Lucent Technologies Inc.

Other

Agere Systems Inc.

Agere Systems Guardian Corp.

David Esley Long

Sharad Kapur

Peter Feldmann

Robert C Melville

Jingsong Zhao

Jaijeet S Roychowdhury

Venugopal Gopinathan

Peter R Kinget

Significant improvement is achieved in the analysis of IC layout by utilizing the fact that IC designs exhibit a large amount of regularity. By employing a unique mesh generation approach that takes advantage of the regularity, combined with the use of a limited number of different shapes for the majority of the IC geometry greatly increases the speed of processing. Additionally, by employing a unique approach for specifying the different mesh elements&#x2014;based on the parameters that define the relative difference between one shape and another&#x2014;provides significant additional reductions in the necessary calculations, and a corresponding increase in speed of IC simulations. Yet another improvement is realized by simplifying the inductive influence calculations by employing averages that permit using dot products of vectors rather than integrations of non-constant vectors.

Efficient large-scale full-wave simulation

For use in an integral equation formulation of capacitance, a system for, and method of, generating a representation of charge distribution for a given capacitive structure (which may be an integrated circuit). In one embodiment, the system includes: (1) a charge variation function generator that creates a multidimensional charge variation function that is not directly dependent on a conductive geometry of the structure and (2) a conductive geometry generator, associated with the charge variation generator, that creates a conductive geometry that is independent of charge variation in the structure, the charge variation function and the conductive geometry employable in the integral equation formulation to reduce a complexity thereof.

System and method for determining capacitance for large-scale integrated circuits

Apparatus and method for simulating a component, where the component is conducting a current density, are disclosed. In one embodiment, the method includes discretizing the component into a plurality of triangular elements, and computing Green's functions descriptive of the relationship of the elements discretizing the component. In addition, the method includes computing basis functions relating to the elements, where the basis functions decompose the current density into divergence free and curl free parts, and the curl free parts are computed using a spanning tree. The method further includes combining the Green's functions and the basis functions to calculate a value representing a current density of said component. In one embodiment, the apparatus includes components configured to discretize the components, process Green's functions, compute basis functions, and combine the Green's functions and the basis functions to arrive at the value.

Efficient electromagnetic full-wave simulation in layered semiconductor media

Quadrature solutions for 3D capacitance extraction

A method for improved memory management during the processing of binary decision diagrams in a computer system. Prior to creating a new node in memory, a find operation is performed to determine if that node already exists in memory. A hash key is computed for the new node and a hash table is accessed to retrieve a pointer to a linked list of nodes which are potential matches for the new node. The linked list is in increasing order of the chronological age of the nodes. The nodes are sequentially retrieved from main memory in the order of the linked list. The retrieval is terminated at the last linked node which was created subsequent to the child nodes of the new node.

Memory management during processing of binary decision diagrams in a computer system

Two or more equal amplitude periodic output signals which are mutually shifted in phase by an integer fraction of 360 degrees, such as 90&deg;, are generated by injection locking a ring type oscillator circuit arrangement with a periodic low phase noise signal source. More particularly, a first ring oscillator is injection locked by a low phase noise signal source, one having a noise characteristic which meets the GSM radio standard of at least &minus;132 dBc/Hz at a 3 MHz offset. An identical second ring oscillator is then driven with the output of the first ring oscillator. In one circuit configuration, an even numbered, e.g., a four stage ring oscillator is injection locked to a low-phase noise oscillator having a predetermined noise specification which is application specific and wherein a second even numbered stage, e.g., a four stage ring oscillator is coupled to the first ring oscillator. In a second circuit configuration, a first odd numbered, e.g., three stage ring oscillator, is injection locked to a low phase-noise oscillator and a second odd numbered, e.g., three stage ring oscillator, is injection locked to the first ring oscillator.

Injection locked multi-phase signal generator

Methods and apparatus for performing non-linear analysis using preconditioners to reduce the computation and storage requirements associated with processing a system of equations. A circuit, system or other device to be analyzed includes n unknown waveforms, each characterized by N coefficients in the system of equations. A Jacobian matrix representative of the system of equations is generated. The Jacobian matrix may be in the form of an n&times;n sparse matrix of dense N&times;N blocks, such that each block is of size N,. In an illustrative embodiment, a low displacement rank preconditioner is applied to the Jacobian matrix in order to provide a preconditioned linear system. The preconditioner may be in the form of an n&times;n sparse matrix which includes compressed blocks which can be represented by substantially less than N,elements. For example, the compressed blocks may each be in the form of a low displacement rank matrix corresponding to a product of two generator matrices having dimension N&times;&agr;, where &agr;<<N. The preconditioned linear system may be solved by factoring the preconditioner using a sparse lower-upper (LU) factorization or other similar sparse factorization method applied to the compressed blocks.

