Design of Linear antenna array using Dolph-Chebyshev method

This paper illustrates a design of linear array antenna equal space and non uniform excitation using Dolph – Chebyshev method , We will discuss the designing procedure for antenna array having odd or even number of elements at two different values of the major to minor sidelobe level and at various between spaces , we will calculate the excitation coefficients and plot the radiation pattern for each case in addition to calculate both of the half power beam width angel and directivity. Finally : two curves will be plotted : first of them for beam broadening factor as a function of the major to minor sidelobe ratio ,the other one for directivity as a function of the array length.

Design and characterization of parabolic acoustic dish

Usually, a reflector dish with a loudspeaker or a microphone placed at its focal point is used in directed acoustic systems to determine the direction in which the acoustic wave is transmitted or received, in addition to improve the gain in the acoustic transmission or reception. As the parabolic reflector dish with an oval aperture has significant advantages, and there is no relationship between parameters of this dish and some variables that have direct influence on acoustical emission or reception of this dish, this work is intended to find this relationship, and this is achieved by carrying out a theoretical and experimental study to find the optimum utilization of this dish in directed acoustic systems.

Study and characterization of acoustic gain of parabolic reflector

The parabolic reflector is used in directed acoustic systems, with the aim of gettingdirectivity, as well as increasing the gain in transmission and reception. Therefore, a theoretical study was carried out to describe the factors that affect the gain of the parabolic dish in the acoustic field. The frequency-gain relationship was experimentally obtained using a parabolic dish with an elliptical aperture, in addition to the analysis of the factors that led to the deviation of the experimental relationship from the theoretical relationship.

Evaluate the performance of a wide band LPDA antenna and compare it with a half-wavelength antenna at frequency change

Antennas have become an indispensable basic need, especially in the area of wireless networks, and have developed in the past few decades in a very large way in terms of profit and resistance, bandwidth, bandwidth, radiation pattern, etc. in line with new and increasing requirements. In this study, we are interested in studying a broad band antenna where this antenna is very important in systems that operate on a set of frequencies rather than at a fixed frequency. The traditional antennas that are designed at a specific frequency change their response significantly if used on a wide bandwidth around the designed frequency In this study, the LPDA (Log periodic dipole Array) antenna was designed and studied in a broadband field and compared to the antenna reference of wire antennas. It is a halfwavelength antenna λ/2. The study of the effect of frequency change in the antenna radiation pattern and the radiation beam Half-power level and front-to-back ratio (F/B).