An object oriented environment for modeling and synthesis of hardware circuits

Accurate performance modeling is essential for its usage in a circuit synthesis flow. Only a small fraction of the entire design space is occupied by designs with meaningful behavior and performance. In this work, we have focussed on modeling these feasible regions accurately in contrast with modeling the entire design space. Macromodels for the feasible regions were built hierarchically until the desired accuracy was achieved. An accuracy driven synthesis methodology is proposed to guide the identification of the feasible regions and dynamically enhance the performance of the macromodels. Dynamic performance modeling ensures true convergence of our synthesis approach as opposed to existing static macromodel based techniques. We applied the proposed methodology for modeling and synthesis of several analog and RF circuits and the results demonstrate that our approach yields highly accurate design solutions in a much smaller time compared to simulation based approaches.

A Group Contribution Method for Mineral Flotation Circuit Design

The development of practical methods for synthesis and verification of complex photonic circuits presents a grand challenge for the nascent field of quantum engineering. Of course, classical electrical engineering provides essential foundations and serves to illustrate the degree of sophistication that can be achieved in automated circuit design. In this paper, we explore the utility of term rewriting approaches to the transformation of quantum circuit models, specifically applying rewrite rules for both reduction/verification and robustness analysis of photonic circuits for autonomous quantum error correction. We outline a workflow for quantum photonic circuit analysis that leverages the Modelica framework for multidomain physical modeling, which parallels a previously described approach based on VHSIC Hardware Description Language (VHDL).

Reversible circuits are an emerging technology where all computations are performed in an invertible manner. Motivated by their promising applications, e.g. in the domain of quantum computation or in the low-power design, the synthesis of such circuits has been intensely studied. However, how to automatically realize reversible circuits with the minimal number of lines for large functions is an open research problem. In this paper, we propose a new synthesis approach which relies on concepts that are complementary to existing ones. While "conventional" function representations have been applied for synthesis so far (such as truth tables, ESOPs, BDDs), we exploit Quantum Multiple-valued Decision Diagrams (QMDDs) for this purpose. An algorithm is presented that performs transformations on this data-structure eventually leading to the desired circuit. Experimental results show the novelty of the proposed approach through enabling automatic synthesis of large reversible functions with the minimal number of circuit lines. Furthermore, the quantum cost of the resulting circuits is reduced by 50% on average compared to an existing state-of-the-art synthesis method.

An efficient approach for the synthesis of impedance matching circuits using arbitrary nonuniform transmission lines is proposed. The proposed technique is first summarized and its merits are discussed. Several practical examples are then considered and different matching circuits are synthesized covering wide impedance and frequency ranges. The results obtained by the proposed approach are compared to measured data as well as to those obtained by a commercial simulator using a full wave analysis.

The paper deals with synthesis of sequential circuits defined by their algorithmic state machine notation. Such circuits have a number of specific properties which enable efficient design of the circuits by utilizing so-called linearization techniques. A typical linearization technique includes calculation of autocorrelation values for a system of logic functions corresponding to the circuit. For the mentioned sequential circuits, the calculations which usually require massive computational recourses may be significantly reduced and thus low-overhead implementations of the circuits can be obtained relatively easy. The paper introduces a novel architecture of so-called linearized sequential circuits, and a piece-wise linearization approach for synthesis of sequential circuits. Results are evaluated both analytically and by using a number of standard benchmarks.

In control theory, models of physical processes, such as systems of differential equations, are usually checked against specifications, such as stability and set invariance. In formal methods, rich specifications, such as languages and formulae of temporal logics, are checked against models of software programs and digital circuits, such as finite transition graphs. With the development and integration of cyber physical and safety critical systems, there is an increasing need for computational tools for verification and control of complex systems from rich, temporal logic specifications. The formal verification and synthesis problems have been shown to be undecidable even for very simple classes of infinitespace continuous and hybrid systems. However, provably correct but conservative approaches, in which the satisfaction of a property by a dynamical system is implied by the satisfaction of the property by a finite over-approximation (abstraction) of the system, have received a lot of attention in recent years. Some classes of systems allowing for computationally efficient verification and control from temporal logic specifications are reviewed. For continuous and discrete-time linear systems and continuous-time multi-linear systems, it is shown that finite abstractions can be constructed through polyhedral operations only. By using techniques from model checking and automata games, this allows for verification and control from specifications given as Linear Temporal Logic (LTL) formulae over linear predicates in the state variables. A connection between the existence of Lyapunov functions and finite bisimulations is established for discrete-time linear and switched linear systems. Finally, optimality and correctness requirements are combined in a model predictive approach to generate control strategies for discrete-time linear systems. The usefulness of these computational tools is illustrated with various examples such as verification and synthesis of biological circuits in synthetic biology and motion planning and control in robotics.

