CAD Simulation Research Articles

Low Cost RF Amplifier for Community TV

he capability of television to deliver audio video makes this media become the most effective method to spread information. This paper presents an experiment of RF amplifier design having low-cost design and providing sufficient RF power particularly for community television. The RF amplifier consists of two stages of amplifier. The first stage amplifier was used to leverage output of TV modulator from 11dBm to enable to drive next stage amplifier. CAD simulation and fabrication were run to reach optimum RF amplifier design circuit. The associated circuit was made by determining stability circle, stability gain, and matching impedance. Hence, the average power of first stage RF amplifier was 24.68dBm achieved. The second stage used RF modules which was ready match to 50 ohm for both input and output port. The experiment results show that the RF amplifier may operate at frequency ranging from 174 to 230MHz. The average output power of the 2nd stage amplifier was 33.38 Watt with the overall gain of 20.54dB. The proposed RF amplifier is a cheap way to have a stable RF amplifier for community TV. The total budget for the designed RF amplifier is only a 1/5 compared to local design of final TV amplifier.

DC/Dynamic Surface-Potential-Based-Model of InGaZnO Transistors for Circuit Simulation

A compact model of amorphous indium gallium zinc oxide thin-film transistors, suitable for CAD simulators, is proposed. The model is simple, symmetric, and accurately accounts for the subthreshold, linear, and saturation regimes via a unique formulation. It accounts for both trapped and free charges by means of multiple-trapping-and-release and percolation in the conduction band. Aim of the paper is to work out the analytic expression of the current and of the terminal charges, along with the surface potential and the electric field as a function of position in the channel. The availability of the surface potential and of the electric field is the key to model advanced physical effects as, for example, the carrier injection from the electrodes into the channel.

Learning And-Or Models to Represent Context and Occlusion for Car Detection and Viewpoint Estimation.

This paper presents a method for learning an And-Or model to represent context and occlusion for car detection and viewpoint estimation. The learned And-Or model represents car-to-car context and occlusion configurations at three levels: (i) spatially-aligned cars, (ii) single car under different occlusion configurations, and (iii) a small number of parts. The And-Or model embeds a grammar for representing large structural and appearance variations in a reconfigurable hierarchy. The learning process consists of two stages in a weakly supervised way (i.e., only bounding boxes of single cars are annotated). Firstly, the structure of the And-Or model is learned with three components: (a) mining multi-car contextual patterns based on layouts of annotated single car bounding boxes, (b) mining occlusion configurations between single cars, and (c) learning different combinations of part visibility based on CAD simulations. The And-Or model is organized in a directed and acyclic graph which can be inferred by Dynamic Programming. Secondly, the model parameters (for appearance, deformation and bias) are jointly trained using Weak-Label Structural SVM. In experiments, we test our model on four car detection datasets - the KITTI dataset [1], the PASCAL VOC2007 car dataset [2], and two self-collected car datasets, namely the Street-Parking car dataset and the Parking-Lot car dataset, and three datasets for car viewpoint estimation - the PASCAL VOC2006 car dataset [2], the 3D car dataset [3], and the PASCAL3D+ car dataset [4]. Compared with state-of-the-art variants of deformable part-based models and other methods, our model achieves significant improvement consistently on the four detection datasets, and comparable performance on car viewpoint estimation.

Gripper with Average Continuous Reconfigurability for Industrial Robots

Anthropomorphic grippers for robots are used increasingly in robotic applications for handling and assembly. Currently there are several versions of anthropomorphic grippers as projects, prototypes or commercial variants that due to high prices or even for very high ones, are not available for current applications. Among them, high functionality at a relatively low complexity can be noticed in the case of reconfigurable grippers with high reconfigurability, Barrett Hand type. In this context, it is justified finding alternative solutions at lower prices at a lower reconfigurability, with acceptable functionality for current robotic operations. The paper presents an original version of modular anthropomorphic gripper continuous average reconfigurability, with three fingers. There are mentioned, briefly, major structural, kinematic and static issues, a CAD model and CAD simulation for gripping several types of pieces. Furthermore, we intend to achieve a prototype and test it by mounting on an industrial robot.

