A Noise-Shifting Differential Colpitts VCO

A novel noise-shifting differential Colpitts VCO is presented. It uses current switching to lower phase noise by cyclostationary noise alignment and improve the start-up condition. A design strategy is also devised to enhance the phase noise performance of quadrature coupled oscillators. Two integrated VCOs are presented as design examples

A general theory of phase noise in electrical oscillators

A general model is introduced which is capable of making accurate, quantitative predictions about the phase noise of different types of electrical oscillators by acknowledging the true periodically time-varying nature of all oscillators. This new approach also elucidates several previously unknown design criteria for reducing close-in phase noise by identifying the mechanisms by which intrinsic device noise and external noise sources contribute to the total phase noise. In particular, it explains the details of how 1/f noise in a device upconverts into close-in phase noise and identifies methods to suppress this upconversion. The theory also naturally accommodates cyclostationary noise sources, leading to additional important design insights. The model reduces to previously available phase noise models as special cases. Excellent agreement among theory, simulations, and measurements is observed

Millimeter-Wave CMOS Digitally Controlled Oscillators for Automotive Radars

All-Digital-Phase-Locked-Loops (ADPLLs) are ideal for integrated circuit implementations and effectively generate frequency chirps for Frequency-Modulated-Continuous-Wave (FMCW) radar. This dissertation discusses the design requirements for integrated ADPLL, which is used as chirp synthesizer for FMCW automotive radar and focuses on an analysis of the ADPLL performance based on the Digitally-Controlled-Oscillator (DCO) design parameters and the ADPLL configuration. The fundamental principles of the FMCW radar are reviewed and the importance of linear DCO for reliable operation of the synthesizer is discussed. A novel DCO, which achieves linear frequency tuning steps is designed by arranging the available minimum Metal-Oxide-Metal (MoM) capacitor in unique confconfigurations. The DCO prototype fabricated in 65 nm CMOS fullls the requirements of the 77 GHz automotive radar. The resultant linear DCO characterization can effectively drive a chirp generation system in complete FMCW automotive radar synthesizer

Design of a 41.14-48.11 GHz triple frequency based VCO

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. Growing deployment of more efficient communication systems serving electric power grids highlights the importance of designing more advanced intelligent electronic devices and communication-enabled measurement units. In this context, phasor measurement units (PMUs) are being widely deployed in power systems. A common block in almost all PMUs is a phase locked oscillator which uses a voltage controlled oscillator (VCO). In this paper, a triple frequency based voltage controlled oscillator is presented with low phase noise and robust start-up. The VCO consists of a detector, a comparator, and triple frequency. A VCO starts-up in class AB, then steadies oscillation in class C with low current oscillation. The frequency of the VCO, which is from 13.17 GHz to 16.03 GHz, shows that the frequency is tripling to 41.14-48.11 GHz. Therefore, its application is not limited to PMUs. This work has been simulated in a standard 0.18 µm CMOS process. The simulated VCO achieves a phase noise of -99.47 dBc/Hz at 1 MHz offset and -121.8 dBc/Hz at 10 MHz offset from the 48.11 GHz carrier

Survey on individual components for a 5 GHz receiver system using 130 nm CMOS technology

La intención de esta tesis es recopilar información desde un punto de vista general sobre los diferentes tipos de componentes utilizados en un receptor de señales a 5 GHz utilizando tecnología CMOS. Se ha realizado una descripción y análisis de cada uno de los componentes que forman el sistema, destacando diferentes tipos de configuraciones, figuras de mérito y otros parámetros. Se muestra una tabla resumen al final de cada sección, comparando algunos diseños que se han ido presentando a lo largo de los años en conferencias internacionales de la IEEE.The intention of this thesis is to gather information from an overview point about the different types of components used in a 5 GHz receiver using CMOS technology. A review of each of the components that form the system has been made, highlighting different types of configurations, figure of merits and parameters. A summary table is shown at the end of each section, comparing many designs that have been presented over the years at international conferences of the IEEE.Departamento de Ingeniería Energética y FluidomecánicaGrado en Ingeniería en Electrónica Industrial y Automátic

