STUDY OF PHASED ARRAYS OF SLOTTED WAVEGUIDE ANTENNAS WITH DIELECTRIC FILLING

Author(s):  
A. O. Pelevin ◽  
A. M. Lerer ◽  
G. F. Zargano

The article describes the computer simulation of phased antenna arrays consisting of slotted waveguide antennas with air and dielectric filling. It is shown that inser-tion of a thin dielectric layer shifts the operating frequency range of phased anten-na arrays by 1 GHz or more down in frequency while maintaining directional char-acteristics.

Antennas ◽  
2021 ◽  
Author(s):  
A. O. Pelevin ◽  
G. F. Zargano

Slotted single-ridge waveguide antenna with dielectric filling has been simulated. Dielectric material has been used to fill the slots, and to form a thin layer directly under the slotted broad wall. The specific pairs of ridge dimensions have been found that provide the same cut-off frequency for an air-filled ridged waveguide as it is for a broader air-filled rectangular waveguide. It has been shown that waveguide ridging followed by insertion of a thin dielectric layer under the slotted wall shift consecutively the antenna operating band down to lower frequencies. The specific values of thickness and permittivity of the dielectric layer suitable for frequency shifting have been found. The simulated characteristics of a 20-element dielectrically filled slotted single-ridge waveguide antenna have been presented. Resultantly, the efficient method of shifting the operating interval of a slotted-waveguide antenna down to lower frequencies has been proposed. The method does not require a broader waveguide, and therefore is effective with respect to low frequency – mass/dimension trade-off.


2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Yadgar I. Abdulkarim ◽  
Halgurd N. Awl ◽  
Fahmi F. Muhammadsharif ◽  
Muharrem Karaaslan ◽  
Rashad H. Mahmud ◽  
...  

Improvement in the antenna gain is usually achieved at the expense of bandwidth and vice versa. This is where the realization of this enhancement can be made through compromising the antenna profile. In this work, we propose a new design of incorporating periodic metasurface array to enhance the bandwidth and gain while keeping the antenna to a low-profile scheme. The proposed antenna was simulated and fabricated in order to validate the results in the operating frequency range from 10 MHz to 43.5 GHz. Computer simulation technology (CST) microwave studio software was used to design and simulate the proposed antenna, while LPKF prototyping PCB machine was utilized to fabricate the antenna. Results showed that the antenna generated a gain and bandwidth of 14.2 dB and 2.13 GHz, respectively. Following the good agreement between the numerical and measurement results, it is believed that the proposed antenna can be potentially attractive for the application of satellite communications in Ku-band electromagnetic wave.


Frequenz ◽  
2016 ◽  
Vol 70 (9-10) ◽  
Author(s):  
Nipun K. Mishra ◽  
Soma Das ◽  
Dinesh K. Vishwakarma

AbstractIn this paper Cylindrical Dielectric Resonator Antenna (CDRA) has been designed for X-band frequency range applications with slot feeding. Bandwidth of designed cylindrical dielectric resonator antenna has been enhanced by making the slot to be resonating and inserting very thin low permittivity dielectric layer between the slot and CDRA. Resonating slot excites the closely spaced HEM


Author(s):  
V. G. Koshkid’ko ◽  
M. M. Migalin

Introduction. Modern antenna devices contain a large number of repeating elements. The process of development of CAD models of such devices requires repeatedly performed operations that is a routine task for an engineer. Therefore, the problem of repeating operations automation arises when constructing antenna models with periodic structures.Aim. To demonstrate the automation of slotted waveguide antennas design process in CAD Ansys HFSS.Materials and methods. In order to determine the dimensions of the slotted waveguide antenna the energy method was used. Automation procedure of the design of the slotted waveguide antennas in CAD Ansys HFSS using the Visual Basic Scripting Edition macros was presented.Results. In order to design and edit slotted waveguide antennas in CAD Ansys HFSS four macros in the VBScript language were established: for slot subtraction from a broad wall of a rectangular waveguide at given coordinates; for removing the original slots created using the previous macro; for drawing a polyline passing through the centers of the slots, in order to verify the antenna’s near field realized distribution; for inclined slot subtraction from a narrow wall of a rectangular waveguide at given coordinates. Results of the macros usage were presented.Conclusion. The above mentioned macros allow one to automate the routine steps during the process of creating and deleting objects while designing an antenna model with periodic structures in CAD Ansys HFSS. Specified procedures for creating macros could be extended to a wide class of tasks related to the studies of characteristics of electromagnetic structures including repeating objects (phased antenna arrays, reflective arrays, slotted waveguide antennas, fractal antennas, log-periodic antennas, multi-layer lens antennas, ladder-type microwave filters).


