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Unit IV. Programming light on a chip …………………………………….. 11

Unit IX. Can radar replace stethoscopes? …………………………………. 24 Unit X. Quantum radar will expose stealth aircraft ………………………. 27

Список рекомендуемых источников…………………………………….. 29 Appendix…………………………………………………………………... 30

1.Useful phrases for retelling articles and writing summaries …................ 30

2.Answer keys …………………………………………………………….. 32

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Unit I. Balancing the beam: Thermomechanical micromachine detects terahertz radiation

1. Study the following words and expressions.

Electromagnetic spectrum – спектр электромагнитного излучения; terahertz region of the spectrum – терагерцовая область спектра.

2. Read and translate the text.

Radiation from many parts of the electromagnetic spectrum has been harnessed for extremely beneficial uses, in fields as diverse as medicine, imaging and photography, and astronomy. However, the terahertz (THz) region of the spectrum, situated between microwaves and infrared light, has been relatively underutilized owing to difficulties in generating such radiation artificially and in building devices to detect it.

In a breakthrough in the field of terahertz detection, researchers at the University of Tokyo and colleagues have created a thermomechanical device that can sense radiation in the terahertz region of the spectrum in a sensitive and rapid manner, without the need for intense cooling to cryogenic temperatures such as 270ºC. This device potentially opens up a range of new applications for THz technologies, such as THz cameras.

In this study, reported in the Journal of Applied Physics, the team made use of the heat generated by THz radiation in order to detect it. Specifically, they created a device featuring a tiny beam suspended across a gap, which they then coated with a resistive metal film [nickel-chromium (NiCr) in this case]. This metal film has the ability to absorb THz radiation, which in turn transfers heat to the beam as a whole. This increase in temperature causes the beam to expand very slightly, which can be detected as a change in the frequency at which the beam resonantly vibrates.

"Using our doubly clamped microelectromechanical beam made of gallium arsenide, we could effectively sense THz radiation at room temperature," corresponding author Kazuhiko Hirakawa says. "This structure is particularly effective as it can detect THz radiation very quickly, typically 100 times faster than other conventional room-temperature thermal THz sensors."

This new approach has a range of advantages over existing alternatives for the detection of THz radiation. The fact that it can function at room temperature without the need for cooling makes it suitable for a range of real-world

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applications. It is also extremely sensitive, detecting radiation that causes changes in temperature as small as one-millionth of a degree.

"Another advantage of this system is that it can be produced using standard methods for fabricating semiconductor devices, which would potentially allow its incorporation into mass-produced THz-based sensors and cameras," according to lead author Ya Zhang. "We hope that our work will lead to an explosion of interest and further innovation in this field."

3.Find the English equivalents of the following Russian expression in the text. Make up sentence of your own using them.

Использовать излучение, полезное применение, недостаточно широко использоваться, область применения, вырабатывать тепло, покрыть резистивной пленкой из металла, обычные сенсоры, всплеск интереса.

4.Answer the following questions.

1.What are the possible applications of radiation?

2.What device has been created by the researchers at The University of Tokyo?

3.What are the advantages of this device?

5.Retell the article using the phrases from Appendix.

6.Translate the following text into English.

Терагерцовое электромагнитное излучение – это электромагнитное излучение диапазона от 0.1 до 30 терагерц, занимающее во всем спектре место между длинноволновым инфракрасным светом и микроволновым излучением. В настоящее время терагерцовые волны начинают широко применяться в системах контроля и безопасности, промышленных установках, астрономических исследованиях, в науке и медицине, где они становятся более безопасной для людей заменой рен тгеновской техники. Интерес ученых к разработке компактных источников терагерцового излучения, которые можно использовать в портативной и переносной электронной аппаратуре, постоянно растет.

Unit II. Integrated 140 GHz FMCW Radar for Vital Sign Monitoring and Gesture Recognition

1. Study the following words and expressions:

Frequency-modulated continuous wave radar – РЛС непрерывного излучения с частотной модуляцией;

IC technology (Integrated circuit) – технология интегральных схем;

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carrier frequency – несущая частота;

intuitive application – очевидная область применения; carrier modulation – модуляция несущей частоты.

2. Read and translate the text.

An integrated, high performance, 140 GHz frequency-modulated continuous wave (FMCW) radar system enables the detection of minute motion, offering utility for various applications.

