scholarly journals DESIGN OF ANTENNAS FOR HYBRID FSO/RF TRANSMISSION SYSTEM

2021 ◽  
Vol 21 (2) ◽  
pp. 28-33
Author(s):  
Maroš LAPČÁK ◽  
◽  
Ľuboš OVSENÍK ◽  
Jakub ORAVEC ◽  
Norbert ZDRAVECKÝ
Keyword(s):  
High Efficiency ◽  
Horn Antenna ◽  
High Gain ◽  
Transmission System ◽  
Helical Antenna ◽  
Rf System ◽  
Horn Antennas ◽  
Narrow Width ◽  
High Level ◽  
Radiation Angle

The purpose of this publication is to create and correctly analyse a secondary RF line for a hybrid FSO/RF system. Since we want to ensure almost 100% functionality, the design of a secondary RF line is very important. In our case, we have chosen two types of antennas. First, it was a helical antenna that achieves a high level of efficiency and much smaller dimensions compared to horn antennas. The second type was just a horn antenna. Its advantages are high efficiency, high gain, and narrow width of radiation angle. However, large disadvantages are dimensions and the price of these antennas. However, in both cases, we can say that these antennas are suitable for deployment to our hybrid FSO/RF system.

scholarly journals A Compact Vivaldi Shaped Partially Dielectric Loaded TEM Horn Antenna for UWB Communication

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Mustafa İlarslan ◽  
A. Serdar Türk ◽  
Salih Demirel ◽  
M. Emre Aydemir ◽  
A. Kenan Keskin
Keyword(s):  
Communication Systems ◽  
Horn Antenna ◽  
High Gain ◽  
Simulation Software ◽  
Antenna Structure ◽  
Horn Antennas ◽  
Compact Antenna ◽  
Uwb Antennas ◽  
Tem Horn ◽  
Uwb Applications

Ultrawideband (UWB) antennas are of huge demand and Vivaldi antennas as well as the TEM horn antennas are good candidates for UWB applications as they both have relatively simple geometry and high gain over a wide bandwidth. The aim of this study is to design a compact antenna that achieves maximum gain over a bandwidth between 1.5 and 10.6 GHz while minimizing its size. The idea is to make use of combined respective advantages of Vivaldi and TEM horn antennas to achieve the desired goals by shaping the TEM horn antenna to look like a Vivaldi antenna. The antenna structure is modified by a dielectric load in the center to increase the gain bandwidth. It is placed in a surrounding box made of PEC material to reduce the undesired side lobes and to obtain more directive radiation pattern. The simulations are performed by using the CST STUDIO SUITE electromagnetic (EM) simulation software and they are later verified by the actual measurements. The Vivaldi shaped partially dielectric loaded (VS-PDL) TEM horn antenna is proposed as a compact UWB antenna for systems using the newly established UWB band and also for the communication systems of popular bands like ISM, Wi-Fi, and GSM.

scholarly journals Array Synthesis Horn Antenna with an Extended Horn and a Stepped Corrugated Structure for High-Power Microwave Applications

2020 ◽  
Vol 20 (2) ◽  
pp. 110-114
Author(s):  
Yoon-Seon Choi ◽  
Ji-Hun Hong ◽  
Jong-Myung Woo
Keyword(s):  
High Power ◽  
Horn Antenna ◽  
High Gain ◽  
Horn Antennas ◽  
High Power Microwave ◽  
Microwave System ◽  
Pyramidal Horn ◽  
Microwave Applications ◽  
Corrugated Structure ◽  
Power Microwave

This study proposes an array synthesis horn antenna with an extended horn and a stepped corrugated structure for a high-power microwave system. The horn antenna is designed by joining four pyramidal horn antennas and an extended horn to obtain a high gain. To improve the beam pattern in the H-plane, the length of the vertical junction of the pyramidal horns is controlled. Two-stepped and partitioned corrugated structures are attached to both horizontal edges of the aperture for a good front-to-back ratio. The designed 2 × 2 array synthesis horn antenna has a gain of 19.7 dBi and front-to-back ratio of 39.6 dB in the measurement.

scholarly journals Design and analysis of quad ridged horn antenna for high gain application

2020 ◽  
Vol 1706 ◽  
pp. 012099
Author(s):  
Urvi Barapatre ◽  
Suman Panchal ◽  
Jagdish M Rathod ◽  
P H Panchal ◽  
Kush Parikh
Keyword(s):  
Horn Antenna ◽  
High Gain

scholarly journals The YadA Protein of Yersinia pseudotuberculosis Mediates High-Efficiency Uptake into Human Cells under Environmental Conditions in Which Invasin Is Repressed

2002 ◽  
Vol 70 (9) ◽  
pp. 4880-4891 ◽  
Author(s):  
Julia Eitel ◽  
Petra Dersch
Keyword(s):  
Extracellular Matrix ◽  
Mammalian Cells ◽  
Yersinia Pseudotuberculosis ◽  
High Efficiency ◽  
Environmental Parameters ◽  
Infection Process ◽  
Nutrient Concentrations ◽  
Integrin Receptors ◽  
Uptake Process ◽  
High Level

