Wide Band Antenna with Ultra-smooth Spectral Characteristics

2021 ◽  
Vol 35 (11) ◽  
pp. 1292-1293
Author(s):  
Agaram Raghunathan ◽  
B. Girish ◽  
R. Somashekar ◽  
K. Srivani ◽  
Saurabh Singh ◽  
...  
Keyword(s):  
Spectral Characteristics ◽  
Wide Band ◽  
Antenna Design ◽  
Observational Cosmology ◽  
Spectral Signature ◽  
Spectral Features ◽  
Surface Currents ◽  
Frequency Range ◽  
Measurement Results ◽  
Frequency Independent

Understanding the evolution of Universe is, in the forefront of, the modern day observational cosmology. It requires precise and accurate measurement of cosmological signal, orders of magnitude weaker than the bright sky background. Detection of such a signal having distinct spectral signature, needs an antenna with frequency independent characteristics over more than an octave bandwidth. A spherical monopole antenna has been designed to operate in the frequency range 50-200 MHz with a spectral smoothness of about few parts in 104. The structure has been modeled and optimized using WIPL-D, to minimize spectral features arising out of abrupt reflections of surface currents and frequency dependent radiation patterns. A prototype has been built to validate the design. This paper presents the methodology adopted in the overall antenna design, experiences in its prototyping and simulation and the measurement results.

A flexible wide band single fed slot antenna with circular polarizing rotated elliptical ground and impulse response

2019 ◽  
Vol 11 (9) ◽  
pp. 872-884 ◽  
Author(s):  
Sherif R. Zahran ◽  
Mahmoud A. Abdalla ◽  
Abdelhamid Gaafar
Keyword(s):  
Liquid Crystalline ◽  
Axial Ratio ◽  
Wide Band ◽  
Crystalline Polymer ◽  
Antenna Design ◽  
Slot Antenna ◽  
Efficient Design ◽  
Measurement Results ◽  
Highly Correlated ◽  
Good Agreement

AbstractIn this paper, a flexible single fed planar circular polarized slot antenna is proposed for Internet of Things wideband applications. The antenna flexibility is achieved by employing a mechanically bendable liquid crystalline polymer substrate. The overall antenna volume is 50 mm × 42 mm × 0.1 mm. The antenna design uses 45° rotated elliptical ground structure for generating circular polarized radiation over wideband spectrum. Two parametrical analyses targeting the slot ground are introduced in order to achieve the most efficient design. The final antenna design demonstrates a good matching in terms of reflection coefficient (<−10 dB), semi-omnidirectional radiation patterns, average gain of 4 dB, and <3 dB axial ratio over entire frequency band of operation. All antenna parameters are studied in both straight and bent antenna setup scenarios. Good agreement between simulation and measurement results of the antenna parameters are achieved. For both straight and bent antenna scenarios, the antenna receiving functionality in time domain is confirmed by retrieving highly correlated impulse responses.

scholarly journals Wide Band Parasitic Microstrip Antenna using Multiple Feedline for Mobile Communication

2019 ◽  
Vol 9 (1) ◽  
pp. 1887-1891
Keyword(s):  
Mobile Communication ◽  
Communication System ◽  
Microstrip Antenna ◽  
Return Loss ◽  
Wide Band ◽  
Frequency Range ◽  
Optimal Bandwidth ◽  
Feed Line ◽  
Measurement Results ◽  
Working Frequency

his paper proposes design of parasitic microstrip antenna with multiple feed line for mobile communication applications at range frequency of 1800 – 2100 MHz. The purpose of adding multiple feed line is to enhanced the bandwidth of the proposed antenna. The multiple feed line used has an impedance of 100 Ohm and is placed on the edge of the patch parasitic microstrip antenna. The optimal bandwidth of the microstrip antenna is obtained by adjusting the dimensions and position of the multiple feed line. From the measurement results obtained return loss of -14.91 dB, VSWR of 1.44 at working frequency of 1800 MHz and bandwidth of 427 MHz with a frequency range 1715 MHz - 2142 MHz. . From these results it can be concluded that the banwidth of proposed antenna has met the criteria to be used in a mobile communication system.

Modelling and optimization of the linear tapered slot antenna

2021 ◽  
Author(s):  
Yu.S. Blinova ◽  
V.E. Drach ◽  
A.A. Litvinenko ◽  
A.V. Rodionov
Keyword(s):  
Microstrip Antenna ◽  
Wide Band ◽  
Antenna Design ◽  
Slot Antenna ◽  
Main Lobe ◽  
Frequency Range ◽  
Radar Sensor ◽  
Multiple Parameters ◽  
Ground Plate ◽  
Modelling And Optimization

