We demonstrate radio frequency (RF) transmission characteristics in a layer stacked manner. Generally, as the number of graphene layers increases, the impedance is reduced and the transmission efficiency of monolayer graphene becomes better than that of chemically synthesized monolayer graphene. Depending on the stacking method, graphene may or may not be well aligned between layers; however, this characteristic affects the RF transmission. Graphene extracted from graphite is well aligned with other layers; however, synthesized graphene is randomly stacked because it is transferred and the layers are not aligned. Scattering parameters and the measured impedance shows that graphene extracted from graphite exhibits better transmission characteristics in the case of single-layer graphene, whereas synthesized graphene shows better transmission characteristics in the case of multiple-layer graphene. We calculated the change in conductivity based on the matched angle between layers of graphene and found that the conductivity was higher when the matching was less, compared to when it was well-matched. These results are also reflected in the impedance extracted from the scattering parameters. It was found that different impedance patterns are formed in single-layer graphene and in multiple layers for multi-layer graphene with stacking methods. This is because the layers are decoupled when they are randomly stacked.
Bibliographical noteFunding Information:
Manuscript received July 17, 2018; revised September 26, 2018; accepted October 19, 2018. Date of publication November 12, 2018; date of current version December 31, 2018. This work was supported in part by the Nano-Material Technology Development Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, in part by the ICT and Future Planning (NRF-2017M3A7B4041987), and in part by the National Center for Optically Assisted Mechanical Systems 2015R1A5A1037668 through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (MEST). The review of this paper was arranged by Associate Editor Shih-Chi Chen. (Whan Kyun Kim, Juyeong Oh, and Hyong Seo Yoon contributed equally to this work.) (Corresponding author: Seong Chan Jun.) W. K. Kim, J. Oh, H. S. Yoon, S. J. Kim, J. Y. Park, and S. C. Jun are with the Yonsei University, Seoul 03722, South Korea (e-mail:, skyblast@yonsei. ac.kr; firstname.lastname@example.org; email@example.com; firstname.lastname@example.org; email@example.com; firstname.lastname@example.org).
All Science Journal Classification (ASJC) codes
- Computer Science Applications
- Electrical and Electronic Engineering