This paper describes the design of CMOS millimeter-wave voltage controlled oscillators. Varactor, transistor, and inductor designs are optimized to reduce the parasitic capacitances. An investigation of tradeoff between quality factor and tuning range for MOS varactors at 24 GHz has shown that the polysilicon gate lengths between 0.18 and 0.24 micrometer result in both good quality factor (>12) and Cmax/Cmin ratio (~3) in the 0.13-micrometer CMOS process used for the study. The components were utilized to realize a VCO operating around 60 GHz with a tuning range of 5.8 GHz. A 99-GHz VCO with a tuning range of 2.5 GHz, phase noise of --102.7 dBc/Hz at 10-MHz offset and power consumption of 7-15 mW from a 1.5-V supply and a 105-GHz VCO are also demonstrated. This is the CMOS circuit with the highest fundamental operating frequency. The lumped element approach can be used even for VCOs operating near 100-GHz and it results in a smaller circuit area.
Broadband voltage-controlled oscillators are critical to the design of millimeter wave frequency synthesizers. This thesis proposes a design technique that can be used to significantly extend the achievable frequency span of an oscillator. A dual-band oscillator topology is described that can be configured to operate in one of two modes, by an electrical reconfiguration of the negative resistance core around the resonant tank, without switching passive elements within the tank itself. The configuration helps to minimize the difference in phase noise performance between the two modes, while achieving a wide tuning range. To verify the concept, a mm-wave VCO that operates at 30-GHz is designed in a commercial 0.18-um CMOS technology, with an approximate simulated tuning range of 20%. A dual-mode oscillator is also designed in a 0.13-um technology at 60-GHz.
Broadband voltage-controlled oscillators are critical to the design of millimeter-wave (mm-wave) frequency synthesizers. This thesis proposes a design technique that can be used to significantly extend the achievable frequency span of an oscillator. A dual-band oscillator topology is described that can be configured to operate in one of two modes, by an electrical reconfiguration of the negative resistance core around the resonant tank, without switching passive elements within the tank itself. The configuration helps to minimize the difference in phase noise performance between the two modes, while achieving a wide tuning range. To verify the concept, an mm-wave VCO that operates at 30 GHz is designed in a commercial 0.18-um CMOS technology, with an approximate simulated tuning range of 20%. A dual-mode oscillator is also designed in 0.13-um CMOS technology at 60 GHz.
Design of High-Performance CMOS Voltage-Controlled Oscillators presents a phase noise modeling framework for CMOS ring oscillators. The analysis considers both linear and nonlinear operation. It indicates that fast rail-to-rail switching has to be achieved to minimize phase noise. Additionally, in conventional design the flicker noise in the bias circuit can potentially dominate the phase noise at low offset frequencies. Therefore, for narrow bandwidth PLLs, noise up conversion for the bias circuits should be minimized. We define the effective Q factor (Qeff) for ring oscillators and predict its increase for CMOS processes with smaller feature sizes. Our phase noise analysis is validated via simulation and measurement results. The digital switching noise coupled through the power supply and substrate is usually the dominant source of clock jitter. Improving the supply and substrate noise immunity of a PLL is a challenging job in hostile environments such as a microprocessor chip where millions of digital gates are present.
