The paper investigates the antenna design to be applied in the ESPACENET sensor node. The project involves a network of autonomous pico satellites working at a large number of communication standards and as passive radar sensors for earth observation. They would form the next generation of "eyes in the skies"; looking out for natural disasters, helping in the survey and effective utilization of natural resources and also form a seamless network of global communication which will have the potential to evolve itself with the growing demands of tomorrow?s world. We discuss the need for a multiple frequency broadband antenna which would help cover a larger range of microwave frequencies enabling the antenna to work as both a communications antenna and a sensor device.