Performance evaluation of RF beamforming based on a wideband antenna array and photonic true time delay

A generalized pattern multiplication method to evaluate the performance of a photonic true time delay (TTD) based wideband antenna array is proposed, by which the wideband radiation pattern of the antenna array can be calculated if the spectrum of the feeding signal and the radiation pattern of every antenna element under different frequencies are given. Based on the proposed method, a simulation study of one-dimensional uniform linear array with ideal photonic TTDs is carried out. Results show that the photonic TTD-based beamformer together with a wideband linear frequency-modulated (LFM) feeding signal can effectively suppress the grating lobes.