The depolarization effects of Earth-Space link at MMW Bands
The depolarization effects of Earth-Space link at MMW Bands and their mechanisms are analysed. The models to evaluate XPD induced by clear atmosphere, rain, ice crystals, snow, sand-dust storm and ionized layer are summarized and analysed. The methods to calculate total XPD including the influence of transmitting antenna are discussed. The results given in this paper are important for frequency resue and depolarization MIMO techniques.
La réutilisation des fréquences en polarisations croisées avec diversité d’espace sur 50 km a 7 GHz
AnalyseL’auteur présente les résultats de mesures de variations du découplage de polarisation obtenues sur une liaison hertzienne de 50 km fonctionnant à 7 GHz, en période d’affaiblissements par trajets multiples. Après avoir rappelé l’influence d’un brouilleur sur un signal modulé par déplacement de phase, il donne des résultats de calcul de la qualité d’un canal numérique en démodulation différentielle, sur une liaison qui utiliserait les deux polarisations rectilignes à la même fréquence. La diversité optimale, ou avec seuil de commutation, améliore la qualité d’une liaison fonctionnant en double polarisation.AbstractThe author present experimental data describing the statistics of 7 GHz polarization discrimination during multipath fading obtained on a 50 km path. He gives a formulation of cross polarization interference on aPSKsignal, and calculatesQDPSKchannel quality on a link with dual polarized frequency. Switching space diversity, without or with threshold improve dual polarization radio link quality.
Studies on the composition, quality and processing of triticale. Part II. Mineral composition of grain and flour.
Mineral composition of grain and flour in 14 promising triticale strains from India are reported. The mean values for whole grain, i.e. Ca (0.47 mg/g), P (2.70 mg/g), K 4.60 mg/g, Na (352 micrograms/g), Zn (41.6 micrograms/g), Cu (7.0 micrograms/g), Fe (73.4 micrograms/g) and Mn (33.6 micrograms/g) were obtained as compared to those of flour, i.e. Ca (0.27 mg/g), P (0.97 mg/g), K (1.64 mg/g), Na (231 micrograms/g), Zn (26 micrograms/g), Cu (4.0 micrograms/g) and Mn (10.5 micrograms/g), respectively. These values were found to be considerably higher than those of wheat. Highly significant positive correlations of ash with sodium and zinc in whole grain were observed. In the case of triticale flour, highly significant positive correlations of ash with manganese, phosphorus and potassium were obtained.