Moncef Kadi

Characterization and Modeling of the Susceptibility of Integrated Circuits to Conducted Electromagnetic Disturbances Up to 1 GHz

This paper deals with the characterization, as well as the modeling, of the susceptibility of integrated circuits (ICs) to conducted electromagnetic disturbances such as a continuous-wave disturbance. Based on accurate measurement results, a robust mathematical model to predict the susceptibility of a CMOS inverter is developed. This model is based on a neural network approach and is validated up to 1 GHz for different test criteria. A good agreement between measurements and simulated results is reported. The mathematical model is implemented in a software tool such as Advanced Design System in order to facilitate its operation in the evaluation of the susceptibility of ICs.

A 3-D Near-Field Modeling Approach for Electromagnetic Interference Prediction

This paper presents, through an illustrative example, a 3-D modeling approach to predict the electromagnetic interference (EMI) between complex electronic devices and interconnections placed in the near-field region. Three different analytic coupling formulations have been investigated along with a 3-D-emission model to evaluate the induced voltages in transmission line (TL) extremities in the case of both matched and mismatched TL configurations. The proposed modeling method is successfully validated by comparison with numerical results using electromagnetic (EM) simulation tools and experimental results using near-field measurement. The obtained EM coupling results are more accurate than other traditional 2-D models.

A Novel Approach for Modeling Near-Field Coupling With PCB Traces

This paper presents a novel modeling approach for predicting the response of a printed circuit board (PCB) trace excited by a nonuniform electromagnetic (EM) radiated field from complex electronic components. The proposed approach is analytic and it is based on transmission line model with distributed sources taking into account the effect of the effective relative permittivity εreff of the PCB surrounding medium. The modeling procedure is a two-step approach: three-dimensional radiated emission modeling of the electronic component, source of EM disturbance, and using a set of equivalent sources followed by the computation of the induced voltages in the trace terminals referring to analytic coupling formulations. Comparison between modeled, numerical, and measured results enables us to validate the proposed model.

Modeling IC Snapback Characteristics Under Electrostatic Discharge Stress

This paper presents a novel technique for modeling the electrostatic discharge snapback phenomenon in integrated circuits (ICs). The macromodel is built using standard components: BSIM3v3.2 model for the MOSFET, a bipolar transistor modeled by Mextram 504.7, and a substrate resistor. The IC under test is characterized by its die and package impedance. The model should allow easier simulation program with IC emphasis implementation, high simulation speed, less convergence issues, and wider availability of a gate-grounded n-type MOSFET protection device. Our model determines the interaction between the protection device and the internal circuitry of the IC. The model parameters are extracted with MATLAB script. Simulation results are compared with transmission-line pulsing measurement for a voltage regulator NCV4949 and a controller area network transceiver TLE6250G.

Prediction of 3D-near field coupling between a toroïdal inductor and a transmission line

This paper presents an application of a 3D near-field modeling approach to predict the coupling between a toroïdal inductor (TI) and a transmission line (TL) placed in its vicinity. The TI equivalent 3D emission model is combined with analytic coupling formulations to compute the induced voltages in different configurations of the victim line. The proposed modeling procedure is less consuming in terms of computing times, preserves DUT confidentiality and offers an accurate electromagnetic interference (EMI) prediction. Results enable designers to optimize components positions inside electronic boards to guarantee electromagnetic compatibility (EMC) of the whole system.

Using neural networks for predicting the integrated circuits susceptibility to conducted electromagnetic disturbances

The decrease in normal signal levels, the increase in the operating frequencies, and the use of digital electronics in modern systems have led to the need for heightened EMC considerations, and consequently, better EMC models. A preliminary mathematical model based on neural networks theory is developed for predicting the level of susceptibility of integrated circuits to conducted electromagnetic disturbances such as a sine wave. A good correlation between measured and simulated results is obtained.

Estimation of the electromagnetic field radiated by a microwave circuit encapsulated in a rectangular cavity

A signal, propagating in an electronic circuit enclosed in a metal cavity, can excite the cavitys natural modes. In the context of RF amplifier reliability study against electromagnetic stress, a precise characterization of radiated emissions is imposed on us. This characterization is often achieved by measuring the near field of the circuit without enclosing it in a cavity (the top cover of the cavity is kept open), which does not always resemble the electromagnetic behavior when the same circuit is shielded within the cavity. In this work, we study the changes in the cartographies (electromagnetic fields mapping) of the electromagnetic field radiated under the influence of the metal cavity and we present a method to estimate the radiated field in the cavity from measurements made in the absence of the cavity. This method is validated for all frequencies except resonant frequencies.

Reliability of Radio Frequency Power Transistors to Electromagnetic and Thermal Stress

This chapter is focused on the study of the reliability of radio frequency (RF) power transistors used in high power amplifier (HPA) boards. These transistors constitute the central element of (Tx) transmission modules in radar applications. The behavior of RF transistors using gallium nitride (GaN) technology is tested by applying stresses caused by radiated electromagnetic waves, RF signals or thermal exposure. These stress tests lead to failure mechanisms representative of degradations observed in operation. The principle of this stress test approach is to aggravate these degradations by applying stresses that are representative of the harsh environments of RF power transistors.

Method of Characterizing the Electromagnetic Environment in Hyperfrequency Circuits Encapsulated within Metallic Cavities

Abstract: The designers of hyperfrequency modules accord particular importance to electromagnetic compatibility. To protect hyperfrequency power modules from external electromagnetic disturbances, such modules are enclosed inside metallic cavities. This prevents them from disturbing the neighboring circuits. In radar applications, power module output can exceed hundreds of kilowatts so their radiated emissions are very high. The harsh electromagnetism (EM) environment found in enclosed power modules can lead to failure mechanisms in the power transistors and impact on the reliability of radar systems. It is thus important to understand and control the EM environment of enclosed hyperfrequency power modules. In this chapter an innovative concept of determining the emissions radiated by the hyperfrequency structures found in metallic cavities is presented. This method is based on near-field measurements obtained from non-enclosed units and on radiated emission modeling by a network of dipoles.