Design and Analysis of 32-Bit CLA Using Energy Efficient Adiabatic Logic for Ultra-Low-Power Application

This paper shows that a conventional semi-custom design-flow based on a energy efficient adiabatic logic (EEAL) cell library allows any VLSI designer to design and verify complex adiabatic arithmetic units in a simple way, thus, enjoying the energy reduction benefits of adiabatic logic. A family of semi-custom EEAL-based 32-bit carry-lookahead adder (CLA) has been designed in a TSMC 90-nm CMOS process technology and verified by CADENCE Design suite. Differential cascode voltage swing (DCVS) logic has been used to implement the newly proposed EEAL and it uses only a sinusoidal clock supply to ensure correct operation. Post-layout simulations show that semi-custom adiabatic arithmetic units can save significant amount of energy, as compared to the previously reported single clocked adiabatic logic and logically equivalent static CMOS implementation. Extensive CADENCE simulations have been done for the verification of the functionality of the proposed logic structure.

Multi-Threshold Voltage CMOS Design for Low-Power Half Adder Circuit

The new era of portable electronic devices demands lesser power dissipation for longer battery life and design compactability. Leakage current and leakage power are dominating factors which greatly affect the power consumption in low voltage and low power applications. For many numerical representations of binary numbers, combinational circuits like adder, encoder, multiplexer, etc. are useful circuits for arithmetic operation. A novel high speed and low power half adder cell is introduced here which consists of AND gate and OR gate. This cell shows high speed, lower power consumption than conventional half adder. In CMOS technology, transistors used have small area and low power consumption. It is used in various applications like adder, subtract or, multiplexer, ALU and microprocessors digital VLSI systems. As the scaling technology reduces, the leakage power increases. In this paper, multi threshold complementary metal oxide semiconductor (MTCMOS) technique is proposed to reduce the leakage current and leakage power. MTCMOS is an effective circuit level technique that increases the performance of a cell by using both low- and high-threshold voltage transistors. Leakage current is reduced by 85.37% and leakage power is reduced by 87.45% using MTCMOS technique as compared to standard CMOS technique. The half adder design simulation work was performed by cadence simulation tool at 45-nm technology.

A Computer-Aided-Design (CAD) System for Four-Step Three-Dimensional Braiding

To estimate the precise mechanical properties of the three-dimensional (3D) braided composite, a geometric study is needed. Owing to the complexity of the yarn paths inside the preform, the geometric modeling for 3D braided composite is always time consuming. In this paper, an efficient method, namely preform boundary reflection (PBR) method, is proposed for motion model construction in geometric study. Furthermore, the CAD simulation system was developed for integral geometric descriptions of 3D braided preform with different parameters. Compared with the traditional method, the novel method significantly simplifies the simulation process without affecting the precision of geometric structure. As a result, the structure design for composite preform is effectively accelerated. The new method establishes the foundation of microstructure and mechanical properties analysis for the preforms with complex geometric structures.

Reconfigurable Anthropomorphic Gripper with Three Fingers: Synthesis, Analysis, and Simulation

This paper shows the steps of structural synthesis and analysis, kinematic synthesis and analysis and CAD constructive design of a reconfigurable modular anthropomorphic gripper with three fingers. Modularity refers to the fact that the gripper variants can be obtained with only two modules, namely a platform and a finger. Reconfigurability refers to the fact that the main variants of the gripper can be obtained by changing the relative position of the fingers. It is demonstrated that the three-finger gripper has four main configurations that provide important functionality even reported to the functionality of a three-finger gripper with continuous reconfigurability. To verify correct operation, functional CAD simulation is performed, and for dynamic operation simulation, we turn to the advanced software ADAMS. An important advantage of this type of gripper, compared to those with continuous reconfigurability, is much lower price at a relatively good functionality for current robotic gripping operations. The paper makes possible subsequent turn to prototype, testing the gripper operation, as it is mounted on an industrial robot, and optimization of its operation by equipping it with contact sensors. The simulation of the gripper operation in virtual environment and data transmission to the real gripper is a solution of interest that will be studied in future research.

