Abstract
This paper describes a rectangular spiral antenna backed by a conducting plane of finite extent. The distance between the spiral and the conducting plane is chosen to be extremely small: 0.07 wavelength at a test frequency of 3 GHz. For analysis, the finite-difference time-domain (FDTD) method is used. The radiation characteristics, including the current distribution, input impedance, radiation pattern, axial ratio, and gain, are revealed and discussed. It is found that absorbing materials inserted into the space between the conducting plane and the peripheral region of the spiral contribute to the wideband frequency characteristics of the axial ratio and input impedance.
Get full access to this article
View all access options for this article.