China
Africa
Explore chapters and articles related to this topic
Aperture and Phased Array Antennas
Published in Habibur Rahman, Fundamental Principles of Radar, 2019
The array antenna made up of individual radiating elements has a radiation pattern that is determined by the type of the individual elements used, their configurations, relative amplitude, and phases of the currents feeding them. For simplicity of discussion we begin by considering elements forming the array to be identical isotropic point sources. The resulting radiation patterns are called the array factor. The principle of pattern multiplication will then be applied for the purpose of including the effects of actual elements used in the array. In an array of identical elements, the following are the controls that can be used to shape the overall radiation pattern of the antenna: the geometrical configurations,the relative spacing between consecutive elements,the amplitude excitation of the individual elements,the phase excitation of the individual elements, andthe relative radiation pattern of the individual elements.
A
Published in Philip A. Laplante, Comprehensive Dictionary of Electrical Engineering, 2018
array several antennas arranged together in space and interconnected to produce a desired radiation pattern. array factor in antenna theory, the resulting radiation pattern of an array when each antenna in the array is replaced by an isotropic radiator. array processor an array of processor elements operating in lockstep in response to a single instruction and performing computations on data that are distributed across the processor elements. array signal processing signal processing techniques used for extracting information based on signals from several (identical) sensors, for example an antenna array consisting of several antenna elements. arrester discharge current arrester during a surge. arrester discharge voltage arrester during a surge. ART network network. the current in an
Basic Array Theory and Pattern Synthesis Techniques
Published in Lal Chand Godara, Handbook of Antennas in Wireless Communications, 2018
With the array response defined in Eq. (16.1), an array factor is the special case of array response H when g is equal to [1 1 … 1]T. This means that when the antenna elements are all isotropic, the antenna array response is the array factor. It is also clear from Eqs. (16.1), (16.3) and (16.5) that if all gi’s are identical, an array response is the product of the array factor and the element factor (or element pattern, i.e., gi(f, θ, ϕ)). This is the so-called rule of pattern multiplication.
Performance Analysis of Dolph-Tschebyscheff Array for Different SLL and Array Length
Published in IETE Technical Review, 2023
Maloth Gopal, S. S. Patil, K. P. Ray
Antennas with high directional characteristics are essential in diverse applications to cater to the requirements of long-distance wireless communication. An array antenna, which is a collection of radiating elements organized in a linear/planar geometrical configuration, is used to achieve this. The relative displacement between the elements, the excitation amplitude and phase of the individual elements, and their relative radiation pattern determines the overall radiation pattern of an array antenna [1]. The total field of an array is calculated by multiplying the field of a single element by an array factor. The array factor is determined by the number of elements, the inter-element distance and phase, as well as the element excitation amplitudes. Dipoles, loops, slots, microstrips, horns, reflectors, and other elements are employed in a variety of antenna arrays used for personal, commercial, and military applications. Generally, array elements are considered identical to reduce the complexity.
Codebooks design and performance evaluation based on antenna array response and signal to noise ratio for mmWave communication
Published in Journal of International Council on Electrical Engineering, 2018
Adam Mohamed Ahmed Abdo, Xiongwen Zhao, Abdinasir Ahmed
Similarly, we can obtain array factor and codebook weight vector from corresponding array factor and codebook in a given direction. We assume that the antenna elements are located in plane, the polar angle with respect to is , the azimuth angle with respect to is , and are the spacing between elements in both direction, and are the number of antenna elements in the direction of and respectively, the AF is the result of AF in direction multiplied by AF in direction to give array factor as follow: , by using the summation consecutively of two AF to obtain the array factor as follow[11]:
Multi-Source Detection Performance of Some Linear Sparse Arrays
Published in IETE Journal of Research, 2022
P. Raiguru, D. C. Panda, R. K. Mishra
The radiation pattern of an array is the product of the element pattern and array factor. The array factor calculation uses isotropic sources. Therefore, the array factor of a sparse array must match that of the corresponding reference ULA. So, the platform for performance comparison of ULA and NLA is their array factors obtained from isotropic elements instead of physical elements. Hence, the term element shall mean isotropic element hereafter.