Log-Periodic Antenna


Also found in: Wikipedia.

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 ?
Furthermore, note that the extracted poles of the use of the commercial off-the-shelf log-periodic antenna whose bandwidth was not ultra-wideband were almost identical to those of the bow-tie and Vivaldi antennas which were designed for the particular purpose when performing the STMPM with filtering the antenna effects.
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.
While referring to broad-band antenna, from low frequency to ultra-high frequency, there are common antennas used for compromising emanation eavesdropping, e.g., active monopole antenna works in the bandwidth at 100 Hz ~ 30 MHz; bi-conical antenna at 30 MHz ~ 300 MHz; log-periodic antenna at 200 MHz ~ 1000 MHz, and discone antenna at 200 MHz ~ 1300 MHz.
The lower frequency band uses a biconical antenna while the higher frequency band uses a log-periodic antenna (although the range from 30 to 1000 MHz can also be handled with a single broadband antenna).
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.
The measurements were performed with a generator, broadband amplifier, log-periodic antenna and electric field meter, as shown in Figure 8.
Chang, "Application of quasi log-periodic antenna for UHF passive RFID tag design featuring constant power transmission coefficient over broadband operation," Journal of Electromagnetic Waves and Applications, Vol.
And it determines the polarization direction of the log-periodic antenna composed of the treelike fractal dipole is also in y direction.
The log-periodic part of the AC-220 is 37" long x 22" wide, approximately the same size as the company's Model AL-100, a log-periodic antenna covering 300 MHz to 1 GHz.
The harmonic mixer consists of a back-to-back Schottky-barrier diode chip placed at the apex of a wideband log-periodic antenna, as shown in Figure 2.
The FCC recommends a log-periodic antenna below 960 MHz although other types of measurement antennas such as biconicals may be used.