International Technology Roadmap for Semiconductors 2003の要求清浄度について － シリコンウエハ表面と雰囲気環境に要求される清浄度, 分析方法の現状について －

Frequencies from 100 GHz to 3 THz are promising bands for the next generation of wireless communication systems because of the wide swaths of unused and unexplored spectrum. These frequencies also offer the potential for revolutionary applications that will be made possible by new thinking, and advances in devices, circuits, software, signal processing, and systems. This paper describes many of the technical challenges and opportunities for wireless communication and sensing applications above 100 GHz, and presents a number of promising discoveries, novel approaches, and recent results that will aid in the development and implementation of the sixth generation (6G) of wireless networks, and beyond. This paper shows recent regulatory and standard body rulings that are anticipating wireless products and services above 100 GHz and illustrates the viability of wireless cognition, hyper-accurate position location, sensing, and imaging. This paper also presents approaches and results that show how long distance mobile communications will be supported to above 800 GHz since the antenna gains are able to overcome air-induced attenuation, and present methods that reduce the computational complexity and simplify the signal processing used in adaptive antenna arrays, by exploiting the Special Theory of Relativity to create a cone of silence in over-sampled antenna arrays that improve performance for digital phased array antennas. Also, new results that give insights into power efficient beam steering algorithms, and new propagation and partition loss models above 100 GHz are given, and promising imaging, array processing, and position location results are presented. The implementation of spatial consistency at THz frequencies, an important component of channel modeling that considers minute changes and correlations over space, is also discussed. This paper offers the first in-depth look at the vast applications of THz wireless products and applications and provides approaches for how to reduce power and increase performance across several problem domains, giving early evidence that THz techniques are compelling and available for future wireless communications.

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Wireless Communications and Applications Above 100 GHz: Opportunities and Challenges for 6G and Beyond

The market for driver assistance systems based on millimeter-wave radar sensor technology is gaining momentum. In the near future, the full range of newly introduced car models will be equipped with radar based systems which leads to high volume production with low cost potential. This paper provides background and an overview of the state of the art of millimeter-wave technology for automotive radar applications, including two actual silicon based fully integrated radar chips. Several advanced packaging concepts and antenna systems are presented and discussed in detail. Finally measurement results of the fully integrated radar front ends are shown.

Millimeter-Wave Technology for Automotive Radar Sensors in the 77 GHz Frequency Band

Introduction to Electromagnetic Compatibility

Automotive radars, along with other sensors such as lidar, (which stands for "light detection and ranging"), ultrasound, and cameras, form the backbone of self-driving cars and advanced driver assistant systems (ADASs). These technological advancements are enabled by extremely complex systems with a long signal processing path from radars/sensors to the controller. Automotive radar systems are responsible for the detection of objects and obstacles, their position, and speed relative to the vehicle. The development of signal processing techniques along with progress in the millimeter-wave (mm-wave) semiconductor technology plays a key role in automotive radar systems. Various signal processing techniques have been developed to provide better resolution and estimation performance in all measurement dimensions: range, azimuth-elevation angles, and velocity of the targets surrounding the vehicles. This article summarizes various aspects of automotive radar signal processing techniques, including waveform design, possible radar architectures, estimation algorithms, implementation complexity-resolution trade off, and adaptive processing for complex environments, as well as unique problems associated with automotive radars such as pedestrian detection. We believe that this review article will combine the several contributions scattered in the literature to serve as a primary starting point to new researchers and to give a bird's-eye view to the existing research community.