СРАВНЕНИЕ МЕТОДОВ НАЧЕРТАТЕЛЬНОЙ ГЕОМЕТРИИ И 3D КОМПЬЮТЕРНОГО ГЕОМЕТРИЧЕСКОГО МОДЕЛИРОВАНИЯ ПО ТОЧНОСТИ, СЛОЖНОСТИ И ЭФФЕКТИВНОСТИ

Urgent educational problem of inconsistency of content of the course of descriptive geometry (DG) with the trends in the development of CAD and geometric simulation is considered. While the development is aimed at expanding the scope of computer 3D geometric simulation the teaching of descriptive geometry projection methods continues despite the fact that they are in no demand in practical applications. To compare the estimations of versions of solutions in descriptive geometry and 3D five specific problems of the nomination in descriptive geometry of All-Russian Olympiad 2014 are considered. They are the construction of sphere, tangent to the paraboloid; determining the points of intersection of the ellipse defined by the axes, with a circle (without the ellipse); finding the reference points of the ellipse section and its projections; construction of a tetrahedron by one projection of its face; as well as the defining the points of intersection of the circle with an elliptical cone. The detailed versions of solutions of descriptive geometry and 3D are given for each problem. The comparison of versions of the solution according to the geometrical accuracy is done. It is offered to estimate not an abstract accuracy which corresponds to constructions made by aperfect caliper and a ruler but the real accuracy independently of methods of its achievement. It’s shown that with the computer realization of both variants their real accuracy is either equal or 3D is much better than DG. The estimation of the complexity of task solutions is given. The amount of information needed for the solution is taken as a criterion. The author makes the conclusion that generally 3D versions are easier than DG. The examples show that 3D solutions can be easily supplemented with researches of a solvable problem. Much higher visualization, accessibility and universality of 3D versions are highlighted. The author makes the conclusion about much higher general effectiveness of computer 3D variants and methods of solving the structural problems and the necessity of transfer to new training course of 3d theory. Keywords: descriptive geometry, computer graphics, 3D modeling, structural problems, geometrical accuracy, complexity and effectiveness of structural problems.

The Exploration of Biasing Voltage Range on Implantable Microscale Electrochemical Sensors for Post-Surgery Cancer Recurrence Monitoring

Cancer surgery prognosis currently relies heavily on expensive diagnostics devices that have limited availability to patients. Minute-to-minute cancer recurrence monitoring device is needed. This paper investigates a novel design and simulation of Implantable micro-scale, minute-to-minute sensors of low manufacture cost. In Cadence simulation software, electrochemical sensor array circuit in 0.35 micron complementary metal oxide semiconductor (CMOS) process was designed. The simulated circuit supported both pH ISFET sensor and soluble oxygen level O2-FET sensor. The simulation result showed that the circuit’s output voltage has optimal sensitivity when ISFET Vgate was biased at range of 2.29-2.49 volts. The output voltage in this biasing scheme varies linearly with the input voltage Vgate making it ideal region for monitoring of cancer. The appropriate biasing of ISFET Vgate voltage found by simulation is within 2.29-2.49 volts. In the case of pH measurements, the sensitivity can be up to 0.02 pH in a minute-to-minute pH probing device for cancer prognosis tracking. Other chemical probes such as O2-FET and Oct4 sensors are also supported by the device architecture.

Experimental and Simulation Analysis for the Impact of a Two-Link Chain with Granular Matter

The resistance force of the granular matter is modeled as a linear superposition of a static (quadratic depth-dependent) resistance force and a dynamic (quadratic velocity-dependent) frictional force. The impact is defined from the moment the end point of the system comes in contact with the granular matter surface until the vertical linear velocity of the end point is zero. The variables of interest are the final depth at the end of the penetration phase and the stopping time. The results for a two-link kinematic chain with two points of contact were compared to the results obtained by applying the resistance force formulation developed to corresponding CAD simulation models. The results revealed that the final displacement increases with initial velocity, while the stopping time decreases. The sensitivity to the initial velocity was studied and an improvement to the resistance force formulated as a result. A series of expressions are proposed for the resistance force coefficients.

Reaction forces identification of a quadruped robot with parallel-serial leg structure

Interactions between feet and environment influence the stability and mobility of legged robot. This paper proposes a model to indirectly identify 3 degrees of freedom feet reaction forces for a quadruped robot with parallel-serial legs. The research platform is called Baby-Elephant: a heavy-duty four-legged robot designed for nuclear plant maintenance and disaster relief purposes. Each leg has three hydraulic actuators. With the pressure data from pump and hydraulic actuators, a double-chamber model with experimental derived friction is used to obtain the actuated force. The reaction forces model, including joint and foot forces, is simplified into an explicit function. Comparison between CAD simulation and analytical results shows the effectiveness of the model. A walking experiment with load cells proves the model is validate in practical application. The proposed model is used to identify the foot contact phase and the zero momentum point during crawling gait walking.