ABSTRACT The YadA protein is a major adhesin of Yersinia pseudotuberculosis that promotes tight adhesion to mammalian cells by binding to extracellular matrix proteins. In this study, we first addressed the possibility of competitive interference of YadA and the major invasive factor invasin and found that expression of YadA in the presence of invasin affected neither the export nor the function of invasin in the outer membrane. Furthermore, expression of YadA promoted both bacterial adhesion and high-efficiency invasion entirely independently of invasin. Antibodies against fibronectin and β1 integrins blocked invasion, indicating that invasion occurs via extracellular-matrix-dependent bridging between YadA and the host cell β1 integrin receptors. Inhibitor studies also demonstrated that tyrosine and Ser/Thr kinases, as well as phosphatidylinositol 3-kinase, are involved in the uptake process. Further expression studies revealed that yadA is regulated in response to several environmental parameters, including temperature, ion and nutrient concentrations, and the bacterial growth phase. In complex medium, YadA production was generally repressed but could be induced by addition of Mg2+. Maximal expression of yadA was obtained in exponential-phase cells grown in minimal medium at 37°C, conditions under which the invasin gene is repressed. These results suggest that YadA of Y. pseudotuberculosis constitutes another independent high-level uptake pathway that might complement other cell entry mechanisms (e.g., invasin) at certain sites or stages during the infection process.

scholarly journals H-plane horn antenna with enhanced directivity using conformal transformation optics

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hossein Eskandari ◽  
Juan Luis Albadalejo-Lijarcio ◽  
Oskar Zetterstrom ◽  
Tomáš Tyc ◽  
Oscar Quevedo-Teruel
Keyword(s):  
Conformal Transformation ◽  
Phase Error ◽  
Three Dimensional ◽  
Physical Space ◽  
Horn Antenna ◽  
High Gain ◽  
Transformation Optics ◽  
Graded Index ◽  
Low Profile ◽  
Dielectric Lens

AbstractConformal transformation optics is employed to enhance an H-plane horn’s directivity by designing a graded-index all-dielectric lens. The transformation is applied so that the phase error at the aperture is gradually eliminated inside the lens, leading to a low-profile high-gain lens antenna. The physical space shape is modified such that singular index values are avoided, and the optical path inside the lens is rescaled to eliminate superluminal regions. A prototype of the lens is fabricated using three-dimensional printing. The measurement results show that the realized gain of an H-plane horn antenna can be improved by 1.5–2.4 dB compared to a reference H-plane horn.

scholarly journals Selective Laser Melting Process of Al–Based Pyramidal Horns for the W-Band: Fabrication and Testing

2021 ◽  
Author(s):  
L. Lamagna ◽  
A. Paiella ◽  
S. Masi ◽  
L. Bottini ◽  
A. Boschetto ◽  
...  
Keyword(s):  
Selective Laser Melting ◽  
High Surface ◽  
Melting Process ◽  
Horn Antenna ◽  
Post Processing ◽  
Laser Melting ◽  
Performance Impact ◽  
Horn Antennas ◽  
Sand Blasting ◽  
W Band

AbstractIn the context of exploring the possibility of using Al-powder Selective Laser Melting to fabricate horn antennas for astronomical applications at millimeter wavelengths, we describe the design, the fabrication, the mechanical characterization, and the electromagnetic performance of additive manufactured horn antennas for the W-band. Our aim, in particular, is to evaluate the performance impact of two basic kinds of surface post-processing (manual grinding and sand-blasting) to deal with the well-known issue of high surface roughness in 3D printed devices. We performed comparative tests of co-polar and cross-polar angular response across the whole W-band, assuming a commercially available rectangular horn antenna as a reference. Based on gain and directivity measurements of the manufactured samples, we find decibel-level detectable deviations from the behavior of the reference horn antenna, and marginal evidence of performance degradation at the top edge of the W-band. We conclude that both kinds of post-processing allow achieving good performance for the W-band, but the higher reliability and uniformity of the sand-blasting post-process encourage exploring similar techniques for further development of aluminum devices at these frequencies.

scholarly journals High-Efficiency Polarizer Reflectarray Antennas for Data Transmission Links from a CubeSat

Electronics ◽  
2021 ◽  
Vol 10 (15) ◽  
pp. 1802
Author(s):  
Eduardo Martinez-de-Rioja ◽  
Daniel Martinez-de-Rioja ◽  
Rafael López-Sáez ◽  
Ignacio Linares ◽  
Jose A. Encinar
Keyword(s):  
Circular Polarization ◽  
Data Transmission ◽  
High Efficiency ◽  
High Gain ◽  
Dual Band ◽  
Left Handed ◽  
Linearly Polarized ◽  
Flat Profile ◽  
First Time ◽  
Collimated Beam

This paper presents two designs of high-efficiency polarizer reflectarray antennas able to generate a collimated beam in dual-circular polarization using a linearly polarized feed, with application to high-gain antennas for data transmission links from a Cubesat. First, an 18 cm × 18 cm polarizer reflectarray operating in the 17.2–22.7 GHz band has been designed, fabricated, and tested. The measurements of the prototype show an aperture efficiency of 52.7% for right-handed circular polarization (RHCP) and 57.3% for left-handed circular polarization (LHCP), both values higher than those previously reported in related works. Then, a dual-band polarizer reflectarray is presented for the first time, which operates in dual-CP in the frequency bands of 20 GHz and 30 GHz. The proposed antenna technology enables a reduction of the complexity and cost of the feed chain to operate in dual-CP, as a linear-to-circular polarizer is no longer required. This property, combined with the lightweight, flat profile and low fabrication cost of printed reflectarrays, makes the proposed antennas good candidates for Cubesat applications.

Sign in / Sign up

Export Citation Format

Share Document