Ультразвуковой адаптивный томограф бетонных изделий с нестандартной конфигурацией

It is shown that should be used adaptive antenna arrays, the shape of which can take the form of a non-planar surface of the tested product, for ultrasonic tomography of concrete building structures with a non-standard surface configuration. It should also be used adaptive methods of ultrasound tomography, which allows both to determine the coordinates of defects and the velocity of ultrasound in concrete, as well as adjust the parameters of the probing signals to the characteristics of concrete products.

Prospect for Using Low-Element Adaptive Antenna Systems for Radio Monitoring Stations

This article is devoted to the analysis of prospect to apply multifunctional adaptive antenna systems for radio monitoring stations. The review of publications done demonstrates that current antennas that are developed and used in radio monitoring systems to control and measure the parameters of electromagnetic radiation should be applicable to conduct accurate measurements in wide frequency range under the condition of interferences. The analysis shows that modern adaptive antenna systems are mostly developed for radar and telecommunications applications. In this context we consider possible ways to solve the problem of adapting radio monitoring devices to a complex electromagnetic environment using antenna systems with primary processing of received signals . It was found that the developers of the antennas, which are based on adaptive interference suppression methods, focus basically on the development and implementation of adaptation processes, limiting themselves only to solving electromagnetic compatibility problems. In such approach, the functions of direction finding and measurement of radiation field parameters important exactly for radio monitoring systems are mostly ignored. Therefore, this research area opens up a wide field for identifying new possibilities for constructing multifunctional antenna systems. Focusing on this direction of research, we consider as an example the constraction of a simple two-element adaptive antenna system, which can be used to measure the parameters of the electromagnetic field in radio monitoring systems. The main relations for the error of determining the direction of arrival of the interference signal with a simple two-element antenna are investigated. The influence of the stability of the antenna array parameters and functional units of signal processing onto the errors is estimated.

USE OF ADAPTIVE ANTENNA ARRAYS FOR INCREASE THE THROUGHPUT IN LTE-A

Context. The aim of the article is to analyze the throughput of the LTE-A mobile network on the uplink using an adaptive linear equidistant antenna array. Objective. Suggestions have been made for the possibility of using adaptive antenna arrays to increase bandwidth in LTE-A mobile networks and analyze the benefits of its use compared to the standard type of base station antenna Method. To achieve this result, a computer model of noise analysis of the mobile network in the form of a flat regular hexagonal antenna array consisting of 7 three-sector cells was developed. To estimate the benefit from the use of adaptive antenna arrays, two options were analyzed: when using a standard antenna array of the LTE-A network, and an adaptive linear equidistant antenna array. During the simulation, 100 random placements of subscribers of useful and interference signals were performed and the minimum, maximum and average gain from the use of adaptive antenna arrays was calculated. The average value of the gain for the adaptive antenna array in the direction of the subscriber station, which generates a useful signal of 5.69 dB more than the standard antenna array of the LTE-A network. At the same time, there is a significant reduction in the gain of the adaptive antenna in the direction of the interference subscriber stations, namely, for those with the highest interference level, the gain is 32.84 dB and 28.33 dB, respectively. To clearly show the gain in the qualitative characteristics of the network, a bandwidth analysis was performed for different types of antennas. The bandwidth distribution (transport block size) for 50 resource blocks using an adaptive equidistant linear antenna array compared to a standard antenna array is presented. Results. It is shown that due to the use of adaptive antenna systems, the average bandwidth increases from 11 Mbit/s to 35 Mbit / s for all types of distribution considered channels. Conclusions. The article proposes the use of adaptive antenna arrays to increase the bandwidth of the LTE-A network. The simulation of bandwidth for 50 resource blocks showed that in the presence of internal system interference when using standard antennas of base stations, the average bandwidth is from 11.2 Mbps to 12.3 Mbps. At the same time, due to the use of adaptive antenna systems, the average bandwidth increases from 11 Mbit/s to 35 Mbit/s for all types of multipath channels considered.

Steered Beam Adaptive Antenna Arrays

In this chapter, the performance of steered beam adaptive arrays is presented with its corresponding analytical expressions. Computer simulations are used to illustrate the performance of the array under various operating conditions. In this chapter, we ignore the presence of mutual coupling between the array elements. The principal system elements of the adaptive array consist of an array of sensors (antennas), a pattern-forming network, and an adaptive pattern control unit or adaptive processor that adjusts the variable weights in the pattern-forming network. The adaptive pattern control unit may furthermore be conveniently subdivided into a signal processor unit and an adaptive control algorithm. The manner in which these elements are actually implemented depends on the propagation medium in which the array is to operate, the frequency spectrum of interest, and the user’s knowledge of the operational signal environment.