TERAHERTZ Communications



Terahertz communications


Features of millimeter and terahertz waves.gif





R&D directions in millimeter and terahertz waves..gif



The various advantages of the application of this band of electromagnetic spectrum

in the communication system are summarized as follows:
(a) Microwave band is almost all pre-occupied by different services and its bandwidth is limited.

      In place of this, the terahertz can offer a wider bandwidth.
(b) The diffraction of the THz wave is low in comparison to that of the microwave and millimeter wave,

      which is the advantageous in the line-of-sight (LOS) point-to-point link.
(c) In the recent proposal the maximum allocated frequency is 250 GHz and thereafter it is license free.
(d) This band is comparatively secure, especially in the spread spectrum technology.
(e) In comparison to infrared, THz has low attenuation of the signal in certain atmospheric conditions like fog.
(f) Time varying refractive index of the atmospheric path increases the scintillation effect in the infrared link

     and it can be reduced in the THz communication link.
(g) It is a viable solution to the last and first mile problem.
(h) The significant development to enhance the data rate in the infrared wireless communication is slow due to

      the requirement of the advanced modulation formats like orthogonal frequency division multiplexing (OFDM),

      coherent transmission and requirement of multiple-input-multiple-output (MIMO) technique.