Log-Periodic Antenna

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log-periodic antenna

[′läg ‚pir·ē¦ad·ik an′ten·ə]
(electromagnetism)
A broad-band antenna which consists of a sheet of metal with two wedge-shaped cutouts, each with teeth cut into its radii along circular arcs; characteristics are repeated at a number of frequencies that are equally spaced on a logarithmic scale.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Log-Periodic Antenna

 

a type of a frequency-independent antenna with periodic repetition of the ratios of the characteristic dimensions of the adjoining components. The repetition obeys a logarithmic law in such a way that the ratio between the wavelength of the electromagnetic oscillations being radiated and the characteristic dimensions of the excited part of the antenna remains virtually constant over a wide frequency range.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
This compact antenna, only 18.5" long and 8.5" high (47 cm x 22 cm), features a log-periodic design with 9 elements.
However, in our experiment, log-periodic, bow-tie, and Vivaldi antennas were selected based on the availability at the time of research and their dimensions in cm were 28.5 x 23, 17 x 27 x 13.5, and 55 x 70, respectively.
The company also highlighted its latest antenna offering-- the AT700M12G wideband trapezoidal log-periodic antenna (Figure 1), which operates from 700 MHz to 11 GHz.
It describes the theory of thin antennas, the integral equation method, folded antennas of metal wires, multi-folded and multi-level antennas, antennas with concentrated loads, the synthesis of directional radiators, the methods of a complex potential for cylindrical problems and three-dimensional problems, the principle of complementarities, problems of compensation and adjustment, arrays, transparent antennas, ship antennas, log-periodic antennas, and other issues, such as antennas for underground radio communication and observation and magnetic impedance antennas.
They also argued that most financial crashes are the climax of the so-called log-periodic power law signatures (LPPLS) associated with speculative bubbles [1].
Several topologies have been explored to achieve this, such as fractal geometry [17-19], multiple segments arrangement [20-22], log-periodic antennas [23-25] and nanocrescent antenna [26].
Fractals and log-periodic corrections applied to masses and energy levels of several nuclei.
The former finance professor adds a novel mathematical argument to his arsenal of warnings, this one based on a log-periodic pattern he calls "almost creepy" in the consistency with which successive market troughs come closer and closer in time to the ultimate blowoffs.
To meet the requirements of the modern communication standards, there has been increasing research on log-periodic microstrip antennas, which can simplify the systems, and reduce production costs.
Log-periodic dipole arrays (LPDA) of cylindrical wire dipoles are well known since the 50's, and their design rules are mainly based on the works of Isbel and Carrel [1-3].
This RF energy is harvested using a commercial log-periodic antenna and it is next converted to a DC voltage, using a voltage multiplier and a voltage regulator.