Author(s):  
A.O. Pelevin ◽  
G.F. Zargano ◽  
A.M. Lerer

The paper simulates the options available to move operating range of slotted waveguide antennas downward in frequency without changing the waveguide cross-section, and suggests the ways for designing linear waveguide-slotted elements based on rectangular and ridge waveguides with air and partial dielectric filling. The critical frequency of the fundamental mode of a 16x8 mm rectangular waveguide moves by ridging from 9.5 to 6.5 GHz. Partial dielectric filling of the cavity of the ridge waveguide makes it possible to additionally shift the operating range downward in frequency by 6-10% without making changes to antenna design. The antenna characteristics of linear arrays based on a dielectric-filled ridge slotted waveguide have been compared in terms of gain and voltage standing wave ratio to similar designs of arrays on rectangular and air-filled analogues. Based on the obtained structures of linear elements, simulation models of planar arrays have been constructed so that they have the similar area of total surface. Simulated frequency dependence of the realized gain for planar arrays has demonstrated a shift of the operating range downward in frequency. The analysis of the directivity characteristics of planar arrays for various phase shifts between the linear elements has been carried out. The simulation results have shown that the use of a dielectric-filled ridge waveguide gives an advantage in phase scan angle of the main beam of the radiation pattern. With the same phase shift, in planar arrays of dielectric-filled ridge waveguides, the main beam scans for a larger angle while keeping side lobes at low level. Thus, the use of a ridge slotted waveguide with a dielectric layer inside makes it possible to expand the phase scan angle.


2020 ◽  
Author(s):  
Shefali Pawar ◽  
Hossein Mehrpour Bernety ◽  
Harry G. Skinner ◽  
Seong-Youp Suh ◽  
Andrea Alù ◽  
...  

Author(s):  
С.М. Фёдоров ◽  
Е.А. Ищенко ◽  
И.А. Баранников ◽  
К.А. Бердников ◽  
В.В. Кузнецова

Рассматривается полуволновый диполь с установленным рефлектором, который позволяет производить сканирование пространства с использованием вращения рефлектора вокруг диполя. Для полученной конструкции производилось моделирование основных параметров, которые показали высокую стабильность при различных положениях рефлектора, постоянное значение коэффициента направленного действия, ширины главного лепестка. Изменение направления излучения совпадает с текущим положением рефлектора. По сравнению с ситуацией, когда у антенны отсутствовал рефлектор, КНД антенны увеличился, так как произошла фокусировка электромагнитных волн. Коэффициент полезного действия и передне-заднее отношение сохраняют высокие значения во всем диапазоне рабочих частот. Применение предложенной конструкции позволяет упростить конструкцию сканирующих антенн, так как для ее реализации требуются лишь полуволновой диполь и плоский рефлектор, установленный на малом расстоянии от источника излучения. В процессе управления характеристиками требуется вращать рефлектор вокруг диполя, при этом диполь остается неподвижным, что позволяет повысить эффективность предложенной конструкции, так как не требуется формировать сложных антенных систем или устанавливать комбинацию из нескольких антенн для фокусировки излучения в одном направлении от источника The article discusses a half-wave dipole with an installed reflector, which allows scanning space using the rotation of the reflector around the dipole. For the resulting structure, we simulated the main parameters, which showed high stability at various positions of the reflector, a constant value of the directivity factor, and the width of the main lobe. The change in the direction of radiation coincides with the current position of the reflector. Compared to the situation when the antenna did not have a reflector, the directivity of the antenna increased since the focusing of electromagnetic waves took place. The efficiency and the front-to-back ratio remain high throughout the entire operating frequency range. The use of the proposed design makes it possible to simplify the design of scanning antennas since the implementation of the proposed design requires only a half-wave dipole and a flat reflector installed at a short distance from the radiation source. In the process of controlling the characteristics, it is required to rotate the reflector around the dipole, while the dipole remains stationary, which makes it possible to increase the efficiency of the proposed design, since it is not required to form complex antenna systems or install a combination of several antennas to focus radiation in one direction from the source


2013 ◽  
Vol 699 ◽  
pp. 251-256
Author(s):  
T. Hisajima ◽  
L. Mao ◽  
K. Shinzato ◽  
M. Nakano ◽  
J. Suehiro

Thispaper reports a novel method to concentrate bacteria in three-dimension by negative dielectrophoretic (n-DEP) force in a microchannel. This was achieved by placing a thin dielectric layer on one of a pair of parallel plate electrodes. The dielectric layer having a home-plate like pentagonal shape, forms a gradient of electric field causing n-DEP. A three-dimensional numerical simulation of bacteria trajectory predicts that bacteria flowing a microchannel were three-dimensionally concentrated beneath the tip of the pentagonal dielectric thin layer. The trajectory and concentration of bacteria under n-DEP force were also experimentally confirmed using Escherichia coli cells. Bacteria moved along edges of the dielectric layer and were pushed to the opposite electrode, resulting in their concentration in three-dimension. The proposed device might be applicable to selective concentration of bacteria depending on their dielectric properties.


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