Simulation of mutually coupled oscillators using nonlinear phase macromodels

Design of integrated RF circuits requires detailed insight in the behavior of the used components. Unintended coupling and perturbation effects need to be accounted for before production, but full simulation of these effects can be expensive or infeasible. In this paper we present a method to build nonlinear phase macromodels of voltage controlled oscillators. These models can be used to accurately predict the behavior of individual and mutually coupled oscillators under perturbation at a lower cost than full circuit simulations. The approach is illustrated by numerical experiments with realistic designs

Simulation of three mutually coupled oscillators

In a practical multipurpose high frequency circuit, different oscillators are not completely isolated from each other. Instead, they interact with the environment, or with other oscillator. The interference between different oscillators may lead to generation of undesired signals. Therefore, the effect of oscillators on each other must be considered in the circuit design. As oscillators have nonlinear behavior, simulation of some of them which are coupled to each other needs more attention. In this report we present a mathematical model for three mutually coupled voltage controlled oscillators and solve it by a numerical method. The approach is illustrated by numerical experiments on realistic designs

O-MOORE-NICE!: new methodologies and algorithms for design and simulation of analog integrated circuits

No abstract

Review of Injected Oscillators

Oscillators are critical components in electrical and electronic engineering and other engineering and sciences. Oscillators are classified as free-running oscillators and injected oscillators. This chapter describes the background necessary for the analysis and design of injected oscillators. When an oscillator is injected by an external periodic signal mentioned as an injection signal, it is called an injected oscillator. Consequently, two phenomena occur in the injected oscillators: (I) pulling phenomena and (II) locking phenomena. For locking phenomena, the oscillation frequency of the injection signal must be near free-running oscillation frequency or its sub-/super-harmonics. Due to these phenomena are nonlinear phenomena, it is tough to achieve the exact equation or closed-form equation of them. Therefore, researchers are scrutinizing them by different analytical and numerical methods for accomplishing an exact inside view of their performances. In this chapter, injected oscillators are investigated in two main subjects: first, analytical methods on locking and pulling phenomena are reviewed, and second, applications of injected oscillators are reviewed such as injection-locked frequency dividers at the latter. Furthermore, methods of enhancing the locking range are introduced

Model order reduction techniques in microelectromechanics

Ph.DDOCTOR OF PHILOSOPH

Automotive Inductive Position Sensor

Inductive angular position sensors (IAPS) are widely used for high accuracy and low cost angular position sensing in harsh automotive environments, such as suspension height sensor and throttle body position sensor. These sensors ensure high resolution and long lifetime due to their contactless sensing mode and their simple structure. Furthermore, they are suitable for wider application areas. For instance, they can be miniaturized to fit into a compact packaging space, or be adopted to measure the relative angle of multiple rotating targets for the purposes of torque sensing. In this work, a detailed SIMULINK model of an IAPS is first proposed in order to study and characterize the sensor performance. The model is validated by finite element analysis and circuit simulation, which provides a powerful design tool for sensor performance analysis. The sensor error introduced by geometry imperfection is thoroughly investigated for two-phase and three-phase configurations, and a corresponding correction method to improve the accuracy is proposed. A design optimization method based on the response surface methodology is also developed and used in the sensor development. Three types of sensors are developed to demonstrate the inductive sensor technology. The first type is the miniaturized inductive sensor. To compensate for the weak signal strength and the reduced quality (Q) factor due to the scaling down effect, a resonant rotor is developed for this type of sensor. This sensor is fabricated by using the electrodeposition technique. The prototype shows an 8mm diameter sensor can function well at 1.5mm air gap. The second type is a steering torque sensor, which is designed to detect the relative torsional angle of a rotating torsional shaft. It demonstrates the mutual coupling of multiple inductive sensors. By selecting a proper layout and compensation algorithm, the torque sensor can achieve 0.1 degree accuracy. The third type is a passive inductive sensor, which is designed to reduce power consumption and electromagnetic emissions. The realization and excellent performance of these three types of sensors have shown the robustness of the inductive sensor technology and its potential applications. The research conducted in this dissertation is expected to improve understanding of the performance analysis of IAPS and provide useful guidelines for the design and performance optimization of inductive sensors

How to stop a biological clock: Point of singularity

Many processes in organisms proceed rhythmically. There are, for instance, daily rhythms as adaptations to the 24 hour time structure of the environment, annual rhythms as adaptations to the course of the year, but also shorter rhythms without any correlate to the environment such as the heart beat and respiration. Such rhythms can be stopped by a disturbance by e.g a light pulse given at a certain time point of an oscillation with a special strength. Models show, that the underlying oscillator is brought from a limit cycle into a singular point. Examples for daily rhythms, for an annual rhythm, and for the heart beat are presented, in which the rhythm is stopped. How this property can be used in the praxis is demonstrated by the case of the sudden heart-circulation collaps and in the photoperiodic flower induction of a plant.Viele Vorgänge bei Organismen verlaufen rhythmisch. So gibt es zum Beispiel Tagesrhythmen als Anpassung an die 24 stündige Zeitstruktur der Umwelt, Jahresrhythmen als Anpassung an den Jahreslauf, aber auch kürzere Rhythmen, die keine Korrelate in der Umwelt haben wie der Herzschlag oder die Atmung. Solche Rhythmen können durch Störungen zum Erliegen gebracht werden, zum Beispiel durch einen Lichtpuls, der zu einem ganz bestimmten Zeitpunkt der Schwingung mit einer besonderen Stärke gegeben wird. Modelle zeigen, dass der zugrunde liegende Oszillator von einem Grenzzyklus in einen singulären Punkt gebracht wird. Beispiele für Tagesrhythmen, für einen Jahresrhythmus und für den Herzschlag werden vorgestellt, bei denen der Rhythmus gestoppt wird. Wozu diese Eigenschaft in der Praxis benutzt werden kann, wird am plötzlichen Herz-Kreislauf Kollaps und der photoperiodischen Blühinduktion einer Pflanze gezeigt