Loop Antenna ShapeJanuary 9th Fact-of-the-Day
It often is said that loop antennas should enclose the greatest possible area and that because with a given wire length a circle encloses more area than any other shape, a circular shape is optimum. That is true for loops with circumferences that are small compared to a wavelength, but generally is not true for large loops. The shape of a loop that has a circumference significantly greater than a wavelength has a big effect on its directional pattern. It also affects other important characteristics. It is possible that a circular shape will happen to be optimum for a particular large-loop application, but the odds are high that it won't be. Antenna modeling programs such as MMANA make it easily to experimentally investigate the characteristics of various loop shapes. ©2005 Martek International All rights reserved.
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