenna with feeding network and the monopulse sum-difference comparator is designed on separated layers which takes the advantage of compact size and high aperture efficiency. The honeycomb SIW (HCSIW) is adopted to design the novel right-angle corner and 90 degree 3-dB coupler. The simulated bandwidth (S11 of sum port <; -10 dB) of the antenna is about 9.43%. The maximum gain of sum pattern at 35 GHz is around 26.1 dB with sidelobe suppression of -27 dB in both E-plane and H-plane. This proposed antenna presents a good candidate for the directional-finding systems which are restricted by aperture size.