Search

We compute power-voltage, power-current, and causal definitions of the characteristic impedance of microstrip and coplanar-waveguide transmission lines on insulating and conducting silicon substrates, and compare to measurement.

In this work, we investigate the electrical performance of critical signal paths in IBM's S/390 MCM packages. We present lumped RLC-models suitable for standard circuit simulators like e.g. SPICE. The models are developed from finite element simulations of typical signal path segments. By comparing S-parameters from simulations of the models to two-port network analyzer measurements we validate the models in a frequency range up to 3 GHz.

This paper examines error caused by parasitic inductance in the characteristic impedance measured by the calibration comparison method on lossy silicon substrates.

We examine a broadband method to extract the dielectric constant and loss tangent of low-loss substrate materials from on-wafer scattering-parameter measurements of coplanar waveguides of different lengths. We compare against multiple-frequency measurements performed with a commercially available split-cylinder resonator and show good agreement over a broad frequency range for AF45 and alumina substrates.

We investigate the effect of uncertainties in the cross- sectional parameters of ungrounded coplanar waveguides (CPWs) on the characteristic impedance and the propagation constant. For our calculations, a quasi-TEM model is used that takes into consideration the effects of non-ideal conductors, substrate loss and finite metallization thickness. The propagation of uncertainties is studied with the aid of Monte Carlo (MC) simulations. The effect of different manufacturing technologies is exemplified by two typical microwave substrates (AF45 and AI2O3). Furthermore, the impact of the uncertainties in the input quantities is investigated in such a way that conclusions for the design of CPWs as well as for the requirements on the accuracy of material measurement methods can be drawn.

In this paper we present a CMOS compatible process for CMOS-grade wafers in order to create specific areas where radio frequency (RF) devices can be implemented without the high losses associated to this substrate. The process is based on refilling of deep trenches, which allows the local replacement of the silicon substrate by silicon nitride, which has very good RF properties (tan /spl delta/ = 5-9 10/sup -4/). The trenches are in the order of 30 /spl mu/m deep and 2 /spl mu/m wide, leaving a space of 2 /spl mu/m in between where the silicon still remains. In this way, half of the lossy substrate is replaced by silicon nitride. We present measurement results which indicate that the RF performance of CMOS-grade wafers can be significantly improved, as well as a careful study of the most relevant fabrication parameters and the consequences for the final RF performance of the substrate. An additional advantage of this new technique is the possibility of using it as a pre-CMOS process, thus allowing monolithic integration of CMOS electronics and RF and microwave components.

In this work, we investigate the electrical performance of critical signal paths in IBM S/390 MCM packages. We present lumped RLC-models suitable for standard circuit simulators operating in the time domain, e.g. SPICE. The models are developed from finite element simulations of typical signal path segments. By comparing S-parameters from simulations of the models to two-port network analyzer measurements, we validate the models in a frequency range up to 3 GHz.

We use a measurement method designed for coupled lines on highly conductive substrates to characterize identical asymmetric coupled lines fabricated on lossy silicon with and without a metallization plane beneath the two signal conductors. The study illustrates the important role of the return path in determining the electromagnetic coupling between the lines.

In this paper, we apply a measurement method designed for asymmetric coupled lines to determine the broadband propagation characteristics of symmetric coupled lines fabricated on a highly conductive silicon substrate. We show that the matrices of frequency-dependent propagation constants and characteristic impedances, as extracted from calibrated four-port S-parameter measurements, agree very well with data predicted by numerical calculations.

This paper examines a new method that accurately determines the characteristic impedance of planar transmission lines printed on lossy dielectrics, even when contact-pad capacitance and conductance are large. We demonstrate the method on a coplanar waveguide fabricated on fused silica and a microstrip line fabricated on a highly conductive silicon substrate.

We consider the problem of the identification of describing functions for the reduced time domain modeling of interconnects. In particular we identify the rational approximation of regular parts, once delays are exactly extracted, with a combination of vector fitting algorithm with a post-processing procedure based on a non linear least square refinement step. This improves the accuracy of the approximation obtained, and leads directly to rank-1 residue matrices. The technique is applied to a couple of test cases and a comparative evaluation of performances is carried out.