How to suppress interference in the wireless module of the intelligent controller PAC?

To suppress interference from wireless modules (such as Wi-Fi, Bluetooth, and 4G) in a smart controller (PAC), isolation, filtering, and frequency band management are necessary. The wireless module should be placed in a separate area on the PCB, isolated by grounded copper strips, and shielded if necessary (with openings smaller than λ/20). The module power supply should use an LDO (such as a low-dropout regulator) instead of a switching regulator, with a ferrite bead (PBZ1608A-102Z0T) connected in series and a 0.1μF capacitor in parallel for filtering at the input. The antenna feed line should use 50Ω impedance matching and be kept away from digital circuits and power lines. The area around the antenna should be clear, and all layers below it should be cleared. For multi-band modules, a bandpass filter (such as a SAW filter) should be used to remove out-of-band noise. Simultaneously, the timing of wireless communication and high-speed digital operation should be staggered in the software. Tests show that this suppression scheme can improve the wireless module's receiver sensitivity by 3dB, reduce its radiated emissions by 10dB, and pass the IEC61000-4-3 radiated immunity test.