A cellular communication system and mobile device in which the mobile device utilizes a single antenna to handle communications for two or more radios. Each radio is coupled to the antenna by an appropriate filter or the like which routes signals received in different frequency bands to the appropriate radio for processing. By using only one antenna to service multiple radios, problems associated with mutual coupling between multiple antennas can be eliminated. Also, use of a diversity antenna having left and right hand circularly polarized elements provides improved immunity to cross-polarization.