0 pins are on the high power RF circuit board.Input RF type Switch, SPDT of the Evaluation board.Using the HMC349 search parameter, you can discover variants of the RF Board.PCB is the one that mounts RF Board.
EV1HMC349AMS8G Features
0 pins Switch, SPDT Type
EV1HMC349AMS8G Applications
There are a lot of Analog Devices Inc. EV1HMC349AMS8G RF Boards applications.