Does the edge box antenna layout affect radiated interference immunity?

The layout of the built-in 4G/5G WiFi antenna in the edge computing box has a decisive impact on its radiation immunity performance. When the antenna is close to internal interference sources such as DDR clocks, not only does its own signal-to-noise ratio deteriorate, but it also introduces spatial electromagnetic waves into the receiving link, causing communication interruptions. The optimization strategy is to keep the antenna away from the high-speed area of the motherboard by more than 20mm and place it at the corner of the PCB or on an independent antenna bracket. The antenna feed line must use coaxial cable shielding and be grounded at both ends 360°. The RF traces on the internal PCB must be grounded and connected in series with a PBZ1608E600Z0T ferrite bead near the antenna port to suppress common-mode current. The power supply feed is equipped with a common-mode inductor CML3225A-101T. The CML common-mode inductor 3225 is 3.2×2.5mm in size and 101T with an inductance of 100μH, which can prevent power supply noise from modulating the RF signal. At the same time, ESD protection such as ESDLC3V3D3B is added to the RF switch and LNA. Its low capacitance characteristics do not attenuate the RF performance. With the above layout, the edge box radiation immunity maintains more than 95% throughput at 10V/m.