Input Impedance over Frequency of a Half-Wave Dipole - Lesson 2

This lesson discusses the variation in input impedance that is seen at the feed of a dipole antenna as the driving frequency changes.  We will see that the antenna experiences a resonance – an input impedance with zero reactance – at approximately the frequency where its length is equal to half a wavelength, and also at integer multiples of this frequency.  The real part of the input impedance also varies with respect to frequency.  We will look at the equations that describe this variation, and also at several illustrative plots.  This lesson is part of the Ansys Innovation Course: Frequency Characteristics of the Half-Wave Dipole. To access this and all of our free, online courses — featuring additional videos, quizzes and handouts — visit Ansys Innovation Courses at This course was created for Ansys Innovation Courses by Dr. Kathryn Leigh Smith, Assistant Professor, UNC-Charlotte in partnership with Ansys.