Summary
International Symposium on Antennas and Propagation
2011
Session Number:ThE2
Session:
Number:ThE2-5
Effects of Raindrop Size Distribution on Millimeter Wave Attenuation, XPD and Their Relations
Hajime Fukuchi,
pp.-
Publication Date:2011/10/25
Online ISSN:2188-5079
Summary:
It is well known that rain-induced attenuation value depends on raindrop size distribution(DSD) . As typical DSD, Marshall and Palmer distribution(MP-DSD) has been well used for moderate rain case. Due to rapid measuring technology progress and increase of interest on DSD, more precise DSD model has been proposed using three parameters such as log-normal distribution model or Gamma distribution one(Gamma-DSD). These three parameter DSD models have different features from MP-DSD especially in small raindrop size region. As MP-DSD model adopts exponential function, DSD increases monotonically as diameter of raindrop decreases. On the otherhand, the above three parameter DSD has such feature that DSD has a peak at certain raindrop size value. Due to such difference of DSD in small raindrop size region, it is expected that, especially in millimeter wave bands, propagation characteristics such as attenuation and depolarization have difference between MP-DSD and Gamma-DSD cases. In this paper, I calculate rain-induced attenuation and depolarization at from 8 to 100GHz assuming both MP-DSD and Gamma-DSD using Pruppacher-Pitter type raindrop shape. The relative differences of attenuation and XPD between the results are derived. Moreover, XPD prediction error when one uses the relation between attenuation and XPD which is recommended in ITU Recommendation which was derived under the assumption of MP-DSD.