Wire antennas coated with magnetically and electrically lossy material

The effect of coating a thin dipole antenna with a thin layer of magnetically and electrically lossy material is considered with respect to the properties of input impedance, current distribution, far-field pattern, bandwidth, radiation efficiency, and effective length. Moment method calculations show that the change in the antenna properties is a strong function of the location and the kind of lossy material applied. The calculated input impedance of a monopole wrapped both fully and partially with different types of lossy materials is shown to agree well with measurements. An approximate semigraphical procedure for impedance calculation is postulated and shown to be useful.