METALS are commonly used in antenna structures for the
radiating elements and the ground plane. However, for
some applications, cost, fabrication procedure, weight, or corrosion
resistance can limit the usefulness of metal antennas. Some
recent studies have used various composite materials as replacements
for metals [1]–[5]. In [1], a conducting-polymer patch
antenna is proposed. Silver nanoparticle ink [2] and metallo-organic
conductive ink [3] have been used to prepare a highly conductive
material. In [4], metallized foam is used to make a microstrip-
patch antenna.
Advanced carbon-fiber composite (CFC) materials are
being used in the aerospace industry as a replacement for
metals [5], [6] because of their higher strength, lower cost, and
lighter weight. There are various kinds of CFCs: reinforced
continuous carbon fibers (RCCFs) [5], short carbon fibers
(SCFs), carbon black (CB), and carbon nanotube (CNT) [6]. In
[7] and [8], we investigated the use of carbon fiber materials for
the radiating element of a radio frequency identification (RFID)
antenna. It was observed that CFC can be efficiently used in