A simplified technique to estimate the monostatic radar cross section of planar array antennas

The process of modeling and analyzing radar cross section (RCS) can be very complex and very demanding concerning computational efforts. This paper presents a simplified technique to estimate the monostatic RCS of planar array antennas. It is used the APG-73 antenna to buildup and explain the model. The structural and the antenna RCS modes are computed separately. The calculation of the rim contribution (structural mode) is based on uniform asymptotic techniques formulated in terms of the geometrical theory of diffraction (GTD). The antenna mode calculations consider the antenna radiation pattern and the feeders´ characteristics. Results show that in most of the situation the edge diffraction is the foremost backscatter responsible. Some RCS reduction techniques are discussed as well. Finally, this simplified approach shows a good potentiality to allow a reasonable estimate of the behavior of the antenna RCS with low computational effort.