The Phonix D.I was the second design developed by the Phonix Flugzeug-Werke based on Hansa-Brandenburg D.I design which it has produced under licence. The D.I was a single-seat biplane fighter with improvements over the original Hansa-Brandenburg design which included more efficient wings, a more powerful engine and structural improvements.

The D.II variant included balanced elevators and ailerons on the upper wings.