This paper shows that an optimal antenna pattern for active phased array synthetic aperture radar (SAR) has been synthesized to meet the best performances based on particle swarm optimization (PSO) and adaptively selected weighting factors. Because the antenna radiation pattern has a very close relation with the performance of an active phased array SAR system, the authors derived the multi-obj...

The use of piezoelectric wafer active sensors (PWAS) phased arrays for Lamb wave damage detection in thin-wall structures is presented. The PWAS capability to tune into specific Lamb-wave modes (which is an enabling factor for our approach) is first reviewed. Then, a generic beamforming formulation that does not require the conventional parallel-ray approximation is developed for PWAS phased ar...

A linear array radar can be operated as a multiple-input multiple-output (MIMO) radar or a directed beam radar. A MIMO radar transmits orthogonal waveforms on each array element, which can achieve virtual aperture extension. Compared to a directed beam radar, MIMO radar requires longer integration times to maintain the same energy on target. This results in narrower Doppler bins but increased r...

Phased array antennas are deployed in electronic systems where high beam directivity and/or electronic beam scanning is desired in applications ranging from radar systems to smart antennas in wireless communication where errors such as random and/or correlated fluctuations present in the excitation coefficients of a phased array can degrade its performance. The errors due to random environmenta...