Разработка компактных генераторных комплексов на основе клинотронов терагерцевого диапазона в ИРЭ им. А.Я. Усикова НАН Украины

Предмет и цель работы. В статье изложены результаты, достигнутые в последнее время в отделе вакуумной электроники Института радиофизики и электроники им. А.Я. Усикова Национальной академии наук Украины при создании компактных комплексов для генерации электромагнитного излучения в терагерцевом (ТГц) диапазоне частот. Данные комплексы, использующие клинотроны в качестве генератора электромагнитных колебаний, предназначены для проведения экспериментальных исследований в области спектроскопии ядерного магнитного резонанса с применением техники динамической поляризации ядер.Предмет і мета роботи. У статті викладено результати, які були досягнуті останнім часом у відділі вакуумної електроніки Інституту радіофізики та електроніки ім. О.Я. Усикова Національної академії наук України при створенні компактних комплексів для генерації електромагнітного випромінювання в терагерцовому (ТГц) діапазоні частот. Ці комплекси використовують клинотрони як генератори електромагнітних коливань і призначені для проведення експериментальних досліджень в області спектроскопії ядерного магнітного резонансу із застосуванням техніки динамічної поляризації ядер.Subject and purpose. This paper deals with the results recently obtained in Vacuum Electronics Department of O. Ya. Usikov Institute for Radiophysics and Electronics of National Academy of Sciences of Ukraine during the development of compact complexes for generation of electromagnetic radiation in the terahertz frequency range. These complexes with clinotrons as electromagnetic oscillators are intended for carrying out experimental researches in the field of nuclear magnetic resonance spectroscopy using the dynamic nuclear polarization technique

Demonstration of fully integrated parity-time-symmetric electronics

Harnessing parity-time (PT) symmetry with balanced gain and loss profiles has created a variety of opportunities in electronics from wireless energy transfer to telemetry sensing and topological defect engineering. However, existing implementations often employ ad-hoc approaches at low operating frequencies and are unable to accommodate large-scale integration. Here, we report a fully integrated realization of PT-symmetry in a standard complementary metal-oxide-semiconductor technology. Our work demonstrates salient PT-symmetry features such as phase transition as well as the ability to manipulate broadband microwave generation and propagation beyond the limitations encountered by exiting schemes. The system shows 2.1 times bandwidth and 30 percentage noise reduction compared to conventional microwave generation in oscillatory mode and displays large non-reciprocal microwave transport from 2.75 to 3.10 gigahertz in non-oscillatory mode due to enhanced nonlinearities. This approach could enrich integrated circuit (IC) design methodology beyond well-established performance limits and enable the use of scalable IC technology to study topological effects in high-dimensional non-Hermitian systems.Comment: 52 pages (16 pages Main Text, 28 pages Supplementary Materials, 4 pages reference), 27 figures (4 figures Main Text, 23 figures Supplementary Materials), 93 references (50 references Main Text, 43 references Supplementary Materials

Single chip dynamic nuclear polarization microsystem

The integration on a single chip of the sensitivity-relevant electronics of nuclear magnetic resonance (NMR) and electron spin resonance (ESR) spectrometers is a promising approach to improve the limit of detection, especially for samples in the nanoliter and subnanoliter range. Here we demonstrate the co-integration on a single silicon chip of the front-end electronics of an NMR and an ESR detector. The excitation/detection planar spiral microcoils of the NMR and ESR detectors are concentric and interrogate the same sample volume. This combination of sensors allows to perform dynamic nuclear polarization (DNP) experiments using a single-chip integrated microsystem having an area of about 2 mm$^2$. In particular, we report $^1$H DNP-enhanced NMR experiments on liquid samples having a volume of about 1 nL performed at 10.7 GHz(ESR)/16 MHz(NMR). NMR enhancements as large as 50 are achieved on TEMPOL/H$_{2}$O solutions at room temperature. The use of state-of-the-art submicrometer integrated circuit technologies should allow the future extension of the single-chip DNP microsystem approach proposed here up the THz(ESR)/GHz(NMR) region, corresponding the strongest static magnetic fields currently available. Particularly interesting is the possibility to create arrays of such sensors for parallel DNP-enhanced NMR spectroscopy of nanoliter and subnanoliter samples

0.42 THz Transmitter with Dielectric Resonator Array Antenna

Off chip antennas do not occupy the expensive die area, as there is no limitation on their building material, and can be built in any size and shape to match the system requirements, which are all in contrast to on-