Development of Wireless Communication Systems in the Subterahertz Frequency Range

The subterahertz and terahertz frequency ranges are promising for the creation of high-speed wireless communication systems because of the possibility to achieve a bandwidth of about several dozen gigahertz, which ensures a high channel capacity. However, rapid attenuation of a signal during its propagation in the atmosphere complicates the operation of communication systems in these ranges. The use of fixed narrow-beam antennas with a high power gain provides a direct surface communication distance of up to a few kilometers. The communication distance limitation can be partially removed by decreasing the frequency down to 200 GHz and narrowing the channel bandwidth down to a few gigahertz. In this paper, we present a radically new approach that was developed to create a wideband (up to one gigahertz) communication channel based on rapid modulation of a centimeter wavelength signal followed by the carrier-frequency multiplication up to 230 GHz without the modulating-signal distortion. This approach was not used in the previous communication systems. The model of a transmit–receive system (200–220 GHz) based on modern semiconductor devices is described in detail. The possibility of digital signal transmission at a speed of up to 1 Gbit/s is experimentally shown. According to calculations, an output power of the transmitter about several hundreds of microwatt is enough for data transmission to a distance of up to 1.5 km with an antenna gain of no less than 50 dB.