In this paper, a multi-objective approach is applied to the design of aperiodic linear arrays of antennas. The adopted procedure is based on a standard Matlab implementation of the Controlled Elitist Non-Dominated Sorting Genetic Algorithm II. Broadside symmetrical arrays of isotropic radiators are considered with both uniform and non-uniform excitations. The work focuses on whether, and in whi...

The problem of quantizing a circularly-symmetric complex Gaussian random variable is considered. For this purpose, we design two non-uniform quantizers, a high-rate-, and a Lloyd-Max-, quantizer that are both based on the (golden angle) spiral-phyllotaxis packing principle. We find that the proposed schemes have lower mean-square error distortion compared to (non)-uniform polar/rectangular-quan...

A new concept to design thin directional broadband antennas on EBG or HIS surfaces is proposed. Using our proposed concept an octave or more bandwidth is obtained with fairly thin EBG structures even at UHF frequencies allowing low profile antenna design and development. At the heart of the proposed scheme lies the concept of a non-uniform aperiodic EBG surface where the EBG patch size and thei...

Thermal transducers, which can be interpreted as thermally actuated compliant mechanisms, have found a wide range of applications, due to the reason of accessible source, easy controllability and reliability. During the past decade topology optimization techniques have been developed as efficient tools to design distributed type of complaint mechanisms. The generated results have been accepted ...

A design method for causal bi-orthogonal PR FIR M -band filter banks is described, which allows an explicit control over system delay, independent of the filter length, with the lowest possible delay equal to the blocking delay of M 1 samples. The design method is very general and can be applied to non-uniform filter banks but also treats uniform modulated filter banks as a special case.

In this article, small scale effects on free vibration analysis of non-uniform nanobeams is discussed. Small scale effects are modelled after Eringen’s nonlocal elasticity theory while the non-uniformity is presented by exponentially varying width among the beams length with constant thickness. Analytical solution is achieved for free vibration with different boundary conditions. It is shown th...