APPLICATION OF THE HILBERT TRANSFORMER FOR SHAPING POLARIZATION-SEPARATED RADIO WAVES OF THE HIGH-FREQUENCY RANGE

Author(s):  
А.Ю. БАРАБОШИН ◽  
Д.В. ЛУЧИН ◽  
Е.Н. МАСЛОВ

Рассматривается способ формирования поляризационно-разнесенных радиоволн ДКМВ-диапазона при организации системы MIMO2^2 с использованием компактных турникетных антенн. Приведены результаты оценки эффективности применения поляризационного разнесения, а также сравнительной производительности и помехоустойчивости предложенного и иных способов организации подобных систем. Показаны преимущества использования разработанного технического решения. A method for the formation of polarization-separated HF radio waves in the MIMO2x2 system using compact turnstile antennas is considered. The results of evaluating the effectiveness of the use of polarization diversity, as well as the comparative performance and noise immunity of the proposed and other methods of organizing such systems are presented. The advantages of applying the developed technical solution are shown.

2015 ◽  
Vol 655 ◽  
pp. 182-185
Author(s):  
Ke Lan Yan ◽  
Run Hua Fan ◽  
Min Chen ◽  
Kai Sun ◽  
Xu Ai Wang ◽  
...  

The phase structure, and electrical and magnetic properties of La0.7Sr0.3MnO3(LSMO)-xAg (xis the mole ratio,x=0, 0.3, 0.5) composite were investigated. It is found that the sample withx=0 is single phase; the samples withx=0.3 and 0.5 present three phase composite structure of the manganese oxide and Ag. With the increasing of Ag content, the grain size of the samples increases and the grain boundaries transition from fully faceted to partially faceted. The permittivity of spectrum (10 MHz - 1 GHz) and the theoretical simulation reveal that the plasma frequencyfpincrease with Ag content, due to the increasing of free electron concentration, which is further supported by the enhancement of conductivity. While for the permeability (μr'), theμr'decrease with the increasing of Ag content at low frequency range (f< 20 MHz), while at the relative high frequency range (f> 300 MHz), theμr'increased with Ag content. Therefore, the introduction of elemental Ag resulted in a higherμr'at the relative high frequency range.


2013 ◽  
Vol 135 (1) ◽  
Author(s):  
P. W. Wang ◽  
D. Q. Zhuang

An impedance-based approach for analyzing an axial rod with shear-type damping layer treatment is proposed. The rod and shear-type damping layer are regarded as two subsystems and both impedances are calculated analytically. The system impedance can be obtained through the impedance coupling between the host rod and the damping layer. The shear-type damping layer is regarded as a shear spring with complex shear modulus. Under the traditional model, the damping coefficient diminishes with the increasing frequency. The paper develops two shear-type damping layer models, including the single degree-of-freedom (SDOF) model and continuous model to predict the behavior of the damping layer. Both damping layer models are compared with the traditional model and the system responses from these models are validated by finite element method (FEM) code COMSOL Multiphysics. Results show that the damping coefficients of both the traditional shear-spring model and SDOF model diminish as the increasing frequency so that the system responses are discrepant with that from COMSOL in the high frequency range. On the other hand, the system response from the continuous model is consistent with that from COMSOL in the full frequency range. Hence, the continuous damping layer model can predict a correct damping coefficient in the high frequency range and this property can be also employed to improve the analysis of the constrained-layer damping treated structures. Finally, the modal loss factor and fundamental frequency of the system with respect to different damping layer thicknesses are presented using the developed approach.


Author(s):  
E.G. Shashkova ◽  
◽  
N.I. Valunets ◽  
M.I. Demidenko ◽  
A.G. Paddubskaya ◽  
...  

Author(s):  
Gongwen Gan ◽  
Dainan Zhang ◽  
Jie Li ◽  
Gang Wang ◽  
Xin Huang ◽  
...  

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