A key component of any phased array or radar sensor is its antenna. For ultra wide band systems usually four types of antenna are being used: microstrip, tapered slot, sinuous and Yagi-Uda. The microstrip antenna generates two main lobes, which makes it a bidirectional antenna, like the tapered slot, sinuous, or Yagi-Uda antennae. Several efforts had been made to shift the bidirectional character of the microstrip antenna into unidirectional by placing a ground plate to absorb the undesirable main lobe. These efforts successfully eliminated the undesirable main lobe; however, side effects were introduced along the way, such as the remaining main lobe’s direction became frequency dependent. On the other hand, the sinuous antenna design is very complex when compared with the tapered slot antenna, involving multiple curvatures and angles. The Yagi–Uda antenna design, although less complex than the sinuous, still requires multiple segments and is more complicated than the tapered slot antenna. This study examined and analyzed primary parameters regarding their individual impact on linear tapered slot antenna design. The result is a set of recommendations for linear tapered slot antenna design to operate within the UWB frequency range. Unlike previous studies, which only focused on a certain set of these parameters, this paper provides a comprehensive recommendation for the parameters, which should result in a functional tapered slot antenna design. This set of recommendation can also serve as a base for further optimization, if desired. When used for optimization, the results from this study can guide the direction of changes when multiple parameters need to be adjusted simultaneously. Furthermore, this set of recommendations can be applied to other tapered slot antenna designs, as they all share, although are not defined completely, by these investigated parameters.

scholarly journals Investigation on Symmetric and Asymmetric Broadband Low-Loss W-Band Pillbox Windows

Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2060
Author(s):  
Tongbin Yang ◽  
Xiaotong Guan ◽  
Wenjie Fu ◽  
Dun Lu ◽  
Chaoyang Zhang ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Wide Band ◽  
Simulation Software ◽  
Experimental Results ◽  
Frequency Range ◽  
Low Loss ◽  
W Band ◽  
Measurement Results ◽  
Vacuum Electronic Devices ◽  
Wave Region

In order to develop wide-band low-loss windows for W-band vacuum electronic devices and easily fabricate them, symmetric and asymmetric pillbox windows are investigated and reported in this paper. A symmetric pillbox window and an asymmetric pillow-box window were designed, simulation optimized, fabricated, and tested. The initial parameters for the two pillbox windows were designed by equivalent circuit theory. Computer simulation technology (CST) three-dimensional (3D) electromagnetic simulation software was used to verify and optimize the design. Because of the uncontrollability of welding during the experiment, this article provides two solutions. One is to measure and reprocess the symmetrical pillbox window with the dielectric sheet welded to reduce the influence of welding on the measurement results; the other is an asymmetrical box window which is designed to avoid the error caused by the welding of the box window. The best experimental results for the symmetric pillbox window were |S21| close to 1 dB and reflection parameter |S11| close to 10 dB in the frequency range of 77–110 GHz. The experimental results for the asymmetric pillbox window were |S21| < 1 dB nearly in the frequency range of 76–109.5 GHz. The experimental results show that both solutions efficiently complete the design of broadband pillbox windows and would potentially be operated in the gigahertz millimeter-wave region.

A wide‐band electromagnetic exploration method—Some theoretical and experimental results

Geophysics ◽  
1980 ◽  
Vol 45 (5) ◽  
pp. 928-940 ◽  
Author(s):  
I. J. Won
Keyword(s):  
Circular Cylinder ◽  
Laboratory Experiments ◽  
Spectral Characteristics ◽  
Wide Band ◽  
Spectral Profile ◽  
Frequency Range ◽  
Sweep Frequency ◽  
Frequency Source ◽  
Intuitive Interpretation ◽  
Frequency Distance

Theoretical electromagnetic (EM) responses of a conductive circular cylinder in a conductive half‐space are obtained for a frequency range between 10 Hz and 30 kHz. The results show that the spectral characteristics can be used to determine the subsurface configuration of a target body, particularly in terms of its depth. Laboratory experiments using a wide‐band sweep‐frequency source provide support for the theoretical prediction of the spectral behavior. The experiment employed a harmonic EM source continuously sweeping logarithmically from 4 kHz to 4 MHz over a graphite slab submerged in a conductive solution. The results suggest that a wide‐band EM spectral profile displayed in a frequency‐distance space may provide many intuitive interpretation schemes which may not be possible with a single or discrete frequency profile.

