Multimode substrate integrated waveguide H-plane monopulse feed

A structure for an optimum monopulse feed is proposed at Ku-band using a muftimode substrate integrated waveguide (SIW). A 180deg directional coupler is employed to realise the in- or out-of-phase feeding mechanism, and an H-plane moder is used to generate the odd and even illumination laws at the aperture. A horn antenna is constructed from the dielectric substrate and three other copper plates to radiate energy effectively. All parts have been fabricated in a normal PCB process. Good agreement between the simulation and measurement is observed, which certifies that this type of SIW monopulse feed is feasible and has good characteristics.