International Journal of Advanced Networking and Applications

Yahaya Yunisa ¹, Zhimwang Jangfa Timothy ², Ogherohwo Enoh Pius , Ibrahim Aminu , Shaka Oghenemega Samuel , Frank, Lagbegha-ebi Mercy

Affiliations
1 Department of Electrical/Electronics Technology, Kogi State College of Education (Technical) Kabba,Kogi State, NG
2 Department of Physics, Federal University Lokoja, NG

Abstract

This study presents the evaluation of signal strength and quality of a ku-band satellite downlink signals during raining season in Guinea Savanna region of Nigeria. Rain rate data and ku-band signal over Jos were retrieved from the Nigeria Meteorological Agency (NIMET). Rain rate data was measured using Davis Vantage Vue weather station while microwave signal were obtained using spectrum analyzer. The measured data were analyzed using Microsoft office excel. Rainfall is broadly classified into two types: stratiform (drizzle: ≤5mm/hr and widespread: >5≤25mm/hr) and convection (shower: >25≤50mm/hr and thunderstorm: >50mm/hr). Results were calculated based on ITU-Recommendations P.618-12 and P.838. The results obtained revealed that the effect of rain on signal strength and quality on a ku-band link depend on the rain type and duration of rainfall. The effect of drizzle (≤5mm/hr) on the ku-band link is not significant regardless the duration of rainfall. The results also shows that severe signal losses above 60dB were obtained under shower (>25≤50mm/hr) and thunderstorm (>50mm/hr). Also, widespread (>5≤25mm/hr) that prevailed for a longer period causes severe signal losses. This is to say that lower rain rate of about 25mm/hr that prevailed for a very long time have significant effect on Kuband link. The results of this study will serve as crucial design parameters for communication systems engineers for providing fade margins and developing accurate fade mitigation techniques (FMTs) for the Guinea Savanna region of Nigeria. It was observed from this study that the experimental studies within the Ku-band frequency are getting over exhausted. Therefore, experimental studied in the region of higher band like K and Ka are highly recommended.

Keywords

Ku-Band, Downlink, Signal Quality, Signal Strength and Signal Loss.

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Zhimwang Jangfa Timothy ¹, Shaka Oghenemega Samuel ², Lagbegha-ebi Mercy Frank ³, Ibrahim Aminu ⁴, Yahaya Yunisa ⁵

Affiliations
1 Department of Physics, Federal University Lokoja, NG
2 Department of Science Laboratory Technology (Physics with Electronics), Delta State University, Abraka, NG
3 Department of General Studies, International Institute of Tourism and Hospitality, Yenagoa, NG
4 Centre for Satellite Technology Development, Abuja, NG
5 Department of Electrical/Electronics Technology, Kogi State College of Education (Technical) Kabba, NG

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 (9.8965° N, 8.8583° E; 1192 meters) with Maximum, Average and Minimum Temperatures of 29.8°C, 22.8°C and 17°C 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.

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