Difference between nanotube antennas and classic antennas ( wave speed in nanotubes is about one hundred times slower than the speed of light)

The main difference between nanotube antennas and classical antennas is that if the wave speed is the speed of light, the current distribution wavelength is the wavelength of electromagnetic waves in free space. On the other hand, the wave speed in nanotubes is about a hundred times slower than the speed of light. This is because in circuit theory, the wave speed is equal to the inverse square root of the capacitive capacitance per unit length multiplied by the inductive capacitance per unit length .Nano-networks have greater communication and processing potentials that overcome the limitations of independent nano-devices through the cooperation of nano-devices. One of the problems that has not yet been well solved in nanotechnology is how to establish electrical communication between nano-electronic devices and the macroscopic world without losing the capabilities of these nano-elements. One of these new areas and functions of nano-technology is nano-antennas , which are used in various fields such as nano-sensors, communication nano-networks, electrical energy generation and other similar topics and are considered as one of the current areas of nano-technology development. At the nano-scale, graphene-based antennas are used to transmit EM waves. Graphene is a very thin single-atom sheet of confined carbon atoms placed on a crystal lattice . Given the very small dimensions of nano-sensors, nano-antennas need to have a very high operating frequency in order to be usable. However, the use of graphene helps to solve this problem to a large extent. With the development of nanoscale device fabrication technology, it has become possible to fabricate nanoantennas and use them in various applications. Communication between nanodevices is a major challenge related to the development of nanoantennas and related electromagnetic receivers. Reducing the size of traditional antennas to hundreds of nanometers leads to very high operating frequencies . At THz band frequencies, the very large bandwidth available leads to much higher path loss than lower frequency bands . Nanoantennas can be made from metallic materials such as silver , aluminum, chromium , gold, and copper, or they can be made from new materials such as CNTs and graphene, which are attractive choices for nanoantennas. Using graphene to fabricate antennas can overcome size and communication limitations. In addition, the resonant frequency of nanoantennas based on graphene can be up to two orders of magnitude larger than that of nanoantennas made with other materials.