scholarly journals A New Agile Radiating System Called Electromagnetic Band Gap Matrix Antenna

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Hussein Abou Taam ◽  
Moustapha Salah Toubet ◽  
Thierry Monediere ◽  
Bernard Jecko ◽  
Mohammad Rammal

Civil and military applications are increasingly in need for agile antenna devices which respond to wireless telecommunications, radars, and electronic warfare requirements. The objective of this paper is to design a new agile antenna system called electromagnetic band gap (EBG) matrix. The working principle of this antenna is based on the radiating aperture theory and constitutes the subject of an accepted CNRS patent. In order to highlight the interest and the originality of this antenna, we present a comparison between it and a classical patch array only for the (one-dimensional) 1D configuration by using a rigorous full wave simulation (CST Microwave software). In addition, EBG matrix antenna can be controlled by specific synthesis algorithms. These algorithms use inside their; optimization loop an analysis procedure to evaluate the radiation pattern. The analysis procedure is described and validated at the end of this paper.

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Shruti Vashist ◽  
M. K. Soni ◽  
P. K. Singhal

Rotman lenses are the beguiling devices used by the beamforming networks (BFNs). These lenses are generally used in the radar surveillance systems to see targets in multiple directions due to its multibeam capability without physically moving the antenna system. Now a days these lenses are being integrated into many radars and electronic warfare systems around the world. The antenna should be capable of producing multiple beams which can be steered without changing the orientation of the antenna. Microwave lenses are the one who support low-phase error, wideband, and wide-angle scanning. They are the true time delay (TTD) devices producing frequency independent beam steering. The emerging printed lenses in recent years have facilitated the advancement of designing high performance but low-profile, light-weight, and small-size and networks (BFNs). This paper will review and analyze various design concepts used over the years to improve the scanning capability of the lens developed by various researchers.


Author(s):  
Abdelmoumen Kaabal ◽  
Mustapha El Halaoui ◽  
Saida Ahyoud ◽  
Adel Asselman

In this chapter, a detailed study of the one-dimension electromagnetic band gap (1D-EBG) structures and their application in a directional antenna design are presented. To improve the ability and analyze and understand the behavior of 1D-EBG, three techniques of analysis are developed. The results show that the periodicity of the dielectric permittivity makes it possible to stop the waves propagation in certain frequency bands. A comparison between the different methods shows an excellent agreement. An evolution of the transmission coefficient of a structure consisting of six layers with a cavity of thickness equal a wavelength in the middle of the structure, shows that there is a peak of transmission which is formed at the center frequency of the band gap and reflects a resonance phenomenon. This phenomenon of frequency filtering is exploited for the design of a directive EBG antenna by introducing an excitation to the cavity center.


2019 ◽  
Vol 11 (10) ◽  
pp. 1035-1043 ◽  
Author(s):  
Mahmoud A. Abdalla ◽  
Abdullah A. Al-Mohamadi ◽  
Ibrahim S. Mohamed

AbstractA high selective dual band and miniaturized electromagnetic band gap (EBG) unit cell is presented in this paper. The analysis and characterization of the new cell are explained. The modified compact EBG unit cell is based on cutting two inverted U-shaped slots inside the typical mushroom-like EBG. The modified EBG has a 70% size reduction. The dual-band functionality of the structure is confirmed by applying it in a dual-notch ultra-wideband antenna (3.1–10.6 GHz), and the notch frequencies are 5.2 and 5.8 GHz. The dual-band functionality has advantages of a highly selective bandpass between them. The antenna can suppress interference frequencies in less than 100 MHz bandwidth without affecting the antenna performance in the whole bandwidth. Presented results are addressed in terms of circuit modeling, 3D full-wave simulations, and measurements.


Electronics ◽  
2021 ◽  
Vol 10 (18) ◽  
pp. 2263
Author(s):  
Enrique A. Navarro ◽  
Jorge A. Portí ◽  
Alfonso Salinas ◽  
Enrique Navarro-Modesto ◽  
Sergio Toledo-Redondo ◽  
...  

The word radome is a contraction of radar and dome. The function of radomes is to protect antennas from atmospheric agents. Radomes are closed structures that protect the antennas from environmental factors such as wind, rain, ice, sand, and ultraviolet rays, among others. The radomes are passive structures that introduce return losses, and whose proper design would relax the requirement of complex front-end elements such as amplifiers. The radome consists mostly in a thin dielectric curved shape cover and sometimes needs to be tuned using metal inserts to cancel the capacitive performance of the dielectric. Radomes are in the near field region of the antennas and a full wave analysis of the antenna with the radome is the best approach to analyze its performance. A major numerical problem is the full wave modeling of a large radome-antenna-array system, as optimization of the radome parameters minimize return losses. In the present work, the finite difference time domain (FDTD) combined with a genetic algorithm is used to find the optimal radome for a large radome-antenna-array system. FDTD uses general curvilinear coordinates and sub-cell features as a thin dielectric slab approach and a thin wire approach. Both approximations are generally required if a problem of practical electrical size is to be solved using a manageable number of cells and time steps in FDTD inside a repetitive optimization loop. These approaches are used in the full wave analysis of a large array of crossed dipoles covered with a thin and cylindrical dielectric radome. The radome dielectric has a thickness of ~λ/10 at its central operating frequency. To reduce return loss a thin helical wire is introduced in the radome, whose diameter is ~0.0017λ and the spacing between each turn is ~0.3λ. The genetic algorithm was implemented to find the best parameters to minimize return losses. The inclusion of a helical wire reduces return losses by ~10 dB, however some minor changes of radiation pattern could distort the performance of the whole radome-array-antenna system. A further analysis shows that desired specifications of the system are preserved.


2014 ◽  
Author(s):  
Amir I. Zaghloul ◽  
Youn M. Lee ◽  
Gregory A. Mitchell ◽  
Theodore K. Anthony

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