Why the Star of David on the Yellow Badge?

Following is my note to the article about the Yellow Badge in Wikipedia

This entry doesn’t explain why the Nazis designed the yellow badge in the shape of a Star of David and not in any other shape. It also doesn’t describe who decided to design the yellow badge, where and when.
To fill these gaps see: “Under the Nazis the term "yellow badge" first appeared in Robert Weltsch's article "Tragt ihn mit Stolz, den gelben Fleck" ("Wear the Yellow Badge with Pride"), published in the Judische Rundschau on April 4, 1933, in reaction to the anti - Jewish boycott of April 1, 1933. At that point no official Jewish sign was in existence and there were no plans to introduce such a sign. Weltsch was apparently referring to the slanderous and abusive inscriptions painted on the windows of Jewish - owned stores and businesses in "Operation Boycott" of April 1, and the relapse to medieval times that it signified.
The proposal to impose a distinctive mark on the Jews was first made by Reinhard Heydrich at a meeting held in the wake of the Kristallnacht pogrom, in November 1938.