Calculator - Full-Wave Wire Loop
Use At Your Own Risk
Maple Leaf Communications assumes no responsibility for material calculation errors or other deficiencies in the calculator offered here.
Installed antennas can be affected by buildings, trees, mast properties, other antennas, ground conditions, and more.
Dimensions reported by this calculator should be considered only approximations of the length(s) of material required.
When ordering materials and building your antenna, allow a little extra length and trim as necessary instead of building and installing the antenna before discovering that it is too short.
Full-Wave Horizontal Wire Loop
A full-wave loop can require a lot of territory, and needs at least several tall supporting structures (trees, towers, etc.) However on the right property, it is an effective, low-noise, omnidirectional antenna.
The loop provides about 2dB of gain when hung in a square shape, but more if the shape of the antenna can be expanded to maximize interior space. Though impractical to hang, a true circle shape would provide nearly 1dB of gain over a square shape.
Theoretical impedance of the loop is 100 ohms, so it should be fed with a matching system designed to lower impedance closer to the 50 ohms of typical coaxial feedlines. One method involves a matching section of 75-ohm coax, carefully-cut so that it matches the dimension provided below after connections have been made. The dimension is calculated using the velocity factor of the 75-ohm coax used.
Enter the frequency of interest below. The dividend factor typically used for calculating full-wave loops is 1005, but it can be adjusted below if desired. The velocity factor input should be correct if the 75-ohm matching stub results will be used.