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.

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.

References in periodicals archive ?
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.
The University wishes to appoint a design company to develop the mechanical design of a log-periodic antenna sub-system covering 50-650MHz for the low frequency aperture array element of the Square Kilometre Array, SKA, radio telescope.
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.
In this paper, we propose a coplanar waveguide (CPW)-fed log-periodic slot antenna with a special cavity for transforming the bidirectional beam into a unidirectional beam at the desired frequency band.
However, most of these kinds of antennas are limited by their large volume for certain applications; d) frequency independent antennas, including equiangular and Archimedean spirals, log-periodic dipole antennas, and so on.
The author employs mathematical tools--specifically, log-periodic power laws--to study the prebubble or precrash buildup in a financial system to its critical point.
Prasad, "Wideband, Planar, Log-periodic Balun," IEEE IMS Digest, 1998, pp.
The company also will highlight its latest antenna offering--the AT700M12G wideband trapezoidal log-periodic antenna (Figure 2), which operates from 700 MHz to 11 GHz.