Full-wave evaluation of carbon nanotubes as microwave interconnects

Microwave interconnect configurations composed of single wall carbon nanotubes (CNTs) are studied in this paper. Specifically, an atomic layer deposition (ALD) enabled nano-coaxial line with individual CNTs comprising the inner conductor, CNT Goubau line with ALD enabled alumina coating, a nano-coaxial line with inner conductor composed of CNT bundles, and Goubau lines of CNT bundles are discussed. The characteristic impedance and losses of these interconnects are compared with the similar size copper-based transmission lines. Full wave simulations with incorporated quantum effects are conducted using finite element and method of moments tools ANSYS HFSS ¹ and EMSS FEKO¹, respectively. A thorough modeling validation, interconnect design and analysis are carried out over the wide microwave spectrum. Obtained results clearly show that although their inherent loss and impedance are high, the CNT interconnects can indeed outperform their copper counterparts with lower loss and impedance, and that observation is reinforced with decreasing the CNT radius.