Ricerc@Sapienza

An annular periodic leaky-wave antenna (LWA) fed by a simple azimuth-symmetric source is designed to generate a high-gain omnidirectional conical beam pattern which scans with frequency over a wide angular range. The proposed structure is defined by a finite metallic radial strip grating printed on a grounded dielectric slab which supports an n = 0 cylindrical leaky wave (CLW) mode. The distinctive features of CLWs supported by such a truncated structure are also highlighted and discussed.

In this paper, a novel Full Reference method is proposed for image quality assessment, using the combination of two separate metrics to measure the perceptually distinct impact of detail losses and of spurious details. To this purpose, the gradient of the impaired image is locally decomposed as a predicted version of the original gradient, plus a gradient residual. It is assumed that the detail attenuation identifies the detail loss, whereas the gradient residuals describe the spurious details.