In this paper, two antenna designs using active components are presented for reflection coefficient tunability. The antennas are designed within the scope of the Artemos project and use MEMS switches and BST tunable capacitors internally available in the project. The first antenna uses an SPDT MEMS switch to select between one of the two target frequency bands (700-960MHz and 1.7-2.7GHz). The second antenna uses a tunable capacitor with a tuning range of 2.5-4pF, to frequency tune the reflection coefficient between 700 and 960MHz., The coverage of the 1.7-2.7GHz band is achieved by a monopole antenna who is fed separately.