An enhanced swing differential Colpitts CMOS VCO for low-voltage operation

An enhanced swing differential Colpitts VCO (ESDC-VCO) dramatically improves the swing of a Colpitts VCO by allowing the signal to swing below ground and above the supply voltage. Fabricated in a 1P8M 0.13 um CMOS process, the ESDC-VCO operates at 4.9GHz with a 0.475-V supply and consumes 2.7mW. The measured phase noise is -136.2 dBc/Hz at a 3-MHz frequency offset. The ESDC-VCO employs digital amplitude control and achieves a Figure of merit (FOM) of 196.2 dBc/Hz, making it the highest performing integrated LC oscillator to date

RF CMOS Oscillators for Modern Wireless Applications

While mobile phones enjoy the largest production volume ever of any consumer electronics products, the demands they place on radio-frequency (RF) transceivers are particularly aggressive, especially on integration with digital processors, low area, low power consumption, while being robust against process-voltage-temperature variations. Since mobile terminals inherently operate on batteries, their power budget is severely constrained. To keep up with the ever increasing data-rate, an ever-decreasing power per bit is required to maintain the battery lifetime. The RF oscillator is the second most power-hungry block of a wireless radio (after power amplifiers). Consequently, any power reduction in an RF oscillator will greatly benefit the overall power efficiency of the cellular transceiver. Moreover, the RF oscillators' purity limits the transceiver performance. The oscillator's phase noise results in power leakage into adjacent channels in a transmit mode and reciprocal mixing in a receive mode. On the other hand, the multi-standard and multi-band transceivers that are now trending demand wide tuning range oscillators. However, broadening the oscillator’s tuning range is usually at the expense of die area (cost) or phase noise. The main goal of this book is to bring forth the exciting and innovative RF oscillator structures that demonstrate better phase noise performance, lower cost, and higher power efficiency than currently achievable. Technical topics discussed in RF CMOS Oscillators for Modern Wireless Applications include: Design and analysis of low phase-noise class-F oscillators Analyze a technique to reduce 1/f noise up-conversion in the oscillators Design and analysis of low power/low voltage oscillators Wide tuning range oscillators Reliability study of RF oscillators in nanoscale CMO

Investigation on LIGA-MEMS and on-chip CMOS capacitors for a VCO application

Modern communication systems require high performance radio frequency (RF) and microwave circuits and devices. This is becoming increasingly challenging to realize in the content of cost/size constraints. Integrated circuits (ICs) satisfy the cost/size requirement, but performance is often sacri¯ced. For instance, high quality factor (Q factor) passive components are difficult to achieve in standard silicon-based IC processes.In recent years, microelectromechanical systems (MEMS) devices have been receiving increasing attention as a possible replacement for various on-chip passive elements, offering potential improvement in performance while maintaining high levels of integration. Variable capacitors (varactor) are common elements used in various applications. One of the MEMS variable capacitors that has been recently developed is built using deep X-ray lithography (as part of the LIGA process). This type of capacitor exhibits high quality factor at microwave frequencies.The complementary metal oxide semiconductor (CMOS) technology dominates the silicon IC process. CMOS becomes increasingly popular for RF applications due to its advantages in level of integration, cost and power consumption. This research demonstrates a CMOS voltage-controlled oscillator (VCO) design which is used to investigate methods, advantages and problems in integrating LIGA-MEMS devices to CMOS RF circuits, and to evaluate the performance of the LIGA-MEMS variable capacitor in comparison with the conventional on-chip CMOS varactor. The VCO was designed and fabricated using TSMC 0.18 micron CMOS technology. The core of the VCO, including transistors, resistors, and on-chip inductors was designed to connect to either an on-chip CMOS varactor or an off-chip LIGA-MEMS capacitor to oscillate between 2.6 GHz and 2.7 GHz. Oscillator phase noise analysis is used to compare the performance between the two capacitors. The fabricated VCO occupied an area of 1 mm^2.This initial attempt at VCO fabrication did not produce a functional VCO, so the performance of the capacitors with the fabricated VCO could not be tested. However, the simulation results show that with this LIGA-MEMS capacitor, a 6.4 dB of phase noise improvement at 300 kHz offset from the carrier is possible in a CMOS-based VCO design