Do you know of the town Unterberlin, Baden, Germany?

My great great grandfather, Jakob Tubach/Jacob Duback was born there 22 Jan 1822 and emigrated to US 1846-1848. Birth place also listed as Baden Baden, Germany. Married Dorothea Sauer 9 Oct 1853 in Newport, Rhode Island while in US Army at Fort Adams. Parents were Fritz Tubach and Catherina Burnside. Jakob youngest of five children.

Dorothea Sauer b 26 Feb 1839, Wertzburg, Bavaria, Germany. Parents Jacob Sauer (Possibly Francis Peter Sauer)b abt 1811 Band Master 3rd Artillery US Army died in California abt 1859 and Mary Ann unknown maiden name b 1822, Nordheim, Bavaria, Germany (headstone) d 11 Sept 1892 Vancouver, WA. Other children: Annie D md Brown in WA, a son drown in Rhode Island, and Margaret, Joseph.

Have not been able to find Unterberlin on a map.