Quadrature Frequency Synthesis for Wideband Wireless Transceivers

University of Minnesota Ph.D. dissertation. May 2014. Major: Electrical Engineering. Advisor: Ramesh Harjani. 1 computer file (PDF); xi, 112 pages.In this thesis, three different techniques pertinent to quadrature LO generation in high data rate and wideband RF transceivers are presented. Prototype designs are made to verify the performance of the proposed techniques, in three different technologies: IBM 130nm CMOS process, TSMC 65nm CMOS process and IBM 32nm SOI process. The three prototype designs also cover three different frequency bands, ranging from 5GHz to 74GHz. First, an LO generation scheme for a 21 GHz center-frequency, 4-GHz instantaneous bandwidth channelized receiver is presented. A single 1.33 GHz reference source is used to simultaneously generate 20 GHz and 22 GHz LOs with quadrature outputs. Injection locking is used instead of conventional PLL techniques allowing low-power quadrature generation. A harmonic-rich signal, containing both even and odd harmonics of the input reference signal, is generated using a digital pulse slimmer. Two ILO chains are used to lock on to the 10th and 11th harmonics of the reference signal generating the 20 GHz and the 22 GHz quadrature LOs respectively. The prototype design is implemented in IBM's 130 nm CMOS process, draws 110 mA from a 1.2 V supply and occupies an active area of 1.8 square-mm. Next, a wide-tuning range QVCO with a novel complimentary-coupling technique is presented. By using PMOS transistors for coupling two VCOs with NMOS gm-cells, it is shown that significant phase-noise improvement (7-9 dB) can be achieved over the traditional NMOS coupling. This breaks the trade-off between quadrature accuracy and phase-noise, allowing reasonable accuracy without a significant phase-noise hit. The proposed technique is frequency-insensitive, allowing robust coupling over a wide tuning range. A prototype design is done in TSMC 65nm process, with 4-bits of discrete tuning spanning the frequency range 4.6-7.8 GHz (52% FTR) while achieving a minimum FOM of 181.4dBc/Hz and a minimum FOMT of 196dBc/Hz. Finally, a wide tuning-range millimeter wave QVCO is presented that employs a modified transformer-based super-harmonic coupling technique. Using the proposed technique, together with custom-designed inductors and metal capacitors, a prototype is designed in IBM 32nm SOI technology with 6-bits of discrete tuning using switched capacitors. Full EM-extracted simulations show a tuning range of 53.84GHz to 73.59GHz, with an FOM of 173 dBc/Hz and an FOMT of 183 dBc/Hz. With 19.75GHz of tuning range around a 63.7GHz center frequency, the simulated FTR is 31%, surpassing all similar designs in the same band. A slight modification in the tank inductors would enable the QVCO to be employed in multiple mm-Wave bands (57-66 GHz communication band, 71-76 GHz E-band, and 76-77 GHz radar band)

RF CMOS quadrature voltage-controlled oscillator design using superharmonic coupling method.

