IEEE Applied Electromagnetics Conference, MIT, Aurangabad, Maharashtra, 20.12. 2017.
The quest for higher power and frequency in commercial, military, and space applications have pushed the microwave, mm-wave and sub-mm-wave technologies to a much higher level. The spectrum between 300 MHz to 30 GHz is referred to as the microwave band; 30 GHz and 300 GHz is referred to as the mm-wave band, and the 300 GHz to 3000 GHz band is called by electronics engineers as sub-mm-wave and by the optics engineers as Thz band. Starting from the radio, microwave oven and satellite and imaging applications all depend on this spectrum of frequencies. Recently, directed energy weapons using high powered microwaves is becoming strategic game changers in defense applications as they can blow off enemy drones and can destroy enemy ballistic missiles in their boost phase itself. THz wave technologies which are at the borderline between electronics and photonics are used in imaging; non-invasive and non-destructive inspection using spectroscopy due to their low photon energies, that is one million times weaker than x-rays and directivity similar to laser light. They can be used in surveillance, such as security screening, to uncover concealed weapons on a person, remotely.