Analysis Of High-speed Interconnects Research Articles

Signal Integrity Analysis of High Speed Interconnects In PCB Embedded with EBG Structures

This paper brings out a novel method for reducing Near end and Far end Crosstalk using Electromagnetic Band Gap structures (EBG) in High Speed RF transmission lines. This work becomes useful in high speed closely spaced Printed Circuit Board (PCB) traces connected to multi core processors. By using this method, reduction of -40㏈ in Near-End Crosstalk (NEXT) and -60 ㏈ in Far End Crosstalk (FEXT) is achieved. The results are validated through experimental measurements. Time domain analysis is performed to validate the signal integrity property of coupled transmission lines.

Finite-Difference Analysis of Interconnects With Frequency-Dependent Parameters Based on Equivalent Circuit Models

A new method for finite-difference analysis of high-speed interconnects with frequency-dependent parameters is presented. A set of differential equations are derived based on the equivalent circuit models of dispersive transmission lines. The finite-difference time-domain (FDTD) method is then employed to solve them involving no convolution computations. The proposed method has the identical memory requirement and computational expense as the recursive-convolution-based algorithm, while more accurate results are obtained. The generalized two-port equivalent model of transmission lines contributes to the convenience of dealing with arbitrary termination networks. In addition, a higher order (2,4) FDTD scheme is employed to improve the accuracy and efficiency of this algorithm. The validity and accuracy of the proposed method are illustrated by several numerical examples.

Analytical Model for Optimum Signal Integrity in PCB Interconnects Using Ground Tracks

In this paper, we present analytical models for line impedance and the coupling coefficient in the presence of additional ground tracks. We use a variational analysis combined with the transverse transmission-line technique to model interconnect lines guarded by ground tracks. Using the proposed model, it would be possible for designers to reduce crosstalk in coupled lines and obtain desired line impedance, thereby ensuring optimum signal integrity. The results obtained are verified by full-wave simulations and measurements performed on a vector network analyzer. The proposed model may find applications in the design and analysis of high-speed interconnects.

Analysis of high-speed interconnects using efficient multipoint Padé approximation

An efficient method is presented for analysis of large interconnect circuits including lossy coupled transmission lines. Based on multipoint Padé approximations and a new expansion point search algorithm, the method can obtain single close-form frequency-domain and transient solutions of the interconnect problem with a minimum of frequency expansion points.

Analysis of high-speed interconnects in the presence of electromagnetic interference

This paper describes an efficient algorithm based on moment-matching techniques for simulation of high-speed circuits in the presence of electromagnetic interference (EMI). The proposed method is based on the recently developed complex frequency hopping (CFH) technique for interconnect analysis. The new technique is useful for susceptibility analysis and is two to three orders of magnitude faster than conventional simulation techniques. In addition, it can be extended to the analysis of interconnects with frequency-dependent parameters and nonlinear terminations.

Recursive algorithm for transient analysis of lossy transmission line

A recursive algorithm is presented for the time-domain simulation of lossy transmission lines. It can be used efficiently for the transient analysis of high speed interconnects in high-speed VLSI circuits and multichip modules (MCMs).

Full-wave analysis of high-speed interconnects using complex frequency hopping

Accurate simulation of large interconnect networks has become a necessity to address signal-integrity issues in current high-speed very-large-scale-integration designs. To accurately characterize a dispersive system of interconnects at higher frequencies, a full-wave analysis is required. However, conventional circuit simulation of interconnects with full-wave models is extremely CPU expensive. Recently published moment-matching techniques provide a generalized approach to lumped/distributed circuit response approximations. However, these techniques are based on quasi-transverse electromagnetic mode (TEM) assumption and have no mechanism to handle full-wave models. In this paper, we present a new method to extend model-reduction techniques for simulation of full-wave models. The following three new results are presented in this paper: 1) a generalized method to combine modal results from a full-wave analysis into circuit simulators; 2) a new algorithm for moment generation involving full-wave models; 3) deviations associated with quasi-TEM approximations compared to full-wave models at higher frequencies. The proposed algorithm yields a speed up of 1 to 2 orders of magnitude for a comparable accuracy with conventional techniques. In addition, the proposed method can be used for a mixed simulation involving distributed models with frequency dependent/independent RLCG parameters, full-wave interconnect models and measured subnetworks along with nonlinear terminations.