Нелинейное расщепление линии магнитоупругого резонанса в сильно возбужденном феррите

The nonlinear splitting of magnetoelastic resonance line in powerfully excited ferrite is investigated. It is shown that the amplitude of splited resonance has the same order of value that the amplitude of basis resonance and its frequency is determined by the upper boundary of nonlinear amplitude-frequency characteristic of magnetic system. It is found the threshold character of splitting additional resonance from general. It is determined the possibility of operation of splited elastic resonance frequency by changing of exited magnetic field value which has practical importance.

CPW-Fed Penta Band Monopole Antenna for Multiservice Wireless Applications

A compact triple T-shaped stub with meander loaded strip antenna for penta band applications is proposed. The rectangular patch antenna with meandered and open-ended slot cuts is utilized to realize four operating bands at 2.45 GHz, 3.1 GHz, 5.3 GHz, and 6.5 GHz with an impedance bandwidth of 400 MHz (2.15-2.550 GHz), 1000 MHz (2.7-3.7 GHz), 200 MHz (5.4-5.6 GHz), and 200 MHz (6.4-6.6 GHz), respectively. For an additional resonance frequency, the length of the central T-shaped stub is slightly modified which causes the variation in the current distribution. As a result, the resonance frequency of 5.5 GHz is divided into two resonance frequency bands which are operating at 5.25 GHz and 5.85 GHz with an impedance bandwidth of 100 MHz (5.25-5.35 GHz) and 200 MHz (5.75-5.95 GHz), respectively. Furthermore, a parametric reflection coefficient and surface current distribution analysis is carried out to understand the strip and slot behavior at resonance frequency bands. Finally, a prototype is fabricated and its reflection coefficient, gain, and radiation pattern are measured. The experimental result shows that the proposed antenna is reliable for penta band applications.

Broadband Dual-Polarized Multidipole Antenna for Base Station Applications

A wideband dual-polarized multidipole antenna for base station applications is proposed. It consists of a pair of large square-shaped loop dipoles and a pair of small rectangle loop dipoles as radiation elements. A pair of small rectangle loop dipoles is fed by T-shaped feed structure which is in the large square-shaped loop dipoles radiating arm so that the antenna generates an additional resonance and obtains a wider bandwidth. The proposed antenna was fabricated and measured, and the results show that the antenna achieves a wide impedance bandwidth of 63.7 % with VSWR<1.5 covering the frequency range from 1.55 to 3 GHz. A high isolation is better than 29 dB within the operating frequency bandwidth. Moreover, an average gain 8 dBi and a stable radiation pattern with 3 dB beamwidth of 69° ± 4° at H-plane are obtained.

Bandwidth Enhancement of a Microstrip-Line-Fed Printed Rotated Wide-Slot Antenna Based on Self-Shape Blending Algorithm

This paper proposes a self-shape blending algorithm to improve antenna bandwidth. A printed antenna is designed for bandwidth enhancement based on the proposed algorithm; this approach can also be used to enhance bandwidth in other applications. The antenna completely covers WLAN bands and WiMAX bands after the proposed algorithm is applied. The shape of the rotating slot and the parasitic patch also changes, which excites additional resonance and improves the impedance matching at high frequencies. Test results show that the proposed antenna can work from 2.07 GHz to 5.94 GHz with S 11 ≤ − 10 dB . Compared to a slot antenna without the self-shape blending algorithm, the bandwidth increases by more than 0.7 GHz.

Broadband Modified Proximity Coupled Patch Antenna with Cavity-Backed Configuration

A modified proximity-coupled microstrip patch antenna with broad impedance bandwidth is proposed by incorporating proximity-coupled patch antenna into the rectangular open-ended microstrip feed line on a cavity structure. First we design a proximity-coupled microstrip antenna to have a wide bandwidth in the lower band centered at 7 GHz using a cavity-backed ground. To broaden the bandwidth of the antenna to the upper band, we then apply a rectangular open-ended microstrip feed line, adjusting the relative position to the cavity to generate an additional resonance close to 10 GHz. The combination of lower and upper band design results in a broadband antenna with dimensions of 30 mm × 30 mm × 9 mm (0.9λ₀ × 0.9λ₀ × 0.27λ₀) is designed where λ₀ corresponds to the free space wavelength at a center frequency of 9 GHz. The measurement results verify the broad impedance bandwidth (VSWR ≤ 2) of the antenna at 77% (5.6–12.6 GHz) while the broadside gain is maintained between 6 dBi and 8 dBi within the operational broad bandwidth.

