https://wccftech.com/snapdragon-888-galaxy-s21-smaller-mmwave-module/

During Samsung’s announcement of the Galaxy S21, Galaxy S21 Plus, and the Galaxy S21 Ultra, the company didn’t care to showcase how it partnered with Qualcomm not just for its Snapdragon 888 but for its smaller mmWave antenna modules. A recent teardown of the flagship showed that the innards are almost identical to those present in the Galaxy S20, but with a small change.

The first teardown of the flagship showed what appeared to be Qualcomm’s third-generation QTM535 mmWave antenna modules. Apparently, there are two of them, as you can see in the image below. Since they are compact in size, Samsung has room to place different components inside. Also, there are two mmWave antenna modules, most likely to improve mmWave 5G performance and signal reliability.