As long as new technologies appear, the need for smaller and more customizable antennas has become a reality. When the first smartwatches came out, they were only able to work if connected to a smartphone through Bluetooth. Therefore, the next step in the design of this devices is making them able to be autonomous.This study focuses on designinga small enough antennasystemto fit in a wearable device (i.e. a smartwatch) which is also capable of working with LTE bands.To do so, the proposed antenna will be a radiating system composed by a Antenna boosterand a radiating surface as small as possible.Multiple candidates have been designed and studied, and their properties have been measured in order to find out how good they fix the described problem.This project, as long as the research done, has been supervised by PhD. Jaume Anguera and PhD. Aurora Andúja