Beacon Receiver Design And In-situ Antenna Calibration For Q-band Satellite Ground Station

Q-band(30-50GHz)is the near-frequency band of millimeter wave,which has higher frequency,wider bandwidth,higher rate and attracted more attention in the field of satellite communication.Q-band signal wavelength is similar to the size of the material in the atmosphere,and it is easier to be affected by the external environment.Therefore,on the premise of ensuring the link quality,Q-band satellite communication puts forward higher requirements for the design of beacon receiver and the accuracy of antenna installation.Based on the experimental work of the Millimeter Wave Research Group at Aalborg University in Denmark during the visiting period,the design of a low-cost dual-branch beacon receiver is completed,and the antenna calibration method which can be completed in the ENU coordinate system is proposed.The main work in this dissertation are listed as follows:(1)According to the climate characteristics in Denmark and the possible transmission losses in the satellite-ground link,the research was carried out especially considering the influence of rainfall attenuation on the downlink.The satellite communication channel survey and link budget are completed,and the parameter requirements of beacon receiver components are proposed,in order to ensure the safe and reliable operation of satellite beacon receiving system.(2)The design of the dual-branch beacon receiver based on the superheterodyne receiving structure is completed on the condition of considering the cost in all aspects and practical feasibility.The simple in-situ directional antenna is used to replace the complex satellite tracking system,and the combined scheme of space-angle diversity can meet the requirements of Q-band satellite communication links and achieve extensive link coverage.(3)As the signal power received by the antenna is highly sensitive to the variation of satellite position,the calibration scheme of the in-situ antenna pointing angle in the ENU coordinate system is proposed,and the noise reduction strategy is applied to the measured data for experimental verification.The feasibility of this scheme in actual antenna pointing angle calibration is verified by both theory and experiment.Q-band satellite signal receiving research is a complex and systematic work.The design scheme of the beacon receiver and the calibration strategy of the receiving antenna proposed in this paper can provide practical experience for the research of the Q-band satellite link and the construction of the satellite beacon receiving system.