Chung, Wai Fung.Thesis (M.Phil.)--Chinese University of Hong Kong, 2007.Includes bibliographical references (leaves 98-100).Abstracts in English and Chinese.摘要 --- p.IIIACKNOWLEDGEMENT --- p.IVCONTENTS --- p.VLIST OF FIGURES --- p.VIIILIST OF TABLES --- p.XLIST OF TABLES --- p.XChapter CHAPTER 1 --- INTRODUCTION --- p.1Chapter 1.1 --- Motivation --- p.1Chapter 1.2 --- Receiver Architecture --- p.3Chapter 1.2.1 --- Zero-IF Receivers --- p.4Chapter 1.2.2 --- Low-IF Receivers --- p.6Chapter 1.2.2.1 --- Hartley Architecture --- p.7Chapter 1.2.2.2 --- Weaver Architecture --- p.9Chapter 1.3 --- Image-rejection ratio --- p.10Chapter 1.4 --- Thesis Organization --- p.12Chapter CHAPTER 2 --- FUNDAMENTALS OF OSCILLATOR --- p.13Chapter 2.1 --- Basic Oscillator Theory --- p.13Chapter 2.2 --- Varactor --- p.15Chapter 2.3 --- Inductor --- p.17Chapter 2.4 --- Phase noise --- p.22Chapter 2.4.1 --- The Leeson ´ةs phase noise expression --- p.24Chapter 2.4.2 --- Linear model --- p.25Chapter 2.4.3 --- Linear Time-Variant phase noise model --- p.28Chapter CHAPTER 3 --- FULLY-INTEGRATED CMOS OSCILLATOR DESIGN --- p.31Chapter 3.1 --- Ring oscillator --- p.31Chapter 3.2 --- LC oscillator --- p.33Chapter 3.2.1 --- LC-tank resonator --- p.34Chapter 3.2.2 --- Negative transconductance --- p.36Chapter 3.3 --- Generation of quadrature phase signals --- p.39Chapter 3.4 --- Quadrature VCO topologies --- p.41Chapter 3.4.1 --- Parallel-coupled QVCO --- p.41Chapter 3.4.2 --- Series-coupled QVCO --- p.46Chapter 3.4.3 --- QVCO with Back-gate Coupling --- p.47Chapter 3.4.4 --- QVCO using superharmonic coupling --- p.49Chapter 3.5 --- Novel QVCO using back-gate superharmonic coupling --- p.52Chapter 3.5.1 --- Tuning range --- p.54Chapter 3.5.2 --- Negative gm --- p.55Chapter 3.5.3 --- Phase noise calculation --- p.56Chapter 3.5.4 --- Coupling coefficient --- p.57Chapter 3.5.5 --- Low-voltage and low-power design --- p.59Chapter 3.5.6 --- Layout Consideration --- p.61Chapter 3.5.6.1 --- Symmetrical Layout and parasitics --- p.61Chapter 3.5.6.2 --- Metal width and number of vias --- p.63Chapter 3.5.6.3 --- Substrate contact and guard ring --- p.63Chapter 3.5.7 --- Simulation Results --- p.65Chapter 3.5.7.1 --- Frequency and output power --- p.65Chapter 3.5.7.2 --- Quadrature signal generation --- p.67Chapter 3.5.7.3 --- Tuning range --- p.67Chapter 3.5.7.4 --- Power consumption --- p.68Chapter 3.5.7.5 --- Phase noise --- p.69Chapter 3.6 --- Polyphase filter and Single-sideband mixer design --- p.70Chapter 3.6.1 --- Polyphase filter --- p.72Chapter 3.6.2 --- Layout Consideration --- p.74Chapter 3.6.3 --- Simulation results --- p.76Chapter 3.7 --- Comparison with parallel-coupled QVCO --- p.78Chapter CHAPTER 4 --- EXPERIMENTAL RESULTS --- p.80Chapter 4.1 --- Test Fixture --- p.82Chapter 4.2 --- Measurement set-up --- p.84Chapter 4.3 --- Measurement results --- p.86Chapter 4.3.1 --- Proposed QVCO using back-gate superharmonic coupling --- p.86Chapter 4.3.1.1 --- Output Spectrum --- p.86Chapter 4.3.1.2 --- Tuning range --- p.87Chapter 4.3.1.3 --- Phase noise --- p.88Chapter 4.3.1.4 --- Power consumption --- p.88Chapter 4.3.1.5 --- Image-rejection ratio --- p.89Chapter 4.3.2 --- Parallel-coupled QVCO --- p.90Chapter 4.3.2.1 --- Output spectrum --- p.90Chapter 4.3.2.2 --- Power consumption --- p.90Chapter 4.3.2.3 --- Tuning range --- p.91Chapter 4.3.2.4 --- Phase noise --- p.92Chapter 4.3.3 --- Comparison between proposed and parallel-coupled QVCO --- p.93Chapter CHAPTER 5 --- CONCLUSIONS --- p.95Chapter 5.1 --- Conclusions --- p.95Chapter 5.2 --- Future work --- p.97REFERENCES --- p.9

Integrated radio frequency synthetizers for wireless applications

This thesis consists of six publications and an overview of the research topic, which is also a summary of the work. The research described in this thesis concentrates on the design of phase-locked loop radio frequency synthesizers for wireless applications. In particular, the focus is on the implementation of the prescaler, the phase detector, and the chargepump. This work reviews the requirements set for the frequency synthesizer by the wireless standards, and how these requirements are derived from the system specifications. These requirements apply to both integer-N and fractional-N synthesizers. The work also introduces the special considerations related to the design of fractional-N phase-locked loops. Finally, implementation alternatives for the different building blocks of the synthesizer are reviewed. The presented work introduces new topologies for the phase detector and the chargepump, and improved topologies for high speed CMOS prescalers. The experimental results show that the presented topologies can be successfully used in both integer-N and fractional-N synthesizers with state-of-the-art performance. The last part of this work discusses the additional considerations that surface when the synthesizer is integrated into a larger system chip. It is shown experimentally that the synthesizer can be successfully integrated into a complex transceiver IC without sacrificing the performance of the synthesizer or the transceiver.reviewe

