What is the name of low-frequency signal smt "jumper" that goes above RF microstrip?

They used rarely, can't google any photos of them. It looks like U-shaped metal, which used instead of air-wire to go over RF line on a single-layer PCBs. I have seen sometimes 0 Ohm resistors used for this purpose with quarterwave stubs on both ends. But this "jumper" have pretty big gap above RF line.

I don't believe that these jumpers have been designed to bridge microstrip lines, but you find SMT jumpers fitting your description at Keystone. http://www.keyelco.com/category.cfm/.../p/518/id/1206