scholarly journals Method for directional pattern adaptation of hydroacoustic antenna array to the current conditions of a non-stationary underwater communication channel

2021 ◽  
pp. 39-47
Author(s):  
P. Unru
Keyword(s):  
Antenna Array ◽  
Communication Channel ◽  
Directional Pattern ◽  
Underwater Communication ◽  
Hydroacoustic Antenna

Гидроакустический канал связи отличается значительной и нестационарной многолучевостью, что делает разработку помехоустойчивой и высокоскоростной гидроакустической системы связи весьма нетривиальной задачей. В работе представлен авторский метод адаптации диаграмм направленности гидроакустических антенных решеток под текущие условия канала. Его новизна – в структуре пилот-сигнала, предназначенного для определения оптимального угла наклона передающей диаграммы направленности, и способе его приема и обработки. Приводятся результаты проведенных автором математического моделирования и экспериментальной оценки эффективности предлагаемого метода.

scholarly journals Bi-Directional Loop Antenna Array Using Magic Cube Origami

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3911 ◽  
Author(s):  
Ying Xu ◽  
Yeonju Kim ◽  
Manos M. Tentzeris ◽  
Sungjoon Lim
Keyword(s):  
Antenna Array ◽  
High Mobility ◽  
Beam Width ◽  
Directional Pattern ◽  
Loop Antenna ◽  
Single Antenna ◽  
Antenna Performance ◽  
Magic Cube ◽  
Half Power ◽  
Peak Gain

In this paper, we propose a bi-directional loop antenna array using magic cube origami. The proposed antenna array consists of three one-wavelength loop antenna elements with series feeding. Each loop antenna is realized on a single magic cube, and three cubes are connected in series to form the array. The three cubes can be easily folded and unfolded due to being constructed in the form of a magic cube origami. Antenna volume can be minimized for high mobility by folding the array, which radiates a bi-directional pattern with full volume when unfolded. The proposed antenna was designed at 1.39 GHz. When the single antenna is realized on the single cube, the peak gain is 4.03 dBi. The peak gain increased to 5.2 and 5.53 dBi with two and three antennas, respectively. Half-power beam width (HPBW) with three antenna elements decreased to 40° from 360° compared to the HPBW with the single antenna. The proposed antenna performance was assessed numerically and experimentally.

scholarly journals Selection of location of radiators in a non-equivident antenna array

2020 ◽  
Vol 8 (6) ◽  
pp. 54-62
Author(s):  
N. M. Legkiy ◽  
N. V. Mikheev
Keyword(s):  
Antenna Array ◽  
Antenna Arrays ◽  
Side Lobe ◽  
Directional Pattern ◽  
Engineering Systems ◽  
Phased Array Antenna ◽  
Optimal Arrangement ◽  
Phased Antenna Arrays ◽  
Calculation Results ◽  
Selection Of

Antennas are one of the main elements of radio engineering systems. Phased antenna arrays (PAR), which make it possible to regulate the direction of radiation due to the ability to control the phases or phase differences of the emitted signal, are the most effective types of antennas. The size, design and shape of the PAR depend on the tasks to be solved, the type of emitters and the nature of their location. The article discusses the transformation of an equidistant PAR into a non-equidistant antenna array in order to reduce the level of side lobes and suppress diffraction maxima with a given minimum distance between the emitters. A model of a non-equidistant antenna array and calculation formulas for its analysis are presented. The method presented in the work based on iterative calculation methods makes it possible to select the main parameters of a non-equidistant PAR taking into account the bonds formed between neighboring radiating elements. The coordinates of the emitter elements of the non-equidistant PAR were calculated in a program using the MATLAB language. At the same time, a method was implemented to search for the optimal arrangement of emitters relative to each other, in which the directional pattern of the antenna array will have a minimum level of diffraction maxima and the required level of side lobe. According to the results of the program execution, the coordinates of the new non-equidistant PAR were obtained. The non-equidistant phased array antenna simulated according to the calculation results showed a complete absence of diffraction maxima, in contrast to the equidistant array, but it was not possible to sufficiently obtain the required level of side lobes. The calculated antenna radiation patterns presented for comparison showed the advantages of a non-equidistant antenn array.

Switched ring antenna array with electronic scanning

Antennas ◽  
2021 ◽  
Author(s):  
V. M. Gavrilov ◽  
R. N. Glukhov ◽  
V. K. Dementiev ◽  
N. N. Korneeva
Keyword(s):  
Antenna Array ◽  
Antenna Arrays ◽  
Side Lobe ◽  
Directional Pattern ◽  
Base Station ◽  
Main Lobe ◽  
Printed Antenna ◽  
Frequency Range ◽  
Beam Position ◽  
Ring Antenna

For operation in the frequency range of 5,1–5,9 GHz, a directional antenna device has been developed for use as part of a base station in a stationary point-to-multipoint system with a controlled beam position. The antenna device is a switched, broadband, ring antenna array with electronic scanning in the azimuthal plane. Its distinctive feature is high gain of the radiating elements, which are used as linear printed antenna arrays with parallel power supply. The required directional characteristics and matching of the emitters have been achieved in the process of parametric synthesis carried out using the CST MS program. In a given frequency range, the emitters are characterized by the following parameters: width of the main lobe of the directional pattern in the E-plane is 6,6…7,5 deg; level of the first side lobe in the E-plane is 0…–11,4 dB; width of the main lobe of the directional pattern in the H-plane is 53,2…73,4 deg; level of the first side lobe in the H-plane is –23,4…–26,4 dB; gain is 17,0…17,5 dB; the reflection coefficient at the input of the emitters does not exceed 0,2. In the horizontal plane the main lobe of the directional pattern at different frequencies is shifted by an angle of 5–10 deg relative to the normal to the radiating opening of the emitters. The reason is a microstrip distributor combined with printed antenna array emitters on a common printed circuit board. The specified offset of the main lobe of the directional pattern does not decrease the functional characteristics of the antenna device, because the difference in level in the direction of the main maximum and in the direction normal to the radiating aperture of antenna arrays does not exceed 0,5 dB. In addition, the specified offset at the given frequency is regular and has the same value for all emitters of the ring antenna array. Therefore, the angular discret and the level of overlap of the directional patterns of the neighboring emitters when scanning in the azimuthal plane remain unchanged. The results of an experimental study of a prototype antenna device have been presented. They are in good agreement with the results of computer modeling.

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