ABSTRACT

This paper presents the analysis of frequency and polarization scaling on rain attenuated signal of a KU-Band link. The study was carried out in Jos, Plateau state, Nigeria (9.89650 N, 8.85830 E; 1192 meters) with Maximum, Average and Minimum Temperatures of 29.80C, 22.80C and 170C respectively. Data were obtained for the months of May, June, July, August, September and October 2020.Davis Vantage Vue weather station was used to measured and record one-minute rain-rates from a minimum of 0.8 mm/h up to a value of 460 mm/h, with an accuracy of 0.2 mm/h. The precipitation data, with date and time is captured on the micro-chip of the wireless electronic data logger, which, when calibrated, logs on data every minute. The down converted Ku-band signal was fed into the digital satellite meter and a spectrum analyzer for signal level analysis, logging and recording samples of viewed spectrum over finite periods of time on a computer system. Both satellite signal and precipitation measurements were done concurrently. Data were analyzed using Microsoft excel and results were obtained based on ITU-R model. Results obtained revealed that rain attenuated signal for vertical and horizontal polarization varies for different rain rate and months under reviewed. For the month of May 2020, rain attenuated signal is more severe from rain rate of 100mm/hr with the highest rain attenuation of 25.57dB, 30.37dB, and 39.84dB at frequencies of 12GHz, 15GHz and 18GHz respectively while the rain attenuated signal for vertical polarization is more severe from 80mm/hr with highest recorded rain attenuation of 27.96dB, 40.33dB and 45.71dB at frequencies of 12GHz, 15GHz and 18GHz respectively. For the month of July 2020, the results shows that rain attenuated signal for vertical polarization is more severe from rain rate of 80mm/hr with the highest rain attenuation of 60.57dB, 73.37dB, and 100.84dB for frequencies of 12GHz, 15GHz, and 18GHz respectively. At Horizontal polarization, signal losses are more severe from 60mm/hr. The results further proves that frequency and polarization scaling of rain attenuated signalare major factors to consider when designing a microwave link budget especially in the study area that experiences high amount of rainfall annually

Keywords: - KU-Band, Electromagnetic Frequency, Signal Polarization, Signal Loss and Rain attenuation