The nullor, as a network element, is very popular in the areas of modeling, synthesis and analysis of analog circuits. Nullors are pathological or singular elements that posses ideal characteristics and are specified according to the constraints they impose on their terminal voltages and currents. Therefore, in order to compute symbolic expressions of pathological element-base equivalent analog circuits, the nullor properties should be taken into account in the formulation process. Nodal analysis (NA) of these circuits is very popular. However, the recently proposed methods of formulation the nodal admittance (NA) matrix, require many operations on the rows and columns of an initial node admittance matrix (INAM), which has the order (nxn), for the (n+1) node network or a laborious procedure of computation of norator and nullator indexes. This paper presents a new method of formulation of the nodal admittance matrix for linear active circuits with nullors that performs direct construction of the final nodal admittance matrix (FNAM), which has the order (n-k)x(n-k), and uses only classical methods of element stamps. (k is the number of nullators and norators pairs). The viability and the potentiality of the proposed method (of the FNAM) is showcased via application examples. The improved formulation method is compared with other formulation methods, showing that it is simpler.

This paper presents a novel filter-based analysis for the conventional rectangular patch antenna (RPA) using the Composite Right/Left-Handed Transmission Line (CRLH-TL) theory. We introduce two circuit models for RPA, described by lumped components and transmission line (TL) elements. An RPA is considered a Symmetric CRLH-TL (SCRLH-TL). We validated the analysis by comparing the circuit model and full-wave analysis simulation results. The TL circuit model error in the full-wave analysis was less than 5%. A dual-band Zeroth-Order Resonant (ZOR) antenna is designed and manufactured based on the introduced Lumped element circuit model, which exhibits filtering characteristics in both bands. We obtain the antenna circuit model by incorporating the RPA lump circuit model with LC resonators. We implemented the antenna structure by combining the RPA and complementary split-ring resonators (CSRR) modeled by the LC resonators. We initialized the antenna center frequency bands for WiMAX 2.45 GHz and 3.60 GHz. The CSRRs control the configuration of the center frequencies. The simulation and measured results are in good agreement. The proposed antenna dimensions are 0.66×\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ imes$$\\end{document}0.66×\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ imes$$\\end{document}0.012 λg\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\lambda _g$$\\end{document} at 2.45 GHz (43.22×\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ imes$$\\end{document}43.22×\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ imes$$\\end{document}0.81 mm3). The measured gains are 3.47 dB and 4.64 dB for 2.45 GHz and 3.60 GHz, respectively. Two radiation nulls were observed at 2.09 GHz and 2.98 GHz for the 2.45 GHz band and one radiation null at 3.45 GHz for the 3.60 GHz band. Also, the fractional bandwidth is 4.03% and 1.39%, respectively. The radiation pattern is nearly omnidirectional. The simulated efficiency is 90% for 2.45 GHz and 87% for 3.60 GHz frequency bands.

In this paper, a circuit synthesis approach based on an extended Foster canonical expansion for representation of distributed passive lossy electromagnetic structures is described. Compact lumped element model is extracted from data provided by numerical TLM method in the time-domain and then embedded into a conventional circuit simulator. The equivalent circuit synthesis procedure is applied to the two-port low-pass and band-pass microstrip filters. The resultant circuits with elements are analyzed and the obtained S parameters results are in a good agreement with numerical results.

In modern scenario as we are going for low power VLSI design, an useful technique is to design the combinational part of any circuit in cyclic way. Combinational circuits are generally considered as acyclic structured. However, cyclic loops can be introduced in combinational circuits. The main aim of cyclic circuit is to introduce structural feedback & to avoid the logical feedback in order to get combinational primary output. The study of cyclic circuit includes functional analysis i.e. to determine what values will appear, the timing analysis which determine when these values will appear and the area, as a measure of the number of transistors in the final fabrication. The objective of the study is to design & verification of different combinational circuits in cyclic combinational method by optimizing the area, power and delay. Detailed study of circuit model, its functional and temporal behavior, Synthesis of circuit using cyclic combinational method, Simulation of circuit using standard simulator, Analysis framework including area, power, timing consideration are studied in this work.

