Short answer: No, it is absolutely nothing like Schengen. DXB T1 strictly segregates arriving and departing pax. You will deplane, follow the "Connections" signs, and be forced through a transfer security checkpoint before you can go up the escalators to the departure level at Concourse D.

90 minutes is sufficient for D-to-D, provided your inbound from Germany is on time. Just don't stop for a smoke before you clear that checkpoint; the lines can be unpredictable during peak banks.