–Technological advances and developments in solar activities, particularly in solar radio bursts, have created a demand of constructing log periodic dipole antenna (LPDA) to monitor this phenomenon in radio region. In this paper, we make an effort in designing a portable LPDA that suitable with the criteria, specification and practical enough although is the boom length size of the antenna is 3...

An extreamly large scale periodic array antenna is required for transmitting power from space solar power systems. Analysis of the huge-scale array antenna is important to estimate the radiation property of the array antenna, but a full-wave analysis requires too much computer memory and excessive CPU time. In order to overcome these difficulties, the impedance extension method is proposed as a...

In this paper we present the latest developments in the design, fabrication and application of single and arrays of biomimetic hair flow-sensors towards high-resolution air-flow imaging. Redesigning the electrode system of the hair sensor (using SOI wafer technology) has led to improve the detection limit down to 1 mm/s air-flow amplitude using 3 kHz measurement bandwidth. SOI technology facili...

The recoil of atoms in arrays due to the emission or absorption photons is studied for subwavelength interatomic spacing. array interact with each other through collective dipole-dipole interactions and incident laser field low-intensity limit. Shining uniform light on gives rise patterns excitation array. They arise interference different eigenmodes excitation. relation between decay dynamics ...

The concept of connected (or coupled) dipoles in a linear array, which improves wideband performance, is examined. A long wire with multiple feeds is the model, using rigorous moment method analysis. Edge waves of current appear not to be attenuated; around half-wave dipole length the current peaks are one wavelength apart, with deep nulls. For dipole lengths around quarter-wave the current pea...

The regular oscillations in scan impedance (normalized by the infinite array values) that occur across a finite array are uniquely altered in two special cases based on computer simulations of finite-by-infinite arrays. First, dipoles with groundplane at broadside in the E-plane, exhibit a slow modulation of the usual oscillations; the period of the modulation varies with dipole radius. For all...

We consider a lattice gas model with an infinite pairwise nonconvex total interaction of the form V (r) = J r 2 + A cos(2k F ar + φ) r. This one-dimensional interaction might account, for example, for adsorption of alkaline elements on W(112) and Mo(112). The first term describes the effective dipole-dipole interaction while the other one the indirect (oscillatory) interaction; J, A, and φ are ...

Barkhausen noise, including both periodic and aperiodic components, is found in and near the relaxor regime of a familiar relaxor ferroelectric, PbMg1/3Nb2/3O3, driven by a periodic electric field. The temperature dependences of both the amplitude and spectral form show that the size of the coherent dipole moment changes shrink as the relaxor regime is entered, contrary to expectations based on...

The dynamics of a Bose-Einstein condensate is studied theoretically in a combined periodic plus harmonic external potential. Different dynamical regimes of stable and unstable collective dipole and Bloch oscillations are analysed in terms of a quantum mechanical pendulum model. Nonlinear interactions are shown to counteract quantum-mechanical dephasing and lead to phase-coherent, superfluid tra...

Recent experiments have shown that floating ferromagnetic beads, under the influence of an oscillating background magnetic field, can move along a liquid-air interface in a sustained periodic locomotion [Lumay et al., Soft Matter, 2013, 9, 2420]. Dynamic activity arises from a periodically induced dipole-dipole repulsion between the beads acting in concert with capillary attraction. We investig...