There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

This tutorial presents an overview of the technological advances in millimeter-wave (mm-wave) circuit components, antennas, and propagation that will soon allow 60-GHz transceivers to provide multigigabit per second (multi-Gb/s) wireless communication data transfers in the consumer marketplace. Our goal is to help engineers understand the convergence of communications, circuits, and antennas, as the emerging world of subterahertz and terahertz wireless communications will require understanding at the intersections of these areas. This paper covers trends and recent accomplishments in a wide range of circuits and systems topics that must be understood to create massively broadband wireless communication systems of the future. In this paper, we present some evolving applications of massively broadband wireless communications, and use tables and graphs to show research progress from the literature on various radio system components, including on-chip and in-package antennas, radio-frequency (RF) power amplifiers (PAs), low-noise amplifiers (LNAs), voltage-controlled oscillators (VCOs), mixers, and analog-to-digital converters (ADCs). We focus primarily on silicon-based technologies, as these provide the best means of implementing very low-cost, highly integrated 60-GHz mm-wave circuits. In addition, the paper illuminates characterization techniques that are required to competently design and fabricate mm-wave devices in silicon, and illustrates effects of the 60-GHz RF propagation channel for both in-building and outdoor use. The paper concludes with an overview of the standardization and commercialization efforts for 60-GHz multi-Gb/s devices, and presents a novel way to compare the data rate versus power efficiency for future broadband devices.

http://faculty.poly.edu/~tsr/wp-content/uploads/publications/abstract17.pdf

State of the Art in 60-GHz Integrated Circuits and Systems for Wireless Communications

Multiple GHz of internationally available, unlicensed spectrum surrounding the 60 GHz carrier frequency has the ability to accommodate high-throughput wireless communications. While the size and availability of this free spectrum make it very attractive for wireless applications, 60 GHz implementations must overcome many challenges. For example, the high attenuation and directional nature of the 60 GHz wireless channel as well as limited gain amplifiers and excessive phase noise in 60 GHz transceivers are explicit implementation difficulties. The challenges associated with this channel motivate commercial deployment of short-range wireless local area networks, wireless personal area networks, and vehicular networks. In this paper we detail design tradeoffs for algorithms in the 60 GHz physical layer including modulation, equalization, and space-time processing. The discussion is enhanced by considering the limitations in circuit design, characteristics of the effective wireless channel (including antennas), and performance requirements to support current and next generation 60 GHz wireless communication applications.

60 GHz wireless communications: emerging requirements and design recommendations

Advances in reflectarrays and array lenses with electronic beam-forming capabilities are enabling a host of new possibilities for these high-performance, low-cost antenna architectures. This paper reviews enabling technologies and topologies of reconfigurable reflectarray and array lens designs, and surveys a range of experimental implementations and achievements that have been made in this area in recent years. The paper describes the fundamental design approaches employed in realizing reconfigurable designs, and explores advanced capabilities of these nascent architectures, such as multi-band operation, polarization manipulation, frequency agility, and amplification. Finally, the paper concludes by discussing future challenges and possibilities for these antennas.

Reconfigurable Reflectarrays and Array Lenses for Dynamic Antenna Beam Control: A Review

Antenna-on-chip (AoC) and antenna-in-package (AiP) solutions are studied for highly integrated millimeter-wave (mmWave) devices in wireless communications. First, the background, regulations, standard, and applications of 60-GHz wireless communications are briefly introduced. Then, highly integrated 60-GHz radios are overviewed as a basis for the link budget analysis to derive the antenna gain requirement. Next, in order to have deep physical insight into the AoC solution, the silicon substrate's high permittivity and low resistivity effects on the AoC efficiency are examined. It is shown that the AoC solution has low efficiency, less than 12% due to large ohmic losses and surface waves, which requires the development of techniques to improve the AoC efficiency. After that, the AiP solution and associated challenges such as how to realize low-loss interconnection between the chip and antenna are addressed. It is shown that wire-bonding interconnects, although inferior to the flip-chip, are still feasible in the 60-GHz band if proper compensation schemes are utilized. An example of the AiP solution in a low-temperature cofired ceramic (LTCC) process is presented in the 60-GHz band showing an efficiency better than 90%. A major concern with both AoC and AiP solutions is electromagnetic interference (EMI), which is also discussed. Finally, the systems level pros and cons of both AoC and AiP solutions are highlighted from the electrical and economic perspectives for system designers.

