What does the ASDE-X ground radar unit look like?
This page claims to show the Raetheon ASDE antenna at Boston Logan. However, Saab Sensis appears to be the prime contractor for the ASDE-X system. Boston does have an ASDE-X system, according to the FAA. 



According to the above link, Saab provides the "Multi-Sensor Data Processor" that "fuses the surface movement radar, multilateration, ADS-B and terminal radar data into a single track that is correlated with flight plan information." So my guess is that Raetheon provides the radar antenna and Saab does the software integration, alerting, fusing, etc. Since the contract is in the US there may have been a requirement to use a US radar supplier. 

As an interesting aside, Saab recently announced a third generation Surface Movement Detection antenna, the SR-3: