You can search all the ethnomusicology programs here: http://www.ethnomusicology.org/?page=GtP and all the ABET accredited engineering programs in the field you want to study here: http://main.abet.org/aps/Accreditedprogramsearch.aspx and cross reference them. Narrow down based on other intangibles like location, size, weather, etc.
It’s important to know that engineering curricula are packed with requirements as are music curricula. It would be very, very challenging to find the time to double major. Minoring, depending on the school might be more doable.
A third option is to find a school or an associated school that has an instructor you’d like to study privately with. My son, after ruling out conservatory as a primary option, looked seriously at Case Western for engineering because his favorite master class teacher was a professor at Cleveland Institute of Music.
In the end, he concentrated full time on engineering.
Good luck.