Yves Quere

Analytical Expressions for Capacitive and Inductive Coupling

In this paper, a new crosstalk RLC noise expression is proposed, based on an RLC transmission line model associated to each propagation mode, which is capable of predicting the noise amplitude and the noise pulsewidth of an RLC interconnect. Several simulations reveal that the proposed expression predicts the peak crosstalk noise and the pulsewidth with a good level of accuracy. This simplified analytical expression of crosstalk noise is sufficiently accurate to be effectively incorporated in noise calculators state-of-the-art

Return path assumption validation for inductance modeling in digital design

Inductance modeling for on-chip interconnects in a typical digital environment is proposed. Regarding the effective loop inductance computation, the issue of current return path assumptions is first discussed. Then, sensible assumptions about the return path localization are presented and systematically validated. Finally, representative structure models allowing prelayout effective inductance estimations are suggested.

A global synthesis tool and procedure for filter-antenna co-design

This paper presents a novel method for co-designing filters and antennas. Commonly, the filter and the antenna are separately designed, which usually induces reduced performances in terms of energy efficiency (due to losses) and dimensions. We propose first to model the antenna as the last low to medium Q-factor filter resonator. Then, the synthesis is performed considering this particular resonant load. Finally, an automatic synthesis, based upon a Matlab™-HFSS™ coupling analysis is developed leading to a direct extraction of the filter-antenna layout for EM analysis and implementation. The proposed synthesis technique and the associated software interface offer new degrees of freedom in the design procedure, enhancing the performances of the whole sub-system.

High-Frequency Effects of Orthogonal Interconnect Layers on Inductance in High-Speed VLSI Circuits

This communication deals with frequency behavior of orthogonal interconnect layers on inductance in high-speed VLSI circuits. The RLC parameters of the distributed model are determined by electromagnetic simulations. We evidence the error made on inductance in the range 1-50 GHz for three traditional interconnect configurations. A time-domain analysis highlights the impact of the inductance error on digital signals propagation. This analysis uses a numerical tool to take into account the frequency dependence of RLC parameters

3D frequency-dependent RLC elements extraction by full wave analysis: identification of the return current paths in complex power and ground grids of high speed VLSI circuits

This communication deals with the extraction and simulation of on-chip RLC per unit length (p.u.l.) elements for an efficient analysis of high speed digital circuits. In this context, the current distribution in the whole circuit, power and ground grids included, has to be known to correctly estimate inductance. By using a 3D full-wave finite elements method, we identified the current paths arising in the power and ground grids when an on-chip signal switches on a wire placed in a metal below the grids.

Design and manufacturing of a 3-D conformal slotted waveguide antenna array in Ku-band based on Direct Metal Laser Sintering

One of the growing trend in antennas is to address multifunctional systems, providing direct space saving and cost reduction. A consideration for future generation antennas is to replace the classical planar geometry with new functionalities. Three-dimensional (3-D) / conformal antennas offer significant advantages for such system. However, traditional manufacturing processes limit their realization. Additive Manufacturing have been identified as very promising solutions to overcome the dimensional challenge that 3-D components represent. These technologies enable the manufacturing of complex and conformal structures and goes beyond the conventional subtractive manufacturing techniques. In this contribution we propose to evaluate the manufacturing capacities of the Direct Metal Laser Sintering (DMLS). For this purpose, we need an easy-to-test antenna structure containing pertinent features representative of all complication we can run into when designing a complex antenna, including phased array antenna. We propose a conformal slotted waveguide antenna arrays (SWAA) operating in Ku band. The electrical performances of the device have been compared between simulation with ANSYS® HFSS™ software and measurements. Despite a mismatch in the reflection parameter, good results are obtained in gain. They enable us to envision promising future achievements and a better mastering of the global set of parameters.

Return Path Assumption Validation for Inductance Modeling in Digital Design

Inductance modeling for on-chip interconnects in a typical digital environment is proposed. Regarding the effective loop inductance computation, the issue of current return path assumptions is first discussed. Then, sensible assumptions about the return path localization are presented and systematically validated. Finally, representative structure models allowing prelayout effective inductance estimations are suggested.

A numerical method for a full-wave electromagnetic analysis of systems on chip

In the context of RF and high-speed circuits, Systems On Chip with Analog and Mixed Signals (SOC-AMS), interconnect has becoming a dominant factor in determining circuit performance and reliability in deep submicron designs. Transmission line properties of on-chip wiring need to be taken into account due to the great lengths and fast rise times encountered. Coupling noise between adjacent interconnects can also cause catastrophic effects on the logical functionality and long-term reliability of a VLSI circuit. With these trends, the electrical phenomena that have to be investigated are governed by the electromagnetic theory. However, its impossible to proceed to a complete SOC - AMS analysis with a full wave electromagnetic numerical tool, due to the large scale integration. As interconnects are typically of very large size and high-order, model-order reduction becomes necessary for efficient SOC modeling, simulation, design and optimization. In this communication, a new method based on numerical inversion of Laplace transform and on a discrete model-reduction technique is presented for simulating peak crosstalk noise problems found in high speed digital circuits and SOC-AMS. The method, particularly efficient and easy to be implemented in a program, is useful for an electromagnetic simulation of a complete system.

A novel approach to co-design microwave devices with distributed switches

This paper deals with a novel approach to co-design a microstrip line associated with a distributed PIN switch in a semiconductor substrate. An High-Resistivity Silicon (HR-Si) substrate was chosen to optimize the trade-off between semiconductor effects and microwave propagation. Indeed, thanks to this particular substrate, the novel co-design concept is illustrated by an integrated and distributed switch based on an N+PP+ junction. This concept offers great flexibility in the design of tunable microwave devices. Moreover, applied to tunable distributed systems (antennas, filters, etc) in planar technology, it makes it possible to avoid the need for reported components or metalized holes. The coupling between semiconductors and microwave devices is taken into account thanks to a new co-design flow. Two demonstrators, with switchable doped microstrip lines, are manufactured and measured to validate the approach. The performances achieved in terms of insertion losses (IL) and isolation (Iso) were lower than 2.8 dB and higher than 40 dB, respectively, over the whole frequency band under consideration (from DC to 20 GHz).

Energy Recovery from Microstrip Passive Circuits

In this paper, the energy recovery in microstrip passive circuits from the power losses into heat is studied. For this purpose, a thermoelectric generator (TEG) based on the Seebeck effect principle is used, which converts part of the power dissipated into heat to dc electrical power. A solution integrating the TEG with the microstrip circuit is proposed, and design guidelines in order to optimize the recovered power keeping a good isolation between the RF signal and the TEG system are provided. As will be shown, under moderate applied signal powers of just 1–5 W, the levels of recovered power in microstrip passive circuits can be notable. As a demonstrator circuit, an integration device formed by an embedded microstrip bandpass filter for WiMAX applications and a TEG is designed, fabricated, and characterized (thermal and electrically). Different scenarios are considered, depending on frequency and thermal loads. For an applied inband CW input signal power of 2 W at 3.48 GHz, a recovered power of around