Phase Resolved near Field Dipole Reconstruction for Multilayer Board Far Field Escape Prediction
Phase-resolved near-field dipole reconstruction predicts far-field escape emissions within 2 dB, eliminating un-phased scan errors before SAC testing.
Far Field Escape Prediction
Radiated Estimation
Analytical equations project the strength of electromagnetic radiation from the vicinity of a printed circuit board to large distances. Far field escape prediction calculates the amount of electromagnetic energy that leaves the board and reaches the far field, where it can interfere with other electronic systems. This prediction is utilized in the early design phase to assess whether the layout will pass standard radiation compliance tests.
The applicability of this prediction is limited to distances much greater than the physical size of the board and the wavelength of the emitted signal.
Compliance Engineering
Design checks for electromagnetic compatibility utilize these analytical projections to identify layout flaws before manufacturing begins. When high-speed digital traces run close to the edge of a printed circuit board, far field escape prediction estimates the radiation escaping from the board edge and routing cables. This estimation guides the placement of decoupling capacitors and the routing of guard traces to minimize escape paths.
The simulation saves the cost of multiple board spins, though it cannot account for unpredictable routing of external system cables during final assembly.
Shielding Evaluation
Testing the shielding effectiveness of enclosure prototypes verifies the pre-manufacture radiation estimates. If the predicted escape value is high, designers must implement metal shields or conductive gaskets. This step guarantees that the final product meets the required international emission limits.