Millimeter Wave Silicon Based Ultra Wideband Automotive Radar Transceivers

Since the invention of the integrated circuit, the semiconductor industry has revolutionized the world in ways no one had ever anticipated. With the advent of silicon technologies, consumer electronics became light-weight and affordable and paved the way for an Information Communication-Entertainment age. While silicon almost completely replaced compound semiconductors from these markets, it has been unable to compete in areas with more stringent requirements due to technology limitations. One of these areas is automotive radar sensors, which will enable next-generation collision warning systems in automobiles. A low-cost implementation is absolutely essential for widespread use of these systems, which leads us to the subject of this dissertation--silicon-based solutions for automotive radars. This dissertation presents architectures and design techniques for mm-wave automotive radar transceivers. Several fully-integrated transceivers and receivers operating at 22-29 GHz and 77-81 GHz are demonstrated in both CMOS and SiGe BiCMOS technologies. Excellent performance is achieved indicating the suitability of silicon technologies for automotive radar sensors. The first CMOS 22-29-GHz pulse-radar receiver front-end for ultra-wideband radars is presented. The chip includes a low noise amplifier, I/Q mixers, quadrature voltage-controlled oscillators, pulse formers and variable-gain amplifiers. Fabricated in 0.18-um CMOS, the receiver achieves a conversion gain of 35 38.1 dB and a noise figure of 5.5 7.4 dB. Integration of multi-mode multi-band transceivers on a single chip will enable next-generation low-cost automotive radar sensors. Two highly-integrated silicon ICs are designed in a 0.18-um BiCMOS technology. These designs are also the first reported demonstrations of mm-wave circuits with high-speed digital circuits on the same chip. The first mm-wave dual-band frequency synthesizer and transceiver, operating in the 24-GHz and 77-GHz bands, are demonstrated. All circuits except the oscillators are shared between the two bands. A multi-functional injection-locked circuit is used after the oscillators to reconfigure the division ratio inside the phase-locked loop. The synthesizer is suitable for integration in automotive radar transceivers and heterodyne receivers for 94-GHz imaging applications. The transceiver chip includes a dual-band low noise amplifier, a shared downconversion chain, dual-band pulse formers, power amplifiers, a dual-band frequency synthesizer and a high-speed programmable baseband pulse generator. Radar functionality is demonstrated using loopback measurements.

One of the leading causes of automobile accidents is the slow reaction of the driver while responding to a hazardous situation. State-of-the-art wireless electronics can automate several driving functions, leading to significant reduction in human error and improvement in vehicle safety. With continuous transistor scaling, silicon fabrication technology now has the potential to substantially reduce the cost of automotive radar sensors. This book bridges an existing gap between information available on dependable system/architecture design and circuit design. It provides the background of the field and detailed description of recent research and development of silicon-based radar sensors. System-level requirements and circuit topologies for radar transceivers are described in detail. Holistic approaches towards designing radar sensors are validated with several examples of highly-integrated radar ICs in silicon technologies. Circuit techniques to design millimeter-wave circuits in silicon technologies are discussed in depth.

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.

One of the leading causes of automobile accidents is the slow reaction of the driver while responding to a hazardous situation. State-of-the-art wireless electronics can automate several driving functions, leading to significant reduction in human error and improvement in vehicle safety. With continuous transistor scaling, silicon fabrication technology now has the potential to substantially reduce the cost of automotive radar sensors. This book bridges an existing gap between information available on dependable system/architecture design and circuit design. It provides the background of the field and detailed description of recent research and development of silicon-based radar sensors. System-level requirements and circuit topologies for radar transceivers are described in detail. Holistic approaches towards designing radar sensors are validated with several examples of highly-integrated radar ICs in silicon technologies. Circuit techniques to design millimeter-wave circuits in silicon technologies are discussed in depth.

