0 pins are on the high power RF circuit board.Input RF type Amplifier of the Evaluation board.Using the HMC754 search parameter, you can discover variants of the RF Board.PCB is the one that mounts RF Board.
126311-HMC754S8GE Features
0 pins Amplifier Type
126311-HMC754S8GE Applications
There are a lot of Analog Devices Inc. 126311-HMC754S8GE RF Boards applications.