ETS-Lindgren 6512 Shielded Loop Antenna - Manual (Page 33)

www.ets-lindgren.com Radiation Pattern 33
7.0 Radiation Pattern
The 6500 Series Loop Antennas are electrically small loops (size is small in
wavelengths), giving them identically-shaped radiation patterns. Each loop
operates at a frequency under 30 MHz. At 30 Hz the wavelength is 10 m; the
largest loops have a circumference of 1.88 m (C=πD), which is much smaller
than the wavelength.
For electrically small loops it can be assumed that the current on the loop is
constant. If we place the loop on the plane z=0 so that the z-axis is perpendicular
to the plane of the loop and following the derivation presented by Balanis in
Antenna Theory: Analysis and Design
(2nd Ed. John Wiley and Sons: New York
1997), it follows that the radiated magnetic fields are given by:
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[
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And the radiated electric fields are given by:
( )
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