A.M. Lerer, V.V. Makhno, P.V. Makhno, G.A. Shurov
Nowadays the Carbon nanotubes (CNT) application as nanoantennas in centi- and millimeter wavelength ranges is being studied thoroughly. Such antennas can be used to interconnect between nanoelectronic circuits and macroscopic devices. Because of CNTs have larger electric length than metallic vibrators CNT’s of 20-50 mkm length do resonate in millimeter wavelength range.
The main objective of present work is to determine the circumstances to lower working frequency of CNT vibrator – by means of increase of it’s length and by their placing in dielectric. The effective method of carbon nanotube antennas' parameters calculation was developed. At solving the integral equation (IE) with logarithmic singularity was obtained. After analytical transformation of static singular part of the kernel the transformed IE was solved by means of collocation method. The investigation of input impedance for the systems of parallel radiating nanotubes has shown that an increase of antennas length leads to an increase of number of resonances in the frequency range under investigation and simultaneously leads to efficiency drop. Thus consequently it’s not possible to reach efficient radiation at centimeter frequency range by simply increasing of antennas' dimensions. But placing of CNT in dielectric it’s possible to decrease the resonance frequency at the same physical dimensions of antenna. The use of system of parallel nanotubes leads to appearance of intermediate extremums, which become less expressed if the distance between nanotubes is increased. To increase the radiation efficiency of nanotubes it seems reasonable to use several nanotubes, distant one from another on the distance of CNT's radius' order. Using the systems of parallel nanotubes it's also possible to create directional antennas.