Pulse shape optimization in time-modulated arrays for sideband radiation suppression

In time-modulated arrays, the signal transmitted or received by the array elements is multiplied by means of a train of periodic pulses which allow to obtain an angularly selective radiation pattern at the antenna working frequency. Generally, a set of radio-frequency switches is used for the pulse generation and it is assumed that ideal rectangular waveforms are obtained. In this work, pulse waveforms having non-instantaneous on-off transitions are taken into account and their shapes are optimized by means of a stochastic global algorithm in order to reduce the losses in the sidebands caused by the time modulation process.