Synthesis of reversible circuits is an important research area providing the basis for a design flow of this emerging technology. Recently, in the development of scalable synthesis approaches a significant step forward has been made by a hierarchical method in combination with Shannon decom-position. However, this approach leads to circuits with high costs. In this paper, we propose an alternative that additionally makes use of positive Davio and negative Davio decomposition. We show that the usage of these decomposition types offers several advantages for the synthesis of reversible circuits. Using the proposed approach, on average the number of lines can be reduced by 22%, the number of gates by 22%, and the quantum cost by 32%. In the best case, even reductions of more than 60% are possible.

Optical circuits received significant interest as a promising alternative to existing electronic systems. Because of this, also the synthesis of optical circuits receives increasing attention. However, initial solutions for the synthesis of optical circuits either rely on manual design or rather straight-forward mappings from established data-structures such as BDDs, SoPs/ESoPs, etc. to the corresponding optical netlist. These approaches hardly utilize the full potential of the gate libraries available in this domain. In this paper, we propose an alternative synthesis solution based on AND-Inverter Graphs (AIGs) which is capable of utilizing this potential. That is, a scheme is presented which dedicatedly maps the given function representation to the desired circuit in a one-to-one fashion - yielding significantly smaller circuit sizes. Experimental evaluations confirm that the proposed solution generates optical circuits with up to 97% less number of gates as compared to existing synthesis approaches.

In this article, we introduce a synthesis-based design approach for waveguide filters, including singlets. As is known, a singlet block comprises one resonator coupled to source and load plus an additional coupling between source and load. In this way, a pole-zero pair is produced, thus allowing the introduction of a transmission zero in the frequency response. Structure making that uses cascaded singlets (especially implemented in waveguide technology) has been successfully used to realize compact and quasi-in-line pseudoelliptic filters. The design of this configuration suffers, however, from a severe drawback; while an isolated singlet can be exactly synthesized, when these blocks are put in cascade, nonresonating nodes (NRNs) are required to allow the cascade connection. Consequently, the resulting topology includes both cross couplings and NRNs, for which no exact synthesis solution is till now available (all the design solutions proposed in the literature are based on optimization). The new design procedure here proposed overcomes this drawback, allowing the synthesis of the equivalent circuit of the cascaded-singlet topology. Once this circuit is obtained, the dimensioning of the singlets can be carried out by exploiting a full-wave simulator according to the procedure described in the article. The proposed design approach allows a very accurate initial dimensioning of the filter, which represents an excellent starting point for final adjustments/optimizations. A detailed design example is presented in the article showing how to practically implement the novel procedure. This new approach is also experimentally validated by a waveguide filter prototype, previously designed by optimization and fabricated. It is shown how this filter can be redesigned with the novel procedure, obtaining very similar physical dimensions in a noticeably shorter time.

Kinetic modeling has relied on using a tedious number of mathematical equations to describe molecular kinetics in interacting reactions. The long list of differential equations with associated abstract variables and parameters inevitably hinders readers’ easy understanding of the models. However, the mathematical equations describing the kinetics of biochemical reactions can be exactly mapped to the dynamics of voltages and currents in simple electronic circuits wherein voltages represent molecular concentrations and currents represent molecular fluxes. For example, we theoretically derive and experimentally verify accurate circuit models for Michaelis-Menten kinetics. Then, we show that such circuit models can be scaled via simple wiring among circuit motifs to represent more and arbitrarily complex reactions. Hence, we can directly map reaction networks to equivalent circuit schematics in a rapid, quantitatively accurate, and intuitive fashion without needing mathematical equations. We verify experimentally that these circuit models are quantitatively accurate. Examples include 1) different mechanisms of competitive, noncompetitive, uncompetitive, and mixed enzyme inhibition, important for understanding pharmacokinetics; 2) product-feedback inhibition, common in biochemistry; 3) reversible reactions; 4) multi-substrate enzymatic reactions, both important in many metabolic pathways; and 5) translation and transcription dynamics in a cell-free system, which brings insight into the functioning of all gene-protein networks. We envision that circuit modeling and simulation could become a powerful scientific communication language and tool for quantitative studies of kinetics in biology and related fields.