Microwave absorbing properties of activated carbon-fiber felt dipole array/epoxy resin composites

Microwave absorbing properties of the composites containing activated carbon-fiber felt dipole arrays (ACFFDAs) were investigated. The results show that the absorbing performances of the composites containing ACFFDAs are affected greatly by the dimension parameters of the arrays, the resistance connecting the two arms and the materials of the dipoles. The absorption of the composites containing ACFFDAs presents anisotropy. When the dipoles are parallel to the incident electric field, the composites show better absorbing effect. The absorbing properties rise at first and then fall with increasing the resistance connecting arms or the space between dipoles. In this work, when the dipoles are parallel to the incident electric field, the composite obtains a reflection loss below –10 dB over 12.2 GHz and the minimum value reaches –32 dB. The bandwidth below –10 dB increases with increasing the length of the arms when the dipoles are parallel to the incident electric field. The bandwidth below –10 dB is 13.1 GHz when the length of the arms is 85 mm. Compared with copper plate, the dipole arrays whose arms are made of activated carbon-fiber felt exhibit better absorption properties.