def copy_signal(signal_glob, source_db, target_db):
    # type: (str, cm.CanMatrix, cm.CanMatrix) -> None
    """
    Copy Signals identified by name from source CAN matrix to target CAN matrix.
    In target CanMatrix the signal is put without frame, just on top level.

    :param signal_glob: Signal glob pattern
    :param source_db: Source CAN matrix
    :param target_db: Destination CAN matrix
    """
    for frame in source_db.frames:
        for signal in frame.glob_signals(signal_glob):
            target_db.add_signal(signal)