The German Navy has said that it will replace its 3 Type 124 anti-air warfare frigates with 6 ships of the new Type 127 class, which will likely be based around America's Aegis Combat System in order to defeat ballistic missile threats. Responding to the requirements, German shipyards have pitched their first design proposals – and they're truly massive: The new frigate could be up to 220 m (722 ft) in length and displace some 12,000 tons. Her main armaments would consist of about 80 VLS cells, 16 anti-ship missiles and a 127/64 main gun. (Source, German, Paywall)
In further news, Germany also intends to buy six (not four) Type 126 frigates, now wholly configured for anti-submarine warfare. One lightly armed Type 125 frigate and up to four Type 130 corvettes will be retired early due to the new threat environment, the remaining modernised corvettes to be complemented by 18 new fast attack craft. Also also, the fleet's existing 6 Type 212 A air-independent attack submarines will be replaced with 6-9 boats of the larger Type 212 CD class as well as 6 large unmanned underwater vehicles. (Source, German)