An initial study on using carbon microfiber transmission lines in conformal array networks

In this paper, an initial study on the possible use of carbon microfibers as a transmission line (TL) feed network in conformal microstrip antenna arrays was conducted. Initially, a 12.0 cm long 50 Ω microfiber transmission line was manufactured and the wave propagation properties were measured. These characteristics were then compared to the propagation properties of a traditional copper microstrip TL with the same length. Once these propagation characteristics were determined, two parallel TLs with a separation of 4.0 mm were then manufactured to investigate the unwanted coupling that may occur in a feed network of an array. One of these TLs was a copper microstrip line and one was a microfiber TL with similar dimensions. Overall, it has been shown that the microfiber TLs support wave propagation in a manner similar to the copper microstrip TLs but the attenuation constant was larger, as the 3 dB point was at 2.5 GHz. Also it was evident from the measurements that the microfiber TLs were more immune to coupling at high frequencies. The results demonstrated that these properties made microfiber TLs a good possible candidate for the feed network of a conformal microstrip antenna array.