0 pins are on the high power RF circuit board.Input RF type Mixer of the Evaluation board.Using the HMC219 search parameter, you can discover variants of the RF Board.
EV1HMC219BMS8G Features
0 pins Mixer Type
EV1HMC219BMS8G Applications
There are a lot of Analog Devices Inc. EV1HMC219BMS8G RF Boards applications.