BUY MSA-0504 https://www.utsource.net/itm/p/503398.html
Cascadable Silicon Bipolar MMIC Amplifier
MSA-0504 is a SMT05 (Surface Mount Technology) connector manufactured by HP/Agilent. It is a 50-ohm, 4-pin connector designed for use in high-frequency applications. It is suitable for use in applications such as cellular base station antennas, wireless local area networks (WLANs), and other high-frequency applications. The connector features a low-profile design, high-frequency performance, and a wide range of mounting options. It is also RoHS compliant. (For reference only)