A redundant transponder array for a radio-over-fiber (RoF) optical fiber cable is disclosed. The redundant transponder array includes two or more transponders having an antenna system. The antenna system has first and second antennas adapted to form first and second substantially co-located picocells when operated at respective first and second frequencies. The second antenna is adapted to form a picocell that extends into the adjacent picocell when operated at the first frequency. A transponder thus can serve as a backup transponder to a failed adjacent transponder by redirecting the first-frequency signal sent to the failed transponder to the second antenna of the adjacent transponder.