Microwave wide band absorption by carbon from Corn cob-1

2016 ◽  
Vol 12 (2) ◽  
pp. 4204-4212 ◽  
Author(s):  
Maheshwar Sharon ◽  
Ritesh Vishwakarma ◽  
Abhijeet Rajendra Phatak ◽  
Golap Kalita ◽  
Nallin Sharma ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
Agricultural Waste ◽  
Wide Band ◽  
Nickel Nitrate ◽  
Equivalent Amount ◽  
Frequency Range ◽  
Corn Cob ◽  
Different Temperatures ◽  
Band Absorption ◽  
5 Ghz

Corn cob, an agricultural waste, is paralyzed at different temperatures (700oC, 800oC and 900oC). Microwave absorption of carbon in the frequency range of 2 GHz to 8 GHz is reported. Carbon activated  with 5%  nickel nitrate showed more than 90% absorption of microwave in the frequency range from 6 GHz to 8 GHz, while carbon activated  with 10% Nickel nitrate treated corn cob showed 90% absorption  in the frequency range of 2.5 GHz to 5 GHz. Carbon showing the best absorption are characterized by XRD, Raman spectra and SEM . It is suggested that corn cob treatment   alone with KOH did not improve the microwave absorption, whereas treatment along with nickel nitrate improved the absorption property much better. It is proposed that treatment with nickel nitrate helps in creating suitable pores in carbon   which improved the absorption behavior because while treating carbon with 1N HCl helps to leach out nickel creating equivalent amount of pores in the carbon.

New aspects of power grid facilities personnel workplaces electromagnetic environment

2020 ◽  
Vol 60 (9) ◽  
pp. 569-574
Author(s):  
Nina B. Rubtsova ◽  
Sergey Yu. Perov ◽  
Olga V. Belaya ◽  
Tatiana A. Konshina
Keyword(s):  
Transmission Lines ◽  
Power Transmission ◽  
Power Grid ◽  
Spectral Characteristics ◽  
Ground Level ◽  
Frequency Characteristics ◽  
Frequency Range ◽  
Electromagnetic Environment ◽  
Limit Values ◽  
Special Assessment

Introduction. Electromagnetic safety of power grid facilities staff requires the exclusion of electromagnetic fields (EMF) harmful effects. EMF is evaluated by 50 Hz electric and magnetic fields (EF and MF) values in the framework of working conditions special assessment, and very rarely the analysis of the electromagnetic environment (EME) is carried out in depth. The aim of the study - EME hygienic assessment of power grid EHV facilities personnel workplace with adequate 50 Hz EF and MF levels evaluation as well as the analysis of EF and MF in the frequency range from 5 Hz to 500 Hz amplitude-frequency characteristics. Materials and methods. 50 Hz EF and MF values assessment was carried out on open switchgears (S) of substations and within sanitary breaks of 500 and 750 kV overhead power transmission lines (OTL). Measurements along to OTL trasses was performed using matrix-based method. Measurements and analysis of EF and MF values in 5-500 Hz frequency range amplitude-frequency characteristics were performed in the territory of 500 and 750 kV S. Results. Power frequency 50 Hz measurements results at 500 and 750 kV S ground-level personnel workplaces showed the presence of an excess of permissible limit values by EF intensity and the absence of an excess by MF. The measured EF values within 500 and 750 kV OTL sanitary gaps require limiting the working time of linemen due to the excess of the hygienic norms for full work shift, while the MP levels were almost completely within the standard values for persons not occupationally connected with electrical installations maintenance. MF and EE frequency range from 50 Hz to 500 Hz spectral characteristics analysis showed that 3rd harmonic percentage does not exceed 2.5% for EF and 6% for MF of the main level, the level of the 5th harmonic does not exceed 1% for EF and 3.5% for MF, the level of the 7th harmonic does not exceed 0.2% for EF and 0.8% for MF. These data show despite its low levels the contribution of MF different harmonics in a possible adverse impact on humane than EF corresponding harmonics. Conclusions. There was the confirmation of the previously justified use of the "matrix" scheme for of EF and MF values measurement along OTL routes. The relevance of to EF and MF all frequency components expos ure assessing possible health risk in extremely high voltage S territories and under OTL, based on international recommendations due to the lack of sanitary regulations in the Russian Federation for >50 Hz-30 kHz EF and MF, is shown.

scholarly journals Band notched self complementaryultra wideband antenna for wireless applications

2018 ◽  
Vol 7 (2.8) ◽  
pp. 529 ◽  
Author(s):  
Ch Ramakrishna ◽  
G A.E.Satish Kumar ◽  
P Chandra Sekhar Reddy
Keyword(s):  
High Frequency ◽  
Return Loss ◽  
Wide Band ◽  
Ultra Wideband ◽  
Impedance Bandwidth ◽  
Relative Dielectric Permittivity ◽  
Frequency Range ◽  
Ground Structure ◽  
Wireless Applications ◽  
Patch Edge

This paper presents a band notched WLAN self complementaryultra wide band antenna for wireless applications. The proposed antenna encounters a return loss (RL) less than -10dB for entire ultra wideband frequency range except band notched frequency. This paper proposes a hexagon shape patch, edge feeding, self complementary technique and defective ground structure. The antenna has an overall dimensionof 28.3mm × 40mm × 2mm, builton  substrate FR4 with a relative dielectric permittivity 4.4. And framework is simulated finite element method with help of high frequency structured simulator HFSSv17.2.the proposed antenna achieves a impedance bandwidth of 8.6GHz,  band rejected WLAN frequency range 5.6-6.5 GHz with  vswr is less than 2.

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