The Jiddistik department of Trier University is part of the Germanics department. As the website explains (my translations):

" Jiddistik in Germany does not concentrate on the Yiddish literature and language of Eastern Europe but focuses on Yiddish language and literature within the German language region, so-called Western Yiddish, for which a knowledge of the German language and its history are thus indispensable. Western Yiddish is studied from its beginnings in the Middle Ages until its demise in the wake of the Enlightenment and the remnants that are still present in the German language. Research focuses on history of grammar, semantics, lexicography, editions of older texts, contrasts between Yiddish and German language history, Yiddish-German linguistic relations and the history of science of Jiddistik."

The department also published a journal called Jiddistik Mitteilungen and organises, together with the Abteilung für Jiddische Kultur, Sprache und Literatur at Düsseldorf University, an annual symposium in Yiddish Studies.