A Figure of Merit for Simultaneous-Multi-Beam Transmit Antenna Arrays

Antenna arrays capable of transmitting multiple beams simultaneously are a recent innovation which offers increased functionality and performance over conventional array systems. We present a simple and useful figure of merit (FoM) to evaluate the performance of simultaneous-multi-beam (SMB) transmit (TX) antenna arrays. The FoM builds upon the power-aperture product and effective isotropic radiated power for single-beam arrays and extends it to SMB arrays. The FoM is the product of radiated power, antenna aperture efficiency and the amplifiers power added efficiency. We compute the FoM for three different two-beam TX systems to highlight the usefulness of the FoM. It enables systematic comparison of modern and future multi-beam radar and communications arrays.