CREATE TABLE table_80153 ("Year" TEXT, "Men's singles" TEXT, "Women's singles" TEXT, "Men's doubles" TEXT, "Women's doubles" TEXT, "Mixed doubles" TEXT)

Who won the Mixed doubles when Juliane Schenk won the Women's Singles?
SELECT "Mixed doubles" FROM table_80153 WHERE "Women's singles" = 'juliane schenk'
SELECT "Mixed doubles" FROM "table_80153" WHERE "Women's singles" = 'juliane schenk'