{"id":1215,"date":"2022-10-11T22:48:33","date_gmt":"2022-10-11T22:48:33","guid":{"rendered":"https:\/\/antennasimulator.com\/?post_type=epkb_post_type_1&p=1215"},"modified":"2026-02-20T04:24:12","modified_gmt":"2026-02-20T04:24:12","slug":"archimedean-spiral","status":"publish","type":"epkb_post_type_1","link":"https:\/\/antennasimulator.com\/index.php\/knowledge-base\/archimedean-spiral\/","title":{"rendered":"Archimedean Spiral"},"content":{"rendered":"\n

An Archimedean Spiral<\/strong> represents an Archimedes\u2019 spiral in AN-SOF.<\/p>\n\n\n\n

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The Archimedean spiral is a planar spiral defined by the polar equation:<\/p>\n\n\n\n

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$\\displaystyle r(\\alpha) \\,=\\, r_0 \\,+\\, \\frac{p}{2\\pi} \\; \\alpha$<\/p>\n\n\n\n

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where $r_0$ is the starting radius<\/strong>, $p$ is the pitch<\/strong>, and $\\alpha$ is the angle in the plane of the spiral, ranging from $0$ to $2\\pi M$, with $M$ representing the number of turns<\/strong>.<\/p>\n\n\n\n

The spiral’s starting radius is $r(0) = r_0$ and its ending radius is $r(2\\pi M) = r_0 + pM$. Consequently, the pitch $p$ represents the constant spacing between consecutive turns. Additionally, the pitch is equal to the constant growth rate of the spiral radius $r(\\alpha)$ per turn, expressed as:<\/p>\n\n\n\n

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$\\displaystyle p \\,=\\, 2\\pi \\frac{dr}{d\\alpha}$<\/p>\n\n\n\n

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Accessing the Archimedean Spiral Dialog Box<\/h3>\n\n\n\n
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To open the Archimedean Spiral<\/strong> dialog box:<\/p>\n\n\n\n

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  1. Navigate to Draw > Archimedean Spiral<\/strong> in the main menu.<\/li>\n\n\n\n
  2. The dialog box contains three tabs: Archimedean Spiral<\/strong>, Attributes<\/strong>, and Materials<\/strong> (Fig. 1<\/strong>).<\/li>\n<\/ol>\n\n\n\n
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    Archimedean Spiral Tab: Setting Geometrical Parameters<\/h3>\n\n\n\n
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    Define the Archimedean spiral by specifying the following (Fig. 1<\/strong>):<\/p>\n\n\n\n