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Technologies
Published in Henry H. Perritt, Eliot O. Sprague, Domesticating Drones, 2016
Henry H. Perritt, Eliot O. Sprague
Many different types of directional antennas exist. Yagis are a paradigm. They comprise several antenna elements (the elements are the bars that stick out from the boom) in a row. Only one of these elements (the driven element) receives an electrical signal from the transmitter or feeds a received signal to the receiver. The others either passively reflect or concentrate the signal from the driven element. The antenna elements get progressively smaller from back to front. The longer elements behind the driven element reflect the signal, while the smaller elements in front of the driven element concentrate (direct) it.
Optimal Design of Linear Antenna Arrays of Dipole Elements Using Flower Pollination Algorithm
Published in IETE Journal of Research, 2019
Gopi Ram, Rajib Kar, Durbadal Mandal, Sakti Prasad Ghoshal
The dipole antenna is one of the utmost influential and generally used radio frequency (RF) antennas. Dipole antenna is generally used independently and also can be incorporated in many other RF antenna designs where it forms the driven element for the antenna. Dipole antenna is constructed with two thin dipole elements that are symmetrically fed at the centre by a balanced two-wire transmission line [1]. Dipole antennas are of various types like Hartzian dipole, half-wave dipole, small dipole [2] etc. To match with the line impedance, the radiation resistance of the dipole antenna should be of 73 ohms. In this paper, linear array of dipole element is considered. The radiation properties of the antenna arrays can be modified by their geometrical configurations or by the variable parameters of the array factors [1–9].
A Planar Printed Four-Element Pattern Diversity MIMO Antenna Based on Novel Quasi-Yagi Elements
Published in IETE Journal of Research, 2021
The simulated vector current distributions of the single QYA element at three different frequencies (1.6, 2.3, and 3 GHz) is shown in Figure 6. The directional surface current vectors on the driven element are observed with opposite surface currents on the reflector and/or director at all frequencies, resulting in an end-fire radiation pattern. Also, it is observed from the surface current that the driven elements operate over a larger BW. It helps to maintain the directional radiation characteristic over the entire BW.