This invention uses the time tested strength of cables to stiffen long spans. Here is a picture of an actual bridge. Since the carport edge needs to be both held UP and held DOWN there are 2 cables used. Note that the posts on each end must be strong enough to support the entire roof edge and to hold it down.
Note below the span can be over 40 feet – depends on cable strength. The 40 feet was using 1/8 diameter stainless steel cable. The end supports are 12 inches high or 6 inches from center to tip where cable is attached.