Hermann Minkowski (died January 12, 1909) had two daughters and one of his sons-in-law was Reinhold Rudenberg who patented carrier current communications
Hermann Minkowski (/mkfski, -kf-/; German: [mkfski; 22 June 1864  12 January 1909) was a German mathematician of Polish-Jewish descent and professor at Konigsberg, Zurich and Gottingen. He married Auguste Adler in 1897 with whom he had two daughters; the electrical engineer and inventor Reinhold Rudenberg was his son-in-law. Among his contributions were: Carrier current communications (patent) 
