(Electrical-Communication nanoantennas) A general conclusion of the topic of nanoantennas
Researcher and author: Dr. ( Afshin Rashid)
Note: 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 .
At first glance, nanotube antennas give us the impression that they are similar to Dipole antennas designed in small dimensions. But in fact it is not the case in the main theory of Dipole antennas to determine the distribution of current on the antenna, that the Dipole radius is larger than the skin depth and also the resistance loss is so low that it can be neglected. Due to the fact that the nanodipole L/d is significantly reduced, it becomes unusable . In one-dimensional electrical conductors such as nanotubes, the skin-depth mode is completely eliminated. Because here the electrons are only allowed to move along the length of the conductor, and therefore the current distribution is effectively one-dimensional. In addition to the fact that electrons move in only one dimension, two important Dicker problems also occur, large inductance and resistance. These characteristics create a very different behavior for nanotube antennas compared to classical antennas. The main difference is that the current distribution is alternating with a wavelength that is 100 times smaller than the free space wavelength for a certain thermal frequency. The wavelength of current distribution depends on the wave speed in that mode. If the speed of the wave is the same as the speed of light, the wavelength of the current distribution is the wavelength of electromagnetic waves in free space. On the other hand, the wave speed in nanotubes is about one hundred times lower than the speed of light. This is because in circuit theory, the wave speed is equal to the inverse of the square root of the capacitive capacitance per unit length multiplied by the inductive capacitance per unit length.
The kinetic inductance per unit length of the nanotube is ten thousand times greater than the magnetic inductance per unit length of conventional antennas. Therefore, the speed of the wave will be 100 times smaller than the speed of light. The efficiency of a classic nanotube antenna is around -90dB, which is due to resistive losses. Meanwhile, the dimensions of the antenna and nano system or nano sensor set, operating frequency, power losses, the scope and dimensions of the sensor network, the structure and facilities of the feeding system and the physical communication platform between different parts of a nano system , major factors and parameters are that each of them is decisive in a way and determines the ability to build and the performance of the final system. Graphene structures can be used to make nano antennas and this valuable structure can play a very important role. Fabrication of nano antennas in various applications of telecommunication and communication systems In common with nanoscale systems, there are new fields and functions of basic nanoelectronics equipment and telecommunication systems.
Conclusion:
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 .
Researcher and author: Dr. ( Afshin Rashid)
Specialized doctorate in nano-microelectronics