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In this paper, the wave propagation of a graphene based conductor (GBC) transmission line (TL) and its comparison with a copper TL on a conformal surface is presented. An investigation of the coupling between parallel GBC TLs and copper TLs is also summarized in this work. A 150 mm long TL was initially manufactured on a flexible substrate and the wave propagation characteristics were investigated on a conformal surface. Then, a microstrip copper TL was manufactured and the wave propagation on a conformal surface was compared with the GBC TL. Also, prototypes with various combinations of two parallel TLs (GBC — GBC TLs, GBC TL — Copper TLs, etc.) were manufactured and studied for comparison. It was shown that the wave propagation properties of a given GBC TL on a conformal surface were similar to that of a copper TL over the frequency band of 100 KHz to 8.5 GHz. Moreover, results of the near- and far-end coupling showed that the GBC TLs can be used as an alternative to copper TLs as they can provide better coupling on a conformal surface.

In this paper, the use of a carbon microfiber bundle (CMB) is investigated for manufacturing a monopole antenna. In particular, the radiating properties of a carbon microfiber bundle, having filaments of 7 μm in diameter, were studied as a monopole. The proposed monopole was mounted vertically on two separate types of ground plane, i.e., a small copper and a large aluminum ground plane. The monopole design was modeled in HFSS. To analyze the radiation characteristics of the microfibers and its shift in the resonant frequency, CMB monopole antenna prototypes with various lengths were manufactured and tested in an anechoic chamber. Overall, the simulation results agreed well with the measured results. Prototypes manufactured on the larger ground plane showed higher gain as compared to those on the smaller ground plane, with no significant difference in the matching characteristics. Overall, it was demonstrated that the light weight, low cost carbon microfiber bundle can be used to design an antenna for a range of resonant frequencies.

In this paper, a novel ultra-wide band (UWB) antenna comprised of graphene-based conductor (GBC) sheets is proposed. The proposed antenna is designed and simulated in a full-wave 3D EM solver and fabricated using a GBC sheet on a TMM4 substrate. Simulations and measurement results agree well, showing an overall matching from 2.65 to 10 GHz. Bandwidth and gain of the proposed antenna were also compared with a conventional UWB antenna made of copper. Impedance matching and the bandwidth of the conventional antenna were found better than the proposed GBC antenna, owing to variations in the material properties. Overall though, the results showed that the GBC sheet has good UWB characteristics and therefore can be used for UWB applications.