A new generation of antennas and microwave circuits based on carbon-fiber nanocomposites is presented for future wearable/flexible wireless technology and smart textiles. We used two kinds of nanocomposites, namely reinforced continuous carbon-fiber composite (RCCFC) and carbon nanotube (CNT). It is shown by exploiting the anisotropy of conductivity in RCCFC, new and exotic antenna characteristics such as reconfigurable designs can be achieved. By proposing a novel fabrication method, arbitrarily-shaped antennas made of conductive CNT buckypapers are built and tested.