Jeremy Raoult

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.

Millimeter-wave near-field imaging with bow-tie antennas

A near-field reflectometry experiment operating at 60 GHz is built in view of material and circuit inspection. Experiments are always obtained in constant height mode of operation. The bow-tie near-field probe acts mostly as a linearly-polarized electric dipole and allows strongly subwavelength resolution of ≈ λ/130. Its interaction with sample is shown polarization dependent and sensitive to both the local topography and the local dielectric constant or metal conductivity. Resonant and non-resonant probes are both evaluated.

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.

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.

Modeling and Analysis of Large-Signal RFI Effects in MOS Transistors

The ability of radio-frequency (RF) interference signals to upset or disrupt electronic equipment is a matter of concern, and identification of the physical mechanisms leading to device malfunction is of prime importance. This paper presents experimental and theoretical results and analyzes the effects of a large-signal microwave excitation up to 2 GHz on several commercial small-signal MOS transistors. For frequencies beyond the maximum operating frequency, experimental results show RF signal rectification in the devices, and these results are confirmed by SPICE simulations using extracted models for the transistors, including package and test circuit parasitics, with excellent agreement with experiments. Analysis of internal transistors currents and voltages finally leads to the conclusion that the observed rectification effect is not due to active nonlinearities of the devices, but rather due to the nonlinear overlap and parasitic drain–bulk diode capacitances of the MOS transistors. In particular, the role of the nonlinear voltage dependence of the junction capacitance is highlighted. Finally, a simplified model is proposed to reproduce this behavior.

Control of a Mos Inverter by Out-of-Band Pulsed Microwave Excitation

An intentional focusing of High-Power Microwave (HPM) energy on microelectronic systems can produce effects that will potentially upset or damage the target. However, the physical mechanisms at work within the device are not often well understood. We provide a detailed understanding of the physical mechanisms involved in a common-source Metal Oxide Semiconductor (MOS) transistor inverter when Pulsed Microwave Excitation (PME) in a frequency range from 10 MHz to 1 GHz is applied on the gate terminal. Our study is based on the measurements of the current waveforms on all transistor access and explains the MOS response with and without the Radio-Frequency (RF) interference.

Remote Extinction of a 2.4 GHz RF Front-End Using Millimeter-Wave EMI in the Near-Field

The effects of highly out-of-band electromagnetic interference (EMI) on an RF front-end are experimentally evaluated. Irradiation at 60 GHz with a moderate power is produced in the near-field owing to an open-ended WR15 waveguide fed by a Gunn diode. Surprisingly, we easily obtain the remote extinction of either the transmitter or the receiver of the front-end subject to EMI. The paper proposes a detailed analysis of both CW and chopped EMI by varying almost all experimental conditions, namely the polarization, target distance, and chopping mode. The latter shows most efficiency and evidences some long time scale dynamics in the induced perturbation.

Optimization of Near-Field Image Capture With Millimeter-Wave Bow-Tie Probes

A 60 GHz high-spatial resolution millimeter nearfield scanning microwave microscope system is developed. Like in scanning near-field optical microscopy, it involves a modulation of the probe-sample distance. An analytical model of the near-field detection versus the minimum probe-sample distance is derived as a function of the harmonic rank used for lock-in detection. The model is validated owing to various probe sizes and materials. Both the model and experiments exhibit the filtering out of low spatial frequencies, the best efficiency being obtained at highest harmonics. It yields a resolution of ≈2 μm (i.e., λ/2500) with an 18 μm gap bow-tie probe and an optimized detection setup operating on the third harmonic.

RF Front-Ends Nonlinearity Characterization Using Reflected Power

The electromagnetic susceptibility to third-order intermodulation (IM3) of radio-frequency (RF) receiver front-ends is studied. Two-tone test is the most widely used nonlinear distortion characterization method. It produces IM components in operating bands of RF front-end, which are called in-band IM products and are caused by system nonlinearities. It is proposed here to measure the IM3 signal reflected by the system when two-tone excitation is applied to the antenna port. The method is shown to agree well with standard estimations of the nonlinear properties of various radio receiver front-ends with different designs. Devices are compared in terms of susceptibility to intermodulation.