I have an antenna line for a cell modem. The modem manufacturer specifies a particular PCB layer stack up, seemingly with the implication that following that stack-up is good enough. But the PCB manufacturer wants to know if the trace needs impedance control. I don't have the emag skills to know if such a short trace does indeed require impedance control?
I've attached a small image showing the connector and trace in question (near the center of the image, refdes S2/CONN2).