Wyniki wyszukiwania - BazTech

Ograniczanie wyników

1 Acta Geophysica

1 2019

Znaleziono wyników: 1

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: tłumienie chmur

Sortuj według:

Ogranicz wyniki do:

Precipitation and other propagation impairments effects at microwave and millimeter wave bands: a mini survey

Kotamraju Sarat Kumar, Korada Ch Sri Kavya

Acta Geophysica

2019

Vol. 67, no. 2

703--719

The current past has seen a sensational increment in the utilization of satellites for the applications like navigation, entertainment, media transmission, remote sensing, mobile communications, weather forecasting, defense and other purposes. These applications are assigned in the microwave and millimeter wave bands, which offer higher information transfer possibility in lesser time and use very small antennas and devices by ensuring secured and effective communications. However, beyond the 10 GHz range of frequencies these applications are generally subjected to signal losses due to various atmospheric parameters like rain, clouds, fog, hail ice and other applicable phenomena. The main factor for the signal degradation is the rainfall. The attenuation caused by rain increases with frequency, as there is increased absorption of the RF energy at higher frequencies due to water drops present along the path of the transmission; hence, the signal attenuation is more in higher-frequency bands. The other factors that induce losses in the signal are the clouds, gases present in the lower atmosphere and the different layers in the atmosphere that cause scintillation and the system losses and cable losses. This survey article abridges all outcomes related to propagation impairments and attenuation aspects at microwave and millimeter wave frequencies covering the studies of various researchers in last three decades. In addition, few of the models developed by various researchers were listed along with model parameters which are useful for the propagation engineers and others who are interested in this specialization.