Pin descriptions in the datasheet @ HMC1040LP3CE, it say following,
Pin No:5-8, 14
The pins are not connected internally; however, all data shown herein was measured with these pins connected to RF/DC ground externally.
Do you recommend "the N/C pins connect to RF/DC ground externally" ?
Connecting the N/C pins to the ground might impact to thermal or electric performance ?
Thermal performance is more better, and electric performance is no impact ?