Low-displacement rank preconditioners for simplified non-linear analysis of circuits and other devices

A frequency-domain analysis method computes noise power spectral densities (PSDs) in nonlinear circuits. The method uses harmonic components of the periodic time-varying PSD of cyclostationary noise, i.e., harmonic power spectral densities which are deterministic functions that describe the time-varying second-order statistics of cyclostationary noise. A block-structured matrix equation is used which relates output noise statistics to input noise statistics. By exploiting Toeplitz block structure, an efficient noise calculation method requires O(nN log N) computation time and O(nN) memory, where n is the circuit size and N is the number of significant harmonics in the circuit's steady state. The method successfully treats device noise sources with arbitrarily shaped PSDs (including thermal, shot, and flicker noises), handles noise input correlations and computes correlations between different outputs.

Method of making an integrated circuit including noise modeling and

A component design tool extracts a parameter associated with a component defined in a model of a physical system. The design tool discretizes the component and generates a matrix representative of a specified parameter. By subdividing the matrix into a hierarchy of submatrices and iteratively compressing and blending the submatrices, the design tool produces a compressed matrix. The compressed matrix is efficiently solved using iterative techniques. From the solution of the matrix, the design tool calculates the specified parameter.

Method and apparatus for designing interconnections and passive

A layered structure is divided into a plurality of regions. Transmission line equivalents (Green's functions) in the spectral domain are formed between all regions within the layered structure. The spectral domain Greens' function are converted to the spatial domain using a near field and a far field computed for those regions part of a component within the layered structure. The far field is extracted from a compressed database computed from the transmission line equivalents and descriptive of the layered structure. The near field is computed using a prioritization mechanism. Priority is assigned in accordance with the amplitude of a source and the length of the path between regions of interest. Once the physical characteristics of the layers used in the fabrication process of the IC are identified, the database used for computation of the far field is compiled and compressed, and remains unchanged for each new parameter extraction. Thus, compressed, layered Green's functions in the database decouple the computation of the far field from the layer structure and circuit geometry, minimizing computation time.

Efficient three dimensional extraction

Methods and apparatus for performing frequency domain analysis using compressed matrix storage to reduce the computation and storage requirements associated with processing a system of harmonic balance equations. A nonlinear circuit, system or other device to be analyzed includes n unknown node spectra, each characterized by N spectral coefficients in the system of harmonic balance equations. A compressed version of a Jacobian matrix J representing the system of harmonic balance equations is generated by forming m sequences of length N using one or more block-diagonal matrices associated with the Jacobian matrix J, converting each of the m sequences to the frequency domain using a discrete Fourier transform, such that a set of Fourier coefficients are generated for each of the m sequences, and storing only those Fourier coefficients which exceed a threshold as the compressed version of the Jacobian matrix J. Information generated from an inverse transform of the compressed version is utilized to solve a preconditioned linear system J.sup.-1 JZ=J.sup.-1 W which is based on an approximation J of the Jacobian matrix J.

Efficient frequency domain analysis of large nonlinear analog circuits

A high altitude reconnaissance platform is implemented by an ultralight aircraft powered solely by long wave infrared cells mounted on the lower surfaces of the wings and the fuselage. The aircraft may be of the pusher, slow speed propeller style, with a larger rear wing and a small, canard-type front wing. The bottom of the fuselage may be flat. The two wings may be vertically offset from one-another, and the cross-section of the wings may be relatively thick, with the ratio of the width of the wings to their thickness being in the order of about 6 to 8.

Infrared radiation powered lightweight aircraft

A high altitude, ultra lightweight aircraft has broad area relatively flat wings, and is provided with solar cells on its upper wing surfaces, and long wavelength, infrared responsive cells on its lower wing and fuselage surfaces, to provide enough power to maintain the aircraft aloft at high altitudes indefinitely. The aircraft is intended to fly at altitudes of about 60,000 feet to 110,000 feet, at speeds in the vicinity of 70 to 200 miles per hour. A battery or fuel cell and electrical system is provided to store excess electrical power and to supply electrical power when needed. A large, low speed, pusher propellor is driven by an electrical motor. The aircraft may be launched with an opaque balloon, which not only raises the aircraft to the desired elevation but also conceals it.

Growing community of inventors

Union County, NJ, United States of America

David Esley Long