The goal of dissertation is to explore feasibility of designing millimeter-wave (mmWave) circuits in CMOS technology, especially when frequency is close to the maximum oscillation frequency f[subscript max] of the active device. In this dissertation, an embedding network method is proposed to design high efficiency fundamental oscillators and high gain amplifier. First, it reports an approach to designing compact high efficiency mmWave fundamental oscillators operating above the f[subscript max]/2 of the active device. The approach takes full consideration of the nonlinearity of the active device and the finite quality factor of the passive devices to provide an accurate and optimal oscillator design in terms of the output power and efficiency. 213-GHz single-ended and differential fundamental oscillators in 65-nm CMOS technology are presented to demonstrate the effectiveness of the proposed method. Using a compact capacitive transformer design, the single-ended oscillator achieves 0.79-mW output power per transistor (16 [mu]m) at 1.0-V supply and a peak dc-to-RF efficiency of 8.02% (V[subscript DD]=0.80 V) within a core area of 0.0101 mm2, and the measured phase noise is −93.4 dBc/Hz at 1-MHz offset. The differential oscillator exhibits approximately the same performance. A 213-GHz fundamental voltage-controlled oscillator (VCO) with bulk tuning method is also developed in this work. The measured peak efficiency of the VCO is 6.02% with a tuning rang of 2.3% at 0.6-V supply.In order to further improve dc-to-RF efficiency, an optimization-based design methodology is then proposed for high-power and high-efficiency mmWave fundamental oscillators in CMOS technology. The optimization is formulated to take into account the loss of the passive components to result in an optimal circuit design. The proposed approach can produce the final design in a single pass of optimization with a fast and robust convergence profile. A comparative study between the T - and the [pi]-embedding networks is presented. It shows that T -embedding is superior to [pi]-embedding in terms of flexibility in biasing and sensitivity to component Q. A design example of a 215-GHz fundamental oscillator in a 65-nm CMOS technology is presented to demonstrate the effectiveness of the proposed design approach. The oscillator achieves 5.17-dBm peak output power at 1.2-V supply with a corresponding dc-to-RF efficiency 12.3% and a peak efficiency of 13.7%. The measured phase noise is −90.0 dBc/Hz and −116.2 dBc/Hz at 1 MHz and 10 MHz offset, respectively. Lastly, embedding network theory is presented to design high gain amplifier in this dissertation. Two embedding theories, constant GC/U and G[subscript max]/GC, are proposed. A 210-GHz high gain amplifier example is designed. Two 16 [mu]m NMOS transistors consist of a differential circuit with V[subscript DD] = 1.2 V and VG = 0.45 V. The total dc power of the designed 210-GHz amplifier is 12.8 mW. The simulated Gain S21 is 16.66 dB. NF is 7.38 dB. Stability factor k is 3.82 at 210 GHz. The simulated 1dB compression point P1dB, input referred third-order intercept point, IIP3 is -22.33 dB, and -12.97 dB, respectively. These simulated results demonstrate the effectiveness of the proposed design theory.
This book compiles and presents the research results from the past five years in mm-wave Silicon circuits. This area has received a great deal of interest from the research community including several university and research groups. The book covers device modeling, circuit building blocks, phased array systems, and antennas and packaging. It focuses on the techniques that uniquely take advantage of the scale and integration offered by silicon based technologies.
This book provides in-depth coverage of transformer-based design techniques that enable CMOS oscillators and frequency dividers to achieve state-of-the-art performance. Design, optimization, and measured performance of oscillators and frequency dividers for different applications are discussed in detail, focusing on not only ultra-low supply voltage but also ultra-wide frequency tuning range and locking range. This book will be an invaluable reference for anyone working or interested in CMOS radio-frequency or mm-Wave integrated circuits and systems.
Broadband voltage-controlled oscillators are critical to the design of millimeter wave frequency synthesizers. This book proposes a design technique that can be used to significantly extend the achievable frequency span of an oscillator. A dual-band oscillator topology is described that can be configured to operate in one of two modes, by an electrical reconfiguration of the negative resistance core around the resonant tank, without switching passive elements within the tank itself. The configuration helps to minimize the difference in phase noise performance between the two modes, while achieving a wide tuning range. This book includes five chapters and through these chapters the necessary information for designing millimeter wave frequency synthesizers are provided for the readers.
This book is based on the 18 tutorials presented during the 23rd workshop on Advances in Analog Circuit Design. Expert designers present readers with information about a variety of topics at the frontier of analog circuit design, serving as a valuable reference to the state-of-the-art, for anyone involved in analog circuit research and development.