Since the introduction of the first radar systems in the early 1930s, radar technology has evolved significantly. During this time, researchers have reduced the size, power consumption and cost dramatically, while increasing resolution and enhancing the algorithmic computational capabilities. Development and advances in IC technology have enabled a class of low-power and short-range mmWave radars with carrier frequencies in the 30 to 300 GHz range (10 to 1 mm wavelength), adding to the mass of wireless applications pervading society. Today, radars are embedded in a number of cars, as parking aids or for safety, detecting pedestrians, other road users and objects at a few meters.

These high frequency radars with small form factors can be integrated almost invisibly in numerous devices, to enable a broad range of smart and intuitive applications, such as building security (e.g., people counting and intruder detection), remote health monitoring of automobile drivers, monitoring the vital signs of patients and gesture recognition for intuitive man-machine interaction. The number of use cases will imminently grow as radar systems offer finer range resolution, smaller footprint, higher energy efficiency and lower cost.

Although all radar systems follow the same basic principle, their various implementations determine the cost, size, power consumption and capability. Radars can differ by the frequency of the carrier (e.g., 2.4, 8, 60, 79, 140 GHz), bandwidth, type of carrier modulation (e.g., frequency or phase) and pulsed or continuous wave (CW). By necessity, small radars with high resolution operate at high carrier frequencies with wide bandwidth. As resolution is inversely proportional to bandwidth, radar systems operating above 100 GHz can offer very broadband operation, which enables fine range resolution. A Doppler shift is observed as a change in frequency of the wave reflected from a target, when the source and target are moving closer together or further apart. This shift can be measured more precisely at higher frequencies to provide a more exact determination of a target’s velocity.

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In time, data from multiple sensors – which may add LiDAR, hyperspectral imagers, infrared cameras and ultrasonic sensors to radar – will be merged on a common platform, each offering advantages and having limitations. Radar technology is an environmentally robust solution and can serve as an alternative to optical image sensors when privacy concerns or regulations prohibit using cameras. Supplementing the development of radar sensor technology, advances in physical pattern recognition are driving advanced machine learning techniques to classify objects or gestures using radar Doppler signatures.

3.Find the English equivalents of the following Russian expression in the text. Make up sentence of your own using them.

Позволять, развиваться, значительно сократить, потребление мощности, вычислительные способности, распространяться в обществе, встраиваться, неизбежно расти, определять стоимость, обратно пропорционально, точно измерить, иметь ограничения, устойчивый к воздействию окружающей среды.

4.Answer the following questions.

1.In what way has radar technology evolved over the time?

2.What are the possible applications of high frequency radars?

3.How do radars differ from each other?

5.Retell the article using the phrases from Appendix.

6.Translate the following text into English.

Радар представляет собой систему обнаружения объектов, которая использует радиоволны, чтобы определить удаление, угол или скорость объектов. Система РЛС состоит из передатчика, испускающего электромагнитные волны в радиоили микроволновом диапазоне, передающей антенны, приемной антенны (часто используется одна и та же антенна для передачи и приема) и приемника с процессором для определения свойств объекта (ов). Радиоволны (импульсного или непрерывного действия) передатчика отражаются от объекта и, возвращаясь к приемнику, приносят информацию о местоположении и скорости объекта. Индикация перемещения цели может подвергаться воздействию эффекта Доплера, которое может производить гашение сигнала при определенных радиальных скоростях, что ухудшает эффективность радара. Доплеровский сдвиг зависит от того, активной или пассивной является конфигурация радара. Активный

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радар передает сигнал, который отражается обратно к приемнику. Пассивный радар зависит от объекта, посылающего сигнал на приемник.

Unit III. 140 GHz FMCW Radar transceiver IC 1. Study the following words and expressions.

On-chip – встроенный в микросхему;

bulk CMOS technology – технология КМОП ИС на полупроводниковой подложке;

CMOS – complementary metal-oxide semiconductor – комплементарный металло-оксидный полупроводник;

sub-sampling – субдискретизация;

digital phase-locked loop – цифровая система фазовой автоподстройки частоты;

FMCW – frequency modulated continuous wave – непрерывное излучение с частотной модуляцией;

chirp generator – генератор импульсов с частотной линейной модуляцией;

DC offsets – смещение постоянной составляющей; CW – carrier wave – несущая волна;

PLL – phase-locked loop – система фазовой автоподстройки частоты.

2. Read and translate the text.

Targeting vital sign detection and gesture recognition, imec has developed a 140 GHz FMCW radar transceiver with on-chip antennas. The radar operates over a range from 0.15 to 10 m and has 11 mm range resolution, achieved with 13 GHz of RF bandwidth centered at 145 GHz. The transceiver IC is fabricated with a production 28 nm bulk CMOS technology, which enables a low-cost solution.

