Abstract

In general, in order to receive the electromagnetic wave in the space, the dimensions of the antenna must be in the order of the wavelength of the input to its surface. Due to the very small dimensions of nano sensors, nano antennas need to have a very high working frequency to be usable. The use of graphene helps to solve this problem to a great extent. The speed of propagation of waves in CNTs and GNRs can be 100 times lower than its speed in vacuum, and this is related to the physical structure, temperature and energy. Based on this, the resonance frequency of graphene-based nano-antennas can be two orders of magnitude lower than nano-antennas based on nano-carbon materials. It has been mathematically and theoretically proven that a quasi-metallic carbon nanotube can emit terahertz radiation when a time-varying voltage is applied to its sides. One of the most important parameters of any nano antenna is the current distribution on it. This characteristic determines the radiation pattern, radiation resistance and reactance and many important characteristics of the antenna. Despite the possibilities of making nanotubes with a length of several centimeters, it is possible to make electrical conductors with a length-to-width ratio of the order of 10^7. has it. At first glance, nanotube antennas give us the impression that they are similar to Dipole antennas designed in small dimensions.