The technique of obtaining multipole representation of radiation from antennas using quasi-static near fields is presented. For this wire antennas on PEC sphere, patch antennas and horn antennas are considered. In this technique the radial components of the near fields on a sphere enclosing the antenna are calculated using the static laws. In turn the multipole coefficients representing the radiation are calculated. The obtained results are validated with HFSS simulations and the deviations are explained. Next, the dynamic communication link aspects of IITMSAT (IIT Madras student Satellite) is presented. The LEO satellite has a limited Attitude Determination and Control System (ADCS) ability to align one of its body axes with the geomagnetic field in the orbit. Calculations of the link strengths for uplink and downlink along the typical passes of the satellite above a ground station located in Chennai are presented. For this the geomagnetic field at the altitude of the orbit is taken into account . This analysis helps in choosing the polarization (LHCP or RHCP) for uplink and stresses the need for polarization diversity at the ground station for downlink.