Automotive Radars: A review of signal processing techniques

This paper describes the first fundamental frequency single-chip transceiver operating at -band. The low-IF monostatic transceiver integrates on a single chip two 120-GHz voltage-controlled oscillators (VCOs), a 120-GHz divide-by-64 chain, two in-phase/quadrature (IQ) receivers with phase-calibration circuitry, a variable gain transmit amplifier, an antenna directional coupler, a patch antenna, bias circuitry, a transmit power detector, and a temperature sensor. A quartz antenna resonator with 6-dBi gain and simulated 50% efficiency is placed directly above the on-chip patch to transmit and receive the 120-GHz signals. The circuit with the above-integrated-circuit antenna occupies an area of 2.2 mm 2.6 mm, consumes 900 mW from 1.2- and 1.8-V supplies, and was wire-bonded in an open-lid 7 mm 7 mm quad-flat no-leads package. Some transceiver performance parameters were characterized on the packaged chip, mounted on an evaluation board, while others, such as receiver noise figure and VCO phase noise at the 120-GHz output were measured on circuit breakouts. The AMOS-varactor VCOs have a typical phase noise of at 1-MHz offset and a tuning range of 115.2-123.9 GHz. The receiver gain and the transmitter output power are each adjustable over a range of 15 dB with a maximum transmitter output power of 3.6 dBm. The receiver IQ phase difference, measured at the IF outputs of the packaged transceiver, is adjustable from 70° to 110°, while the amplitude imbalance remains less than 1 dB. The receiver breakout gain and double-sideband noise figure are 10.5-13 and 10.5-11.5 dB, respectively, with an input compression point of . Several experiments were conducted through the air over distances of up to 2.1 m with a focusing lens placed above the packaged chip.

A Fundamental Frequency 120-GHz SiGe BiCMOS Distance Sensor With Integrated Antenna

In the last few years automotive radar has been transformed from being a niche sensor to becoming standard even in middle-class cars. With Euro-NCAP ratings now requiring automated braking and pedestrian safety functionality, radar is often identified as the best suited sensor for this purpose. Additionally, future automated driving will require detailed and highly reliable information on the environment and surrounding street traffic. This requires radar sensors to provide more detailed information about the environment, foremost in the spatial domain. Automotive radar has always benefited significantly from technological advances, especially in semiconductor technology and packaging, allowing a better performance and much more functionality in the radar frontend. A second key area is the antenna system, where new concepts to acquire more information about signals reflected from the environment can significantly improve resolution and detection performance.

Driving towards 2020: Automotive radar technology trends

A novel beam-steering approach is presented based on the superposition of two squinted antenna beams. The two antenna beams are realized by exciting the opposite feeds of a dual-fed array antenna. A change in phase difference and amplitude ratio between the input signals, possibly using only one phase shifter and one variable gain amplifier, steers the main beam in different directions. Additionally, sum and difference patterns can be obtained using this concept, allowing for a monopulse operation with a broad peak or a deep null at broadside. Using this approach, beam nulls can also be steered toward interference directions, while keeping the shape and direction of the main beam unchanged. To verify the concept, a 77-GHz demonstrator using a linear patch array antenna and monolithic microwave integrated circuit in-phase/quadrature modulators has been designed and fabricated. The measurement results show a beam-scanning range of 16 °, well in accord with the simulation results.

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A Novel Millimeter-Wave Dual-Fed Phased Array for Beam Steering

In this paper, an incoherent radar network based on integrated radar sensors is presented. It consists of radar sensor nodes with independently generated frequency-modulated continuous wave-modulated transmit signals, performing both monostatic and bistatic distance measurements. An architecture to operate such a cooperative bistatic network is introduced and an optimal parameterization of the system is presented. Several nonidealities of frequency synthesizers, that are important for such cooperative radar networks, are discussed and their influence on system performance is evaluated. A prototype of the cooperative bistatic network has been realized using highly integrated radar sensors at 122 GHz. Radar measurements using the prototype prove the feasibility and potential of the network approach. The complete signal processing chain is presented, including an adapted multilateration algorithm for target position estimation using all measured distances.

Jurgen Hasch

Papers

Millimeter-Wave Technology for Automotive Radar Sensors in the 77 GHz Frequency Band

A Fundamental Frequency 120-GHz SiGe BiCMOS Distance Sensor With Integrated Antenna

Driving towards 2020: Automotive radar technology trends

A Novel Millimeter-Wave Dual-Fed Phased Array for Beam Steering

A Cooperative MIMO Radar Network Using Highly Integrated FMCW Radar Sensors