Receiver Front-Ends in CMOS with Ultra-Low Power Consumption

Historically, research on radio communication has focused on improving range and data rate. In the last decade, however, there has been an increasing demand for low power and low cost radios that can provide connectivity with small devices around us. They should be able to offer basic connectivity with a power consumption low enough to function extended periods of time on a single battery charge, or even energy scavenged from the surroundings. This work is focused on the design of ultra-low power receiver front-ends intended for a receiver operating in the 2.4GHz ISM band, having an active power consumption of 1mW and chip area of 1mm². Low power consumption and small size make it hard to achieve good sensitivity and tolerance to interference. This thesis starts with an introduction to the overall receiver specifications, low power radio and radio standards, front-end and LO generation architectures and building blocks, followed by the four included papers. Paper I demonstrates an inductorless front-end operating at 915MHz, including a frequency divider for quadrature LO generation. An LO generator operating at 2.4GHz is shown in Paper II, enabling a front-end operating above 2GHz. Papers III and IV contain circuits with combined front-end and LO generator operating at or above the full 2.45GHz target frequency. They use VCO and frequency divider topologies that offer efficient operation and low quadrature error. An efficient passive-mixer design with improved suppression of interference, enables an LNA-less design in Paper IV capable of operating without a SAW-filter

Transceiver architectures and sub-mW fast frequency-hopping synthesizers for ultra-low power WSNs

Wireless sensor networks (WSN) have the potential to become the third wireless revolution after wireless voice networks in the 80s and wireless data networks in the late 90s. This revolution will finally connect together the physical world of the human and the virtual world of the electronic devices. Though in the recent years large progress in power consumption reduction has been made in the wireless arena in order to increase the battery life, this is still not enough to achieve a wide adoption of this technology. Indeed, while nowadays consumers are used to charge batteries in laptops, mobile phones and other high-tech products, this operation becomes infeasible when scaled up to large industrial, enterprise or home networks composed of thousands of wireless nodes. Wireless sensor networks come as a new way to connect electronic equipments reducing, in this way, the costs associated with the installation and maintenance of large wired networks. To accomplish this task, it is necessary to reduce the energy consumption of the wireless node to a point where energy harvesting becomes feasible and the node energy autonomy exceeds the life time of the wireless node itself. This thesis focuses on the radio design, which is the backbone of any wireless node. A common approach to radio design for WSNs is to start from a very simple radio (like an RFID) adding more functionalities up to the point in which the power budget is reached. In this way, the robustness of the wireless link is traded off for power reducing the range of applications that can draw benefit form a WSN. In this thesis, we propose a novel approach to the radio design for WSNs. We started from a proven architecture like Bluetooth, and progressively we removed all the functionalities that are not required for WSNs. The robustness of the wireless link is guaranteed by using a fast frequency hopping spread spectrum technique while the power budget is achieved by optimizing the radio architecture and the frequency hopping synthesizer Two different radio architectures and a novel fast frequency hopping synthesizer are proposed that cover the large space of applications for WSNs. The two architectures make use of the peculiarities of each scenario and, together with a novel fast frequency hopping synthesizer, proved that spread spectrum techniques can be used also in severely power constrained scenarios like WSNs. This solution opens a new window toward a radio design, which ultimately trades off flexibility, rather than robustness, for power consumption. In this way, we broadened the range of applications for WSNs to areas in which security and reliability of the communication link are mandatory

Low-power CMOS front-ends for wireless personal area networks

The potential of implementing subthreshold radio frequency circuits in deep sub-micron CMOS technology was investigated for developing low-power front-ends for wireless personal area network (WPAN) applications. It was found that the higher transconductance to bias current ratio in weak inversion could be exploited in developing low-power wireless front-ends, if circuit techniques are employed to mitigate the higher device noise in subthreshold region. The first fully integrated subthreshold low noise amplifier was demonstrated in the GHz frequency range requiring only 260 μW of power consumption. Novel subthreshold variable gain stages and down-conversion mixers were developed. A 2.4 GHz receiver, consuming 540 μW of power, was implemented using a new subthreshold mixer by replacing the conventional active low noise amplifier by a series-resonant passive network that provides both input matching and voltage amplification. The first fully monolithic subthreshold CMOS receiver was also implemented with integrated subthreshold quadrature LO (Local Oscillator) chain for 2.4 GHz WPAN applications. Subthreshold operation, passive voltage amplification, and various low-power circuit techniques such as current reuse, stacking, and differential cross coupling were combined to lower the total power consumption to 2.6 mW. Extremely compact resistive feedback CMOS low noise amplifiers were presented as a cost-effective alternative to narrow band LNAs using high-Q inductors. Techniques to improve linearity and reduce power consumption were presented. The combination of high linearity, low noise figure, high broadband gain, extremely small die area and low power consumption made the proposed LNA architecture a compelling choice for many wireless applications.Ph.D.Committee Chair: Laskar, Joy; Committee Member: Chakraborty, Sudipto; Committee Member: Chang, Jae Joon; Committee Member: Divan, Deepakraj; Committee Member: Kornegay, Kevin; Committee Member: Tentzeris, Emmanoui

Theory of phaselock techniques as applied to aerospace transponders

Phaselock techniques as applied to aerospace transponder