Silicon-based integrated circuits used in the wireless technology have a great impact on our world. Moreover, such trend is continuing with ever-decreasing size of transistors. High speed wireless communication links are expected to become popular within most mobile devices in the next few years. On the other side, millimeter-wave (MMW) frequency has always been the terrain dominated by III-V compound semiconductor technology. However, the cost and low manufacturing yield of such systems prevent its commercialized use for new exciting applications, such as automotive intelligent system and imaging for public security and medical application. As the technology scaling in silicon, the increasing process ft and higher level of integration are promising to build lower cost, smaller sized MMW systems. This dissertation is following the goal to design and implement several prototype silicon-based integrated circuits at different technology nodes to address the key challenges faced by silicon both in circuit- and system-levels, therefore pave the path towards the fully-integrated systems for those emerging applications. A carrier-less RF-correlation-based impulse radio ultra-wideband (IR-UWB) transceiver front-end designed in 130nm CMOS process is presented. Timing synchronization and coherent demodulation are implemented directly in the RF domain. In order to solve the extremely large dynamic requirement of delay for RF synchronization, a template-based delay generation scheme is proposed and a 25ps timing resolution is achieved with a delay range of 500ps by a two-step timing synchronizer. The TRX achieves a maximum data rate of 2Gbps, while requiring only 51.5pJ/pulse in the TX mode and 72.9pJ/pulse in the RX mode. Finally a W-band receiver chipset for passive millimeter-wave imaging in a 65-nm standard CMOS technology is presented. The receiver design addresses the high 1/f noise issue in the advanced CMOS technology. An LO generation scheme is proposed to make it suitable for use in multi-pixel systems. In addition, the noise performance of the receiver is further improved by optimum biasing of transistors of the detector to achieve the highest responsivity and lowest NEP. The receiver chipset achieves a Dicke NETD of 0.52K, demonstrating the potential of CMOS for future low-cost portable passive imaging cameras.

Over the past decade, opportunities for utilizing the broadband spectrum available at millimeter-wave (mm-wave) frequencies has motivated research on both short and long-range, highly-integrated complementary metal oxide semiconductor (CMOS) transceivers. Prototype mm-wave CMOS transceivers have been demonstrated for application in high-speed data transfer (57-64 GHz), wireless back-haul (71-76 GHz), automotive radar (77GHz) and medical imaging (90 GHz) systems. However, in spite of promising results, large scale deployment of mm-wave CMOS transceivers in portable and hand-held electronics is currently hindered by front-end power-consumptions on the order of several watts. Moreover, as a first order approximation, power consumption is directly proportional to system bandwidth. Therefore, as the bandwidth requirements of systems increase, the challenge with on-chip power consumption will become increasingly difficult to solve. In this dissertation, techniques for optimizing the power and area of ultra-wideband millimeter-wave transceivers are described. This work resulted in the fabrication of three mm-wave integrated circuits (IC), all of which were realized in a 6-metal layer 40-nm CMOS process. The first IC is a multi-stage transformer-feedback based 11-to-13 GHz direct-conversion receiver. The device achieves a 16% fractional-bandwidth, a peak power-gain of 27.6dB, and noise-figure of 5.3dB while consuming 28.8mW from a 0.9V supply. Second, a compact 24-54GHz 2-stage bandpass distributed amplifier utilizing mirror-symmetric Norton transformations to reduce inductor component values allowing efficient layout to occupy an active area of 0.15mm2. The device has a 77% fractional-bandwidth, an overall gain of 6.3dB, a minimum in-band IIP3 of 11dBm, while consuming 34mA from a 1V supply. The third, and the IC which includes the most integration among the three, is an ultra-broadband single-element heterodyne receiver intended for use in low-power phased-array systems. The receiver maintains 17GHz of bandwidth from the mm-wave front end, through a high-IF stage, and to the baseband output. The device occupies 1.2mm2 and exploits properties of gain-equalized transformers throughout the signal path to achieve an overall 17GHz bandwidth 20dB gain with a flat in-band response, 7.8dB DSB NF, and a P[subscript-1dB] of -24dBm, while consuming 104mW off a 1.1V supply.

