The reduction of electromagnetic radiation and couplings is a fundamental issue for electromagnetic compatibility (EMC) and electromagnetic interference (EMI) issues. Even though they represent distributed sources, radiation physics was seldom mapped to the geometry of the structure. In this paper, we develop a new approach based on PEEC to calculate the distributed sources for radiation and the couplings. With this approach, the radiated power from each segment as well as the transferred power between each part is evaluated. Furthermore, the physical meaning of the resultant power is interpreted. It is known that currents curved structures, bents, and other discontinuous and truncated structures cause significant radiation. The radiation from each part can be quantitatively analyzed. This method can be used to physically interpret and predict which features and structures have a small or a large impact on radiation. This provides powerful insight for diagnosing of radiation and couplings. Hence, this can be an important tool for product optimization's for EMI designs.