{"id":1407,"date":"2012-01-26T11:12:32","date_gmt":"2012-01-26T11:12:32","guid":{"rendered":"http:\/\/www.raymaps.com\/?p=1407"},"modified":"2012-02-01T13:28:27","modified_gmt":"2012-02-01T13:28:27","slug":"dipole-antenna","status":"publish","type":"post","link":"https:\/\/www.raymaps.com\/index.php\/dipole-antenna\/","title":{"rendered":"Half Wave Dipole Antenna"},"content":{"rendered":"

A dipole antenna is a simple antenna that can be built out of electrical wire. The most common dipole antenna is a half wave dipole which is constructed from a piece of wire half wavelength long. The wire is split in the center to connect the feeding wires. The E-field of the antenna has a circular pattern along a plane which cuts the axis of the antenna perpendicularly and is similar to a figure of 8 in a plane along the axis of the antenna [3D pattern<\/a>]. The exact E-field can be calculated as:<\/p>\n

\"Expression<\/a>
Expression for E-field of a Dipole Antenna<\/figcaption><\/figure>\n
\"E-field<\/a>
E-field Pattern of a Dipole Antenna<\/figcaption><\/figure>\n

The MATLAB code for generating the above pattern is given below.<\/p>\n

n=377;\r\nIo=1;\r\nr=10;\r\nlambda=0.3;\r\nk=(2*pi)\/lambda;\r\nL=lambda\/2;\r\n\r\ntheta=0:0.01:2*pi;\r\nE=j*n*Io*exp(-j*k*r)*(1\/(2*pi*r))*((cos(k*L*cos(theta)\/2)-cos(k*L\/2)).\/sin(theta));\r\npolar(theta, abs(E))<\/pre>\n
Note that the above is true within an area at a sufficient distance from the antenna known as the far-field of the antenna. Closer to the antenna i.e. in the near-field the E-field expression is a bit more complex.<\/p>\n","protected":false},"excerpt":{"rendered":"
A dipole antenna is a simple antenna that can be built out of electrical wire. The most common dipole antenna is a half wave dipole which is constructed from a piece of wire half wavelength long. The wire is split in the center to connect the feeding wires. The E-field of the antenna has a circular pattern along a plane which cuts the axis of the antenna perpendicularly and is similar to a figure of 8 in a plane along the axis of the antenna [3D pattern]. The exact E-field can be calculated as: The MATLAB code for generating the […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12,20],"tags":[38],"class_list":["post-1407","post","type-post","status-publish","format-standard","hentry","category-ant","category-rand","tag-antenna"],"_links":{"self":[{"href":"https:\/\/www.raymaps.com\/index.php\/wp-json\/wp\/v2\/posts\/1407","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.raymaps.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.raymaps.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.raymaps.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.raymaps.com\/index.php\/wp-json\/wp\/v2\/comments?post=1407"}],"version-history":[{"count":31,"href":"https:\/\/www.raymaps.com\/index.php\/wp-json\/wp\/v2\/posts\/1407\/revisions"}],"predecessor-version":[{"id":1458,"href":"https:\/\/www.raymaps.com\/index.php\/wp-json\/wp\/v2\/posts\/1407\/revisions\/1458"}],"wp:attachment":[{"href":"https:\/\/www.raymaps.com\/index.php\/wp-json\/wp\/v2\/media?parent=1407"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.raymaps.com\/index.php\/wp-json\/wp\/v2\/categories?post=1407"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.raymaps.com\/index.php\/wp-json\/wp\/v2\/tags?post=1407"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}