An idea to amalgamate GPS and GLONASS to form the best part of GNSS tracking system for mobile robot navigation. The introduction of GNSS made additional satellites visible to localize Mobile robot accurately in both indoor and outdoor application; hence the localization accuracy will be increased in the non-line of sight areas of GPS satellites. This paper explains about an antenna which operates in GPS-1.575 GHz and GLONASS-1.602 GHz system frequency bands. A single layer square patch antenna with size of 45 mm * 45 mm is designed and simulated using Computer Simulation Technology Algorithmic model of the proposed antenna is derived and RLC values of equivalent circuit are identified using MATLAB program. The prototype antenna is fabricated and tested using network analyser for observing the experimental results. The Proposed antenna parameters are compared with simulation, theoretical and existing antenna results. Thus, the findings support that the proposed antenna system could be useful for the localization of car like mobile robot in indoor and outdoor environments.