Sylvie Jarrix

Near-Field Electromagnetic Characterization and Perturbation of Logic Circuits

We propose here a nondestructive electromagnetic (EM) near-field test bench for both EM compatibility and susceptibility of circuits. This setup permits both the collection of the near field and injection without contact of a disturbing EM field, all through a probe. Exhaustive characterizations of probes are undertaken via simulations and experiments. According to their design, they are supposedly linked more to the electric or the magnetic field. Simulations of their EM behavior are undergone to fix their optimal geometries, leading to the best measurement performances. It is shown by both the simulations and the S-parameter measurements that their presence does not interfere with the electric behavior of the device under test. Then, logic circuits are characterized from the EM point of view, with the help of this test bench. Circuits are placed on three different printed boards: one double-sided low-frequency board without a ground plane and two single-sided boards with a ground plane and a design that is more or less optimized. EM near-field mappings highlight the strong field areas of the circuits. The need for a ground plane is highlighted. Field patterns on the traces are linked with those observed on microstrip lines. Then, an EM aggression is injected over a supposed sensitive zone of the circuit. Whichever printed board is considered, a parasitic signal superimposes itself on the output signal of the gates. Deepened studies are undergone to exhaustively explain the phenomena observed.

Probe Characterization for Electromagnetic Near-Field Studies

Probes used for contactless electromagnetic field capture or injection are characterized. Depending on the probe structure, they interact preferentially with the electric or magnetic field. The optimal size of the probes for broad-frequency-band measurements is investigated. However, it is shown particularly for the magnetic field probe that considerations about the size and the structures presented in this paper are not sufficient for a good discrimination between electric and magnetic fields. Then, the space resolution of near-field measurements is discussed, with application to the field capture of a microstrip line under operation.

Effect of Low and High Power Continuous Wave Electromagnetic Interference on a Microwave Oscillator System: From VCO to PLL to QPSK Receiver

This paper presents the effects of a continuous wave electromagnetic interference (EMI) on a discrete microwave phase-locked loop (PLL). Susceptibility of the voltage-controlled oscillator (VCO) is first studied as a standalone circuit before being integrated into the PLL. The effects observed on the VCO alone and when it is integrated into the PLL are analyzed as a function of the frequency and power of the interference signal. Most of the effects observed are due to intrinsic nonlinearities of the VCO. Some of them, like intermodulation and injection pulling can be predicted by the small-signal perturbation theory, while others such as a phase unlocking condition generated by strong EMI injection cannot. Finally, the consequence of using such an EMI affected PLL used as a local oscillator in a QPSK receiver, is examined. In all cases, the EMI is injected at the output of the VCO through inductive coupling.

Interference Signal Effects on a High-Frequency Monolithic Voltage-Controlled Oscillator: Experiments and Simulations

This paper reflects a part of electromagnetic susceptibility studies conducted on active circuits. An electromagnetic interference (EMI) is injected on a 5 GHz monolithic voltage-controlled oscillator (VCO). This circuit is implemented on a 0.35 μm BiCMOS SiGe process. Injection locking and pulling are put in evidence when the circuit is subject to a high frequency interference with possible frequency band widened with respect to the oscillation frequency band of the VCO. A simulation process based on envelope-transient method is presented. Its main goal is to predict the behavior of the VCO under injection with interference signal power ranging from low to high level.

Electromagnetic analysis, deciphering and reverse engineering of integrated circuits (E-MATA HARI)

Electromagnetic fault injections are produced on secured ICs aiming to break crypto codes. We describe in this paper the whole chain of optimization necessary to achieve this goal, namely 1/ physical optimization of near-field probe and setup, 2/ signal management in timing, shape, and localization to induce the fault while beating countermeasures and 3/ understanding of fault propagation in logic to eventually protect future ICs.

Optimal Electric Wave Propagation Parameters on a Transmission Line - Schottky Diode System

This paper explores the optimal conditions for wave propagation on a microstrip line loaded by a Schottky diode. Investigations are undertaken by studying the transmitted power versus frequency, power and place of injection of a continuous sine high frequency aggression signal. The aggression is injected in a near- fleld mode. Coupling conditions between the aggression signal in the 500MHz{3GHz frequency band and the system is thus determined.

60 GHz active microscopy with a bow-tie antenna as near-field probe

A near-field reflectometry experiment operating at 60 GHz is built in view of material and circuit inspection. The linearly-polarized electric-field probe is a bow-tie antenna obtained from femtosecond laser cutting of pieces in a tungsten metal sheet subsequently attached to an open rectangular waveguide. First images reveal a true near-field detection with strongly subwavelength resolution up to λ/130 at a 5 μm probe-sample distance. Images of various metal objects evaporated on Si substrate also show near-field intensities that are quantitatively related to the conductivity of the different metals.