Timed arrays of spiral antennas for circularly polarised UWB scanned patterns with low side lobes

This research presents a novel design of a timed antenna array of two‐arm log spiral antennas. The design consists in optimising the non‐uniform antenna positions in order to obtain a scanned energy pattern with low side lobes in time domain. It is utilised the well‐known sequential quadratic programming for the optimisation. The non‐uniform array is compared with conventional geometries, such as square array and concentric ring array. The resulted timed antenna array is also analysed in frequency domain after the optimisation in time domain. The results revealed good performance of the non‐uniform timed antenna array for ultra wide band, circular polarisation, beam scanning and low side lobes.