Build high-performance, energy-efficient circuits with this cutting-edge guide to designing, modeling, analysing, implementing and testing new mm-wave systems.

This book examines the critical differences between current and next-generation Si technologies (CMOS, BiCMOS and SiC) and technology platforms (e.g. system-on-chip) in mm-wave wireless applications. We provide a basic overview of the two technologies from a technical standpoint, followed by a review of the state-of-the-art of several key building blocks in wireless systems. The influences of system requirements on the choice of semiconductor technology are vital to understanding the merits of CMOS and BiCMOS devices – e.g., output power, battery life, adjacent channel interference, cost restrictions, and so forth. These requirements, in turn, affect component-level design and performance metrics of oscillators, mixers, power and low-noise amplifiers, as well as phase-locked loops and data converters. Finally, the book offers a peek into the next generation of wireless technologies such as THz -band systems and future 6G applications.

The research activity carried out during this PhD consists on the design of radio- frequency integrated circuits, for ultra-wideband (UWB) and millimeter-wave sys- tems, and covers the following topics: (i) radio-frequency integrated circuits for low-power transceivers for wireless local networks; (ii) fully integrated UWB radar for cardio-pulmonary monitoring in 90nm CMOS technology; (iii) 60-GHz low noise amplifer (LNA) in 65nm CMOS technology.

Historically, monolithic microwave integrated circuits (MMICs) have been designed using III-V semiconductor technologies, such as GaAs and InP. In recent years, the number of publications reporting silicon-based millimeter-wave (mm-wave) transmitter, receivers, and transceivers has grown steadily. For mm-wave applications including gigabit/s point-to-point links (57-64 GHz), automotive radar (77-81 GHz) and imaging (94 GHz) to reach mainstream market, the cost, size and power consumption of silicon-based solution has to be significantly below what is being achieved today using compound semiconductor technology. This dissertation focuses the effort of designing and implementing silicon-based solutions through circuit- and system-level innovation for applications in the W-band frequency band (75-110GHz), in particular, 94GHz passive imaging band. A W-band front-end receiver in 65nm CMOS based entirely on slow-wave CPW (SW-CPW) with frequency tripler as the LO is designed and measured. The receiver achieves a total gain of 35-dB, -3dB-BW of 12 GHz, a NF of 9-dB, a P1-dB of -40dBm, a low power consumption of 108mW under 1.2/0.8V. This front-end receiver chipset in conjuction with an analog back-end can be used to form a radiometer. Leveraging the work done in 65nm CMOS, the first integrated 2x2 focal-plane array (FPA) for passive imaging is implemented in a 0.18um SiGe BiCMOS process (fT/fmax=200/180GHz). The FPA incorporates four Dicke-type receivers. Each receiver employs a direct-conversion architecture consisting of an on-chip slot dipole antenna, an SPDT switch, a lower noise amplifier, a single-balanced mixer, an injection-locked frequency tripler (ILFT), a zero-IF variable gain amplifier, a power detector, an active bandpass filter and a synchronous demodulator. The LO signal is generated by a shared Ka-band PLL and distributed symmetrically to four ILFTs. This work demonstrates the highest level of integration of any silicon-based systems in the 94GHz imaging band. Finally, the main design bottleneck of any wireless transceiver system, the frequency synthesizer/phase-locked loop is investigated. Two monolithically integrated W-band frequency synthesizers are presented. Implemented in a 0.18um SiGe BiCMOS, both architectures incorporate the same 30.3-33.8GHz PLL core. One synthesizer uses an injection-locked frequency tripler (ILFT) with locking range of 92.8-98.1GHz and the other employ a harmonic-based frequency tripler (HBFT) with 3-dB bandwidth of 10.5GHz from 90.9-101.4GHz, respectively. The frequency synthesizer is suitable for integration in mm-wave phased array and multi-pixel systems such as W-band radar/imaging and 120GHz Gb/s communication.