What is the recommended RF shielding approach for a multi-chip module with sensitive and noisy stages?

The recommended RF shielding approach for a multi-chip module (MCM) with sensitive and noisy stages uses internal compartmentalization to provide electromagnetic isolation between the sensitive receiver stages (LNA, mixer) and the noisy transmitter stages (PA, oscillator, digital control), preventing coupling that would degrade the receiver sensitivity and create spurious signals. The shielding architecture is: identify the isolation requirement (determine the required isolation between each pair of stages based on the signal levels and the acceptable interference: for example: a transmitter producing +30 dBm and a receiver with a minimum detectable signal of -100 dBm requires 130 dB of isolation to prevent the transmitter from desensitizing the receiver; the compartment shielding, combined with circuit isolation (filters, ground plane), must achieve this total), implement shielding compartments (divide the module PCB into compartments using internal shield walls (metal partitions) that extend from the PCB ground plane to the module lid; the shield walls are typically 0.5-1 mm thick CuBe, brass, or tin-plated steel; soldered to the PCB ground pads and making contact with the lid through EMI gaskets or direct metal-to-metal contact; each compartment should contain functionally related stages that do not require high isolation from each other), control the signal feed-throughs (every signal trace that crosses a compartment boundary creates a potential coupling path; feed-throughs between compartments should: be filtered (add an inline filter capacitor or pi-filter at the wall crossing point), pass through a cutoff opening (a slot in the wall that is below cutoff at the operating frequency), and be routed perpendicular to the wall (minimizing the slot radiation)), and seal the compartment seams (the junction between the compartment walls, PCB, and lid must maintain electrical continuity: solder the walls to the PCB ground plane (via a continuous row of ground vias along the wall footprint), use conductive gaskets between the wall tops and the lid, and ensure that no gaps larger than lambda/20 exist at the seams).