Dual band circularly polarized microstrip antenna for IRNSS reference receiver

In satellite communications, Ground stations continuously monitor the navigation signals by one way ranging to determine the orbital parameters of the satellite as a part of TT&C. For achieving navigational functionality a number of ground-based elements are involved. One of the important elements are Range and Integrity monitoring stations which are established at accurately known locations for facilitating one way ranging. In India IRNSS is being established for navigation purpose. The ground segment stations use a dual band antenna in L5 (1.176GHz) and S (2.492GHz) band with common phase center and the stations are named as `IRNSS Range and Integrity Monitoring Stations' (IRIMS). A Dual band circularly polarized antenna with common phase center has been developed for these ground stations to cater to both the IRNSS downlink frequencies. This paper describes the design aspects and measured results of the antenna.