The main building block of the radar is an integrated transceiver featuring on-chip antennas and a sub-sampling digital phase-locked loop (PLL), which forms the FMCW chirp generator. Antennas integrated on the same chip couple with each other, resulting in leakage between the transmit (Tx) and receive (Rx) paths; however, the radar features on-chip leakage cancellation in the receiver to circumvent this effect, which can result in gain compression and DC offsets. The radar receiver measures the difference between the frequency of the reflected and transmitted RF chirps. This frequency difference is translated into the MHz range, making amplification, filtering and analog-to-digital conversion much easier than with other radar waveforms (e.g., phase-modulated CW).

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The PLL generates a frequency modulated CW signal, where the carrier frequency is modulated over a wide bandwidth using a linear sawtooth waveform. The repetition rate of the modulating sawtooth is known as the chirp rate. Imec has developed and characterized a 16 GHz, fast chirping PLL fabricated with a 28 nm bulk CMOS process. This PLL can operate both in a classical mode as well as a divider-less sub-sampling mode, offering flexibility and high performance. The PLL achieves a wide chirp bandwidth of 1.5 GHz in only a 30 μs chirp period, allowing fast sawtooth frequency modulation.

Multiple transceiver ICs were used to create a 2x2 MIMO radar, augmenting the range and speed detection capabilities of a single-input-single-output radar. MIMO increases the azimuth angular resolution, providing additional information to resolve target orientation.

In the MIMO configuration, a central 16 GHz chirp signal is distributed to multiple Tx inputs. The signal is up-converted to 144 GHz using a cascade of two frequency triplers, after which it is amplified and transmitted via the on-chip antennas. The radiated chirp is reflected by targets broadside to the antennas and captured by the on-chip receiver. The reflected signal is amplified in the receiver and compared with a replica of the initial chirp signal, using a mixer. The delay of the received signal, corresponding to the time-of-flight to the target and back, results in an instantaneous frequency offset compared to the reference chirp. The greater the distance to the target, the greater the relative frequency shift and the range of the target is obtained from the frequency of the down-converted signal. The analog output from the receiver is converted to a digital signal, enabling signal processing to extract the range and speed.

The transmitter is characterized by its effective isotropic radiated power (EIRP). For the integrated 140 GHz prototype, the measured EIRP is as high as 11 dBm and has a 3 dB bandwidth from 127 to 154 GHz. This is the highest recorded EIRP in D-Band for a single integrated transceiver compared to currently published state-of-the-art ICs. The receiver’s performance is characterized by its noise figure and conversion gain: 8 and 84 dB, respectively. The total power consumption of the radar transceiver IC is less than 500 mW.

For many applications, including gesture recognition, high angular resolution is needed to capture gestures in three dimensions. This can be accomplished with MIMO radar, as they transmit mutually orthogonal signals from multiple Tx antennas, which are then extracted from each of the Rx antennas. Imec

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has demonstrated a 1x4 virtual array with three transceiver ICs, including two transmitters and two receivers, resulting in a 2x2 MIMO assembly. The configuration is called “1x4 virtual” because the angular resolution corresponds to the resolution obtained by the four elements in a row. In this configuration, the central chirp signal is distributed to the separate transceiver chips on a PCB. Using the super-resolution MUSIC algorithm, a fine angular resolution of 7.5 degrees is achieved with a complete MIMO radar form factor of only a few square centimeters.

3.Find the English equivalents of the following Russian expression in the text. Make up sentence of your own using them.

Разрешающая способность, бюджетное решение, структурный элемент, приводить к, частота повторений, мгновенная частота, современный, потребление энергии, угловое разрешение.

4.Answer the following questions.

1.In what way is the new radar highlighted in the article different from other

radars?

2.What are its features?

3.What does MIMO configuration imply?

5.Retell the article using the phrases from Appendix.

6.Translate the following text into English.

Радар FMCW представляет собой частотно модулированный радар непрерывной волны. Немодулированные радары непрерывной волны имеют недостаток, заключающийся в том, что они не могут измерить расстояние, поскольку отсутствует привязка ко времени. Такая привязка ко времени для измерения расстояния неподвижных объектов может генерироваться посредством частотной модуляции. С помощью этого способа формируется сигнал, который непрерывно меняет частоту. Периодическая линейная частота, изменяющаяся в сторону увеличения и уменьшения, используется для ограничения частотного диапазона и упрощения процесса оценки сигнала. Коэффициент степени изменения df/dt не меняется. Полученный сигнал имеет задержку, как и импульсный радиолокатор, поэтому частота различия пропорциональна дистанции.

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