Monopulse waveguide patch array antenna in 37 GHz band

This paper presents a circularly polarized patch array in 37 GHz frequency, integrated in a narrow band application (BW < 1%) for signal detection. The designed array has to fulfill some specific requirements related to its radiation pattern (monopulse in the horizontal pattern and cosecant shape in the vertical one); other significant requirements are: circular polarization (RHCP with axial ratio under 3 dB), low side lobes (-20 dB below the main lobe) in the sum pattern of the monopulse, and high gain (greater than 32.5 dB)