But, you don't need a dubblebufferred Frame, because, if you want to draw own Graphics you should use a class that extends JComponent or simply extend the JPanel. This components can be set to doubblebuffered.
Because of the multiplatform thing of the awt, the JFrame must follow some rules and there is simply no need to doublebuffer the Frame.
(If I remember correctly the basic Frame of the awt was also not doublebuffered. If you wanted to paint buffered Graphics on it you had to write an own Graphics buffer and flip it by yourselfs onto the screen.)