Methods of microwave physics in developing THz frequency range

The application of the microwave approach to the developing of the terahertz (THz) frequency range allowed producing the set of precise methods and devices for various applications. The midpoint of the development was the using of the mixers and multipliers on the quantum semiconductor superlattices which allow more effective signal transformation in comparison with usually used devices based on Schottky diodes. As a result the unique family of the frequency synthesizers based on the backward wave oscillators operating in the frequency range of 667 ÷ 1100 GHz was produced. Besides, the application of the non-stationary microwave spectroscopy together with the components of solid state nanoelectronics allowed to realize the solid state spectrometer of the THz frequency range, working in the fast sweeping of the frequency. The high sensitivity and spectral resolution allows using the spectrometer developed for various applications. The results of the spectrometer applications for the purposes of medicine and biology, as well as for hi-tech and safety systems are presented.