In recent years, active periodic structures with in-time modulated parameters have drawn ever-increasing attention due to their peculiar (and sometimes exotic) wave propagation properties. Although many experimental works shown the efficacy of time-modulation strategies, benchmarks proposed until now been mostly proof-of-concept demonstrators, little feasibility solution for practical purposes....

In this paper various layered planar periodic structures which provide miniaturization of planar antennas are proposed and discussed. The proposed designs are based on two concepts, reactive impedance surfaces and complementary periodic structures. In the proposed structures, complementary periodic rings and slots are patterned on the intermediate boundaries of the dielectric layers. A patch an...

An eigenvalue method is developed for analyzing periodic structure in speech. Signals are analyzed by a matrix diagonalization reminiscent of methods for principal component analysis (PCA) and independent component analysis (ICA). Our method—called periodic component analysis ( CA)—uses constructive interference to enhance periodic components of the frequency spectrum and destructive interferen...

The properties of nuclear matter are studied in the framework of quantum hadrodynamics. Assuming an o-meson field, periodic in space, a self-consistent set of equations is derived in the mean-field approximation for the description of nucleons interacting via U-meson and w-meson fields. Solutions of these self-consistent equations have been found: The baryon density is constant in space, howeve...

Periodic structures are well known in various branches of physics for their ability to provide a stopband. In this article, using optical periodic structures we showed that, when a second periodicity--very closed to the original periodicity is introduced, large number of states appears in the stopband corresponding to the first periodicity. In the limit where the two periods matches, we have a ...

The structure of eigenstates for the ensembles of standard and periodic Band Random Matrices (BRM) is analysed. The main attention is drawn to the scaling properties of the inverse participation ratio and other measures of Iocahzation Iength. Numerical data are compared with analytical results recently derived for standard BRMS of