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Antenna-on-Chip and Antenna-in-Package Solutions to Highly Integrated Millimeter-Wave Devices for Wireless Communications

We present the design and measurement results of millimeter-wave integrated circuits implemented in 65-nm baseline CMOS. Both active and passive test structures were measured. In addition, we present the design of an on-chip spiral balun and the transition from CPW to the balun and report transistor noise parameter measurement results at V-band. Finally, the design and measurement results of two amplifiers and a balanced resistive mixer are presented. The 40-GHz amplifier exhibits 14.3 dB of gain and the 1-dB output compression point is at +6-dBm power level using a 1.2 V supply with a compact chip area of 0.286 mm2. The 60-GHz amplifier achieves a measured noise figure of 5.6 dB at 60 GHz. The AM/AM and AM/PM results show a saturated output power of +7 dBm using a 1.2 V supply. In downconversion, the balanced resistive mixer achieves 12.5 dB of conversion loss and +5 dBm of 1-dB input compression point. In upconversion, the measured conversion loss was 13.5 dB with -19 dBm of 1-dB output compression point.

Millimeter-Wave Integrated Circuits in 65-nm CMOS

We present two W-band amplifiers, one implemented using conventional coplanar waveguides and unshielded passives and the other using slow-wave shielded waveguides and passives, realized in a 65-nm baseline CMOS technology. The measured results suggest that the slow-wave shielding of the passives is useful in achieving high performance and high frequency of operation. Our custom layout slotted plate capacitor employing slow-wave shield has low parasitic series resistance. Furthermore, as the substrate losses are minimal the modeling becomes more accurate. The measured based amplifier achieves +10 dBm output power at 100 GHz with a 1.2 V supply and 70 mA total DC-current consumption. The noise figure and gain at 100 GHz are 7.5 dB and 13 dB, respectively. The chip size of the implemented slow-wave amplifier is 0.33 mm2.

W-Band CMOS Amplifiers Achieving $+$ 10 dBm Saturated Output Power and 7.5 dB NF

This paper validates a design and modeling methodology of coupled slow-wave waveguides (CS-CPW) by presenting a D-band CMOS low-noise amplifier (LNA) that utilizes the CS-CPW for impedance matching. The robustness and feasibility of using the CS-CPW as a matching element in wideband millimeter-wave (mm-wave) silicon circuit designs are studied. Furthermore, the key design details of a mm-wave LNA are discussed. The designed monolithic microwave integrated circuit amplifier has a gain greater than 10 dB from 135 to 170 GHz with a peak gain of 15.7 dB at 160 GHz. The amplifier has a measured noise figure of 8.5 dB from 135 to 170 GHz, and an output-referred 1-dB compression point of −16.5 dBm at 160 GHz. The total power consumption of the amplifier is 32 mW.

/pdf/design-of-a-d-band-cmos-amplifier-utilizing-coupled-slow-1d85rxz0ec.pdf

Design of a D-Band CMOS Amplifier Utilizing Coupled Slow-Wave Coplanar Waveguides

We report two resistive mixers, i.e., a balanced and a balanced image-rejection (IR) mixer for the 60-GHz frequency range. A compact and wide-band method for the local-oscillator (LO) power division is presented. The 56-GHz LO signal, which propagates in a coplanar-waveguide mode, is divided in between the lines of two spiral baluns. Consequently, a smooth and compact transition from even-to-odd propagation mode and an in-phase power division for two singly balanced unit mixers is achieved. As a result, the developed IR mixer occupies only 1.41mm/sup 2/ of chip area. The balanced design achieved 11.5 dB of conversion loss from 57 to 67 GHz with a fixed IF of 5.3 GHz. The corresponding LO suppression was better than 34 dB with 8 dBm of LO power. The IR mixer achieved better than 19 dB of IR ratio and better than 36 dB of LO suppression for an RF frequency from 57 to 66 GHz. The corresponding conversion loss varies from 13 to 16 dB. The measured 1-dB compression point of the IR mixer was at a -13-dBm output power level and the third-order intercept point was at a 4-dBm level.

Resistive HEMT mixers for 60-GHz broad-band telecommunication

We report a wideband resistive mixer fabricated in 65-nm CMOS for 60-GHz frequency range. The local oscillator signal balancing is implemented with an on-chip spiral balun. The broadband response of the balun enables wideband local oscillator tuning range. The mixer topology is suitable for both up- and downconversion. We present the on-wafer measurement results in both of these mixing modes. In downconversion, the mixer achieved 12.5 dB of conversion loss and +5 dBm of 1-dB input compression point. In upconversion, the measured conversion loss was 13.5 dB with -19 dBm of 1-dB output compression point. The local oscillator suppression was better than 34 dB for an LO frequency from 51 to 62 GHz. The size of the mixer including pads is 0.47 mm2.

Mikko Varonen

Papers

Millimeter-Wave Integrated Circuits in 65-nm CMOS

W-Band CMOS Amplifiers Achieving $+$ 10 dBm Saturated Output Power and 7.5 dB NF

Design of a D-Band CMOS Amplifier Utilizing Coupled Slow-Wave Coplanar Waveguides

Resistive HEMT mixers for 60-GHz broad-band telecommunication

V-band balanced resistive mixer in 65-nm CMOS