A DC-Return And also a Bias-Tee can't be built-in to the exact same output concurrently. On the other hand, if a Bias-Tee is currently there it could be converted to get a DC-Return, just by connecting the bias tee pin to ground by way of a 47 Ohm resistor (as https://rf.vllis.com/en/product-category/broadband-amplifiers