0 pins are on the high power RF circuit board.Input RF type Amplifier, Mixer of the Evaluation board.Using the HMC8108 search parameter, you can discover variants of the RF Board.
EV1HMC8108LC5 Features
0 pins Amplifier, Mixer Type
EV1HMC8108LC5 Applications
There are a lot of Analog Devices Inc. EV1HMC8108LC5 RF Boards applications.