Joint Tailoring of Electromagnetic Radiated Emission and Susceptibility Limits for Coexistence of Multiple Radio-Frequency Devices

The widespread deployment of multiple radio-frequency (RF) devices on complex platforms poses critical challenges for spectrum coexistence. Excessive radiated emissions and insufficient radiated susceptibility can cause intolerable interference, whereas traditional electromagnetic compatibility (EMC) design typically enforces uniform limits across all devices. Such uniformity neglects system heterogeneity, resulting in constraints with excessive interference margins or compromised system-level robustness. To address this issue, we propose a Joint Tailoring of Radiated Emission and Susceptibility Limits (JTRESL) framework. Explicitly accounting for the physical link between emission and immunity, a radiation coupling network model is first developed to characterize electromagnetic interference among devices. Based on this model, a multiobjective optimization formulation is established to balance interference immunity, implementation cost, and spectral smoothness, while incorporating engineering constraints. The resulting nonconvex problem is solved using an iterative algorithm based on sequential quadratic programming, which updates tailoring variables frequency-by-frequency and jointly optimizes emission limits and susceptibility thresholds. Experiments in a multidevice anechoic chamber demonstrate that the proposed method effectively eliminates interference states, controls engineering cost, and produces smooth limit curves. This enables targeted tightening in high-risk bands and appropriate relaxation in overly conservative bands. Overall, JTRESL provides an efficient and feasible solution to enhance EMC and spectrum coexistence in heterogeneous multiple RF platforms.