I have found a picture of the Mitre-tiara that used to be worn by the Patriarch of Lisbon as a privilege given to him. I have also found a picture of the sedia gestatoria that the same Patriarch was allowed to have and preach from, but he could not use it for procession or things like that - just preach (I'm pretty sure).
This Mitre, from far away, is supposed to resemble a (papal) Tiara. That is the purpose of the three lines of jewls on it. Of course, the top will always look like a Mitre, even from far away, because it is a Mitre! However, the tiara (very different from the Papal one) is still part of coat of arms of the Patriarch of Lisbon. Check their website!
Now, this is a picture (very small, though) of the sedia and the flabella used by the Patriarch. The sedia looks smaller than the Papal one and not as wide. The flabella are much smaller, too.
*In a previous post, I showed a picture of the traditional Mitre-tiara of the Patriarch of Lisbon. (This was one of the liturgical privileges given to them in the past - many of them at the insistent request of King João). The above picture shows a *modern* Mitre-tiara worn by Patriarch Antonio Ribeiro.
Notice the three bands, which are supposed to resemble the 3 rings of a tiara. They could do much better than that!
Now, this is a picture of the Fanon worn by the Patriarch of Lisbon in the past - another liturgical privilege granted to them by Popes. I do not think that they wear the Fanon anymore.