Two different types of novel dual band antennas suitable for a data communicator device are reported. The first antenna is a dual frequency, dual polarization microstrip patch antenna, capable of generating two distinct frequencies with different polarization characteristics and radiation patterns. This antenna has been intended for coverage of the GSM/Iridium's satellite frequencies. The second antenna modified bent folded monopole antenna having two resonant frequencies, with a frequency separation of 1.9. This antenna could be used in the GSM/DCS1800 frequencies. The limitations of both antennas are also briefly mentioned.