Say in 2050, how do you think the microwave technology will change. I think we might have cordless phones at 150 GHz, Spectrum analyzers covering DC- ultraviolet in microhertz resolution in a picosecond sweep that show both time and frequency domain in a 3D holographic display. In addition we will have signal generators covering DC- Gamma all in one portable unit.
This is hard to predict. Cost and user needs will always affect what products are marketed. I do not think that present products like cordless telephones will go higher in frequency because the higher frequency parts will cost more than thee lower frequency ones. Also the attenuation through building walls will be greater at the higher frequencies.
The other problem with higher frequencies is the antenna beamwidth for a given received signal power becomes narrower as frequency is increased. This puts a limit on systems that are not point to point. It also puts a small limit on point to point systems in the area of mechanical tolerances on antenna pointing with the wind twisting the tower by more than the antenna beamwidth.
I think terahertz would be used for other application like satellite communication, etc. As for wireless communication, lower frequency will be remained but with lower cost and power consumption, robust, better efficieny and performance (data rate of Gbits/s)......
i think when you want to predict you should look for many point of view !!!!!!!!
like chemistry's periodic table ..........
you should consider many element to ...
Maybe new technologies will arise. What about that australian experiment of teleportation (not in the Star Trek sense of the word)? They teleported the characteristics of a photone if I remember correctly. It's a promissing beginning for a new wave in data communication.