CRC9 to SMA Female patch cables are designed to connect a feeder or jumper cable to a user device such as a mobile broadband modem.
The cable's CRC9 connector matches the external antenna connection on many 4G modems. Brands such as Huawei and ZTE use the CRC9 connection to allow the attachment of larger 4G antennas. 4G modems generally use two CRC9 connectors to attach 2x2 MIMO external antennas.
This patch lead is 18 cm (180 mm) in length, and uses a high quality L-100 coaxial cable. With the advancement of 4G and 5G into higher frequency bands conventional RG-174 and RG-316 can no longer be used.
Externally mounted antennas improve the performance of mobile broadband by receiving the stronger signal naturally present outside the building. CRC9 is a compact, low cost RF interface capable of handling frequencies through to 3 GHz, making it suitable for 3G and 4G frequencies.
It's important to point out that many 4G and 5G modems are no longer using external antenna connectors. Technology has evolved to require larger numbers of antennas and operate at frequencies that the CRC9 cannot handle.