How to control EMI in the wireless transmission of a power FTU?

EMI control for wireless long-distance transmission (4G/5G) requires protection against radio frequency interference circuitry. A combination of shielding and filtering is employed. The wireless module is fitted with a 0.8mm thick metal shield with an opening size less than λ/20 (7.5mm at 2GHz). The module power line is connected in series with a PBZ1608E600Z0T ferrite bead (600Ω@100MHz) and in parallel with a 10μF + 100nF capacitor. The antenna feed uses a coaxial cable with an outer shield grounded. PCB design: RF traces are controlled with 50Ω impedance and kept away from sensitive circuits. The module is connected to the motherboard via an ADUM1410 serial isolator. Through this control, the wireless module's radiated emissions meet EN55032 Class B, while its immunity passes the IEC 61000-4-3 10V/m test.