Generalized normal forms of the systems of ordinary differential equations with a quasi-homogeneous polynomial (ax1^2 + x2, x1x2) in the unperturbed part

In this paper a study on constructive construction of the generalized normal forms (GNF) is continued. The planar real-analytical at the origin system is considered. Its unperturbed part forms a first degree quasi-homogeneous first degree polynomial (αx21 + x2, x1x2) of type (1, 2) where parameter α ∈ 2 (-1/2, 0)[(0, 1/2]. For given value of this polynomial is a canonical form, that is an element of a class of equivalence relative to quasi-homogeneous substitutions of zero order into which any first order quasi-homogeneous polynomial of type (1, 2) is divided in accordance with the chosen structural principles due to it only making sense to reduce the systems with the various canonical forms in their unperturbed part to GNF. Based on the constructive method of resonance equations and sets, the resonance equations are derived. Perturbations of the acquired system satisfies these equations if an almost identity quasi-homogeneous substitution in the given system is applied. Their validity guarantees formal equivalence of the systems. Besides, resonance sets of coefficients are specified that allows to get all possible GNF structures and prove reducibility of the given system to a GNF with any of specified structures. In addition, some examples of characteristic GNFs are provided including that with the parameter leading to appearance of an additional resonance equation and the second nonzero coefficient of the appropriate orders in GNFs.

Solar neutrinos as indicators of the Sun’s activity

Opportunity of the solar flares (SFs) prediction observing the solar neutrino fluxes is investigated. In three neutrino generations, the evolution of the neutrino flux traveling the coupled sunspots (CSs) which are the SF source is considered. It is assumed that the neutrinos possess both the dipole magnetic moment and the anapole moment while the magnetic field above the CSs may reach the values [Formula: see text] Gs, display the twisting nature and posses the nonpotential character. The possible resonance conversions of the solar neutrino flux are examined. Since the [Formula: see text] resonance takes place before the convective zone, its existence can in no way be connected with the SF. However, when the solar neutrino flux moves through the CSs in the preflare period, then it may undergo the additional resonance conversions and, as a result, depleting the electron neutrinos flux may be observed.

The Dynamics of Large Systems of Globally Coupled, Mistuned Electromechanical Resonators

While the study of coupled resonant systems is a topic of significant research interest, comparatively little work has been done to study the dynamics of coupled electromechanical systems with many degrees of freedom containing features such as element-level mistuning. In this work we consider the dynamics of a system consisting of a large (N = 16) array of globally coupled, mistuned electromechanical resonators. An analytical and experimental framework is developed to enable the study of emergent behaviors in this system. A number of behaviors are identified, such as the appearance of additional resonance frequencies that are common to all of the resonators in the array. These behaviors are seen in both the analytical model and physical system and are dependent on the global properties of the system, such as the distribution of the parameters of the resonators and the strength of the coupling between the array’s constituent elements.

Bandwidth Enhancement of Microstrip Patch Antenna Using Complementary Rhombus Resonator

By using complementary rhombus resonator (CRR), a small-size and low-profile microstrip patch antenna (MPA) with broad bandwidth has been proposed. Parametric studies were conducted to illustrate the working principle of the proposed antenna. An additional resonance is introduced by the CRR to broaden the bandwidth. Compared with the MPA without the CRR, the bandwidth of the proposed antenna is increased by 200%. The measured results are in good agreements with the simulated ones, which demonstrate that this design provides a way to obtain the broadband antenna.

Depth and Resonance

In this chapter Herodotus’ world is explored as a resonant landscape in three main ways. First, through the human emotions of admiration and wonder generated by Herodotus both in his authorial voice and through characters in the narrative in response to both natural and man-made marvels. Here the multiple focalizations bring complexity through their range of responses. Secondly, depth is brought by the dimension of time, as mythological associations of the landscape are revealed, particularly by the progress of the Persian army through locations famous from myth and epic. Finally, additional resonance is brought by Herodotus’ implicit or explicit drawing of geographical parallels, in which different parts of his world reflect their associations on each other.