Taper Design for Active Arrays With Maximized EIRP for Bounded Sidelobe Level

Tapering an active array antenna system on transmit lowers the sidelobe level, but it adversely affects equivalent isotropically radiated power (EIRP) by reducing both power and gain. In this article, we analyze this effect. First, we propose a new taper efficiency coefficient, which allows us to assess the effect of tapering on EIRP (in contrast to the standard taper efficiency that describes the effect of tapering on gain only). Then, we present an optimization method to compute the taper weights that maximize the defined efficiency for an assumed bound on the sidelobe level. The obtained optimal weights can be used not only to taper an antenna array but also as a benchmark for other tapers. Therefore, we analyze several known tapers and compare their transmit efficiencies. As a result, we find that for some combinations of sidelobe level and array length, the proposed optimal taper provides substantially better efficiency than Dolph–Chebyshev or Taylor tapers.