The MMCX female connector used on Digi RF products (XStream and XCite) is an Amphenol part number: 908-22101
You can download datasheets and specifications here.
Click on "Customer Drawing" for a more detailed picture with measurements. The center conductor is female (jack).
Here is an alternate part from Connex.
The height of the female MMCX connector when connected to with a right-angle male connector (availabe from MaxStream on antennas or cables) is approximately 0.31 inches above the component side of the module PC board.
The expected loss for the MMCX connector is 0.3dB though we have measured losses as high as 1.3dB when connected. The RPSMA connector option has a consistent 0.3dB loss.
Last updated: Aug 08, 2017