Robotized Montage Unit which Uses an Anthropomorphic Gripper with Five Fingers: CAD Modelling and Simulation

This paper presents an original integrated solution of montage robotization of assemblies of small and medium complexity. The robotic station (the robotized cell) proposed contains a joint industrial robot equipped with an anthropomorphic gripper with five fingers, two feeders, a montage table and a storage terminal. CAD modelling of the whole system and functional simulation are performed, which certifies the validity of its correct operation. The gripper used is anthropomorphic with five fingers and five degrees of freedom with a relatively simple structure but high functionality. The gripper, adapted by a popular variant is realized as prototype at low cost, through rapid prototyping, and tested. The gripper control is possible through the advanced method of human hand gestures capture with a Motion Leap device and their transmission through a virtual interface to the real gripper. In perspective, it is considered mounting the gripper in an improved variant, on a real robot and testing the operation of the proposed montage scenario.

Design of an Output-Capacitorless LDO Regulator with Adaptive Power Transistors

This paper presents a bandgap reference and an output-capacitorless LDO regulator with adaptive power transistors. The bandgap reference consists of a current reference circuit, a bipolar transistor and proportional-to-absolute-temperature (PTAT) voltage generators. The proposed LDO improves load transient and light load efficiency by permitting the regulator to transform itself between 2-stage and 3-stage topologies, depending on the load current condition. Cadence simulation with SMIC 0.18 μm process shows that the bandgap reference generates a reference voltage 569 mV and the quiescent current is only 0.23 μA, the proposed LDO generates an output voltage 1 V, the quiescent current is 0.88 μA (including bandgap reference) at no-load condition, the undershoot /overshoot voltage is 187 mV/152 mV and the settling time is 5 μs as load current suddenly changes from 0 to 100 mA, or vice versa.

Research of Signal Integrality in PCB Design for ARM9 Core Board

To solve the signal integrity problem which exists in ARM9 core PCB board design is the foundation to ensure high-speed ARM9 embedded system’s security and reliability. This paper make research on reflection, crosstalk and timing issues which exist in the design process of the ARM9 embedded system core PCB board, and perform simulation with the help of Cadence simulation and analysis software and IBIS model. The results show that match impedance is the key to solve the reflection problem,appropriate length and line spacing is help to solve the crosstalk problem,make the clock lines and data lines isometric can effectively reduce the timing issues.

Modeling of Elevated Temperatures Impact on Single Event Transient in Advanced CMOS Logics Beyond the 65-nm Technological Node

This work presents the modeling of the impact of elevated temperatures on the SET occurrence and their characteristics in an IBM 65-nm Bulk CMOS technology. The calculations are performed by the combined MUSCA SEP3 platform and Cadence simulations. Comparisons between predictions and experimental data of the impact of temperature on the SET cross section(s) and the SET pulse-width are consistent. A different behavior between n-MOS and p-MOS transistors are exhibited at elevated temperatures. A basic radiation mitigation technique is presented and evaluated with the aim to reduce the SET occurrence and characteristics. The die-shrink to 28-nm is also investigated with the goal to investigate the impact of the technology scale on the charge sharing phenomena at elevated temperatures. The interest of this work is to propose a modeling of the behavior of CMOS devices at high temperatures with the aim to help designers to anticipate the soft error sensitivity taking into account the technological scale.

Practical and reliable carbide drill grinding methods based on a five-axis CNC grinder

The carbide drill is an important hole-machining tool. Modern processing solutions set higher requirements for the accuracy and efficiency of carbide drill manufacturing. This paper presents a detailed study of mathematical models of the spiral groove, conical flank, and cutter clearance and proposes three practical and reliable grinding methods using only one standard straight wheel. The spiral groove is ground by controlling three crucial structure parameters: the spiral angle, core diameter, and rake angle. The conical flank is ground by controlling the relief angle, chisel edge angle, and apex angle. The cutter clearance is ground by controlling the ridge width and clearance depth. With these schemes, the wheel position parameters can be computed conveniently and quickly using computer programming, overcoming the low calculation accuracy of empirical formulae and thereby enhancing the efficiency. Using the wheel position parameters, the NC codes applicable to five-axis CNC grinders can be obtained. Furthermore, the reliability of the proposed grinding methods can be verified through CAD simulation and practical manufacture on a five-axis CNC grinder.

In brief

PAGE 786 Research from Pakistan and the UK presents a novel dual-port diversity/MIMO antenna for UWB applications. The system is compact and suitable for non-planar applications as well as being reconfigurable. The MIMO elements can be placed in stacked/back-to-back as well as in orthogonal/around-corner arrangements. Compact and reconfigurable systems (including UWB) are important for Wide Personal Area Networks. PAGE 826 A system that implements a temperature gradient sensor and a beacon signal transmitter has been proposed in work from Spain. The system is fully autonomous and self-powered by energy harvesting from a very low temperature gradient. It was originally conceived to power a low-power satellite beacon and has found applications in automatic air conditioning and heating systems. Novel dual-port diversity/MIMO antenna has potential ultrawide band applications PAGE 833 A novel computational technique to study the terminal influence inside the three-dimensional nano-scale MOSFET using Technology CAD simulations is shown in work from the United States. Within the MOSFET, the derivative of the electrostatic potential can be taken with respect to voltages at each terminal; when these derivatives are summed together, they always sum to unity. These functions can be used to quantify the relative influence or control of terminals anywhere inside the MOSFET, including the channel. Temperature gradient sensor and beacon signal transmitter used in automated air-conditioning and heating systems PAGE 817 Researchers in the United States have demonstrated the first contactless radio frequency (RF) probes for on-wafer characterisation of microwave integrated circuits (MICs) at temperatures as high as 200°C. The high-temperature contactless probing techniques overcome the limitations of conventional ground-signal-ground coplanar waveguide probes, which rely on good physical contact. They provide a fast, reliable and inexpensive method to quickly screen MICs for high temperature RF telemetry. Novel computational technique is presented to study the terminal influence inside the three-dimensional nano-scale MOSFET PAGE 799 Researchers in Japan present a PLZT capacitor fabrication process with better hydrogen degradation resistance and fatigue endurance by adding a thin aluminium-doped zinc oxide (AZO) buffer layer. This could be applied to ferroelectric random access memory, MEMS and piezoelectric fields. The hydrogen degradation resistance of the PLZT capacitors was improved by over 80% of an initial polarisation value. Contactless radio frequency probes provide a fast, reliable and inexpensive method to quickly screen MICs for high temperature RF telemetry Issue 1 of the IET's latest Letters journal is now available at www.theiet.org/htl with trial access to all content throughout 2014

Design of Low Power Integrated CMOS Potentiometric Biosensor for Direct Electronic Detection of DNA Hybridization

The purpose of this research is to design a low power integrated complementary metal oxide semiconductor (CMOS) detection circuit for charge-modulated field-effect transistor (CMFET) and it is used for the detection of deoxyribonucleic acid (DNA) hybridization. With the available CMOS technology, it allows the realization of complete systems which integrate the sensing units and transducing elements in the same device. Point-of-care (POC) testing device is a device that allows anyone to operate anywhere and obtain immediate results. One of the important features of POC device is low power consumption because it is normally battery-operated. The power consumption of the proposed integrated CMOS detection circuit requires only 14.87 mW. The detection circuit will amplify the electrical signal that comes from the CMFET to a specified level in order to improve the recording characteristics of the biosensor. Self-cascode topology was used in the drain follower circuit in order to reduce the channel length modulation effect. The proposed detection circuit was designed with 0.18µm Silterra CMOS fabrication process and simulated under Cadence Simulation Tool.

Transient Response Enhancement with Fast Transient Controller for Capacitor-Less LDO Regulator

This paper presents a capacitor-less CMOS low dropout regulator (LDO) with a push-pull class AB amplifier, and a fast transient controller to achieve a better transient response. The undershoot/overshoot voltage and the settling time are effectively reduced. Through the theoretical analysis of the circuit, cadence simulation with SMIC 0.18μm process and under the condition of the input voltage range 1.4~4 V shows the output voltage is 1.2 V, with the fast controller the total quiescent current is 8.2 μA, the undershoot /overshoot voltage is 97 mV/47 mV and the settling time is 0.3 μs as load current suddenly changes from 1 to 100 mA, or vice versa. Compared with this paper without fast transient controller, the undershoot voltage, the overshoot voltage and the settling time are enhanced by 30%, 64% and 80%, respectively.