| Popis: |
In recent years, the electromagnetic environment has radically changed worldwide because of numerous sources of high-power electromagnetic signals, which interfere with information-carrying signals and, thereby, considerably distort them. As a result, a wide-band background electromagnetic field is present in the environment, with its strength often much higher than that of natural electromagnetic fields. Such a situation places more stringent requirement on transmitting/ receiving equipment and its operational maintenance. Therefore, of primary concern in the design of modern communications is to ensure a high immunity against different types of noise. A solution to this problem may lie in using those systems handling fractal ultra wideband (FUWB) signals. This type of UWB signals has multiband fractal spectra with exact top and lower boundaries. FUWB signals were created with maximum width of spectrum equal to 640 MHz. FUWB signals are not only ensuring a high protection of information against electromagnetic fields but also prevent unauthorized. Thereto multiband fractal antennas and fractal filters were developed. Fractal signals were generated and transmitted (in air or via 50 m cable) with a carrier frequency at 2 GHz and more. Using FWB signals and recent advances in electronic technologies a new fractal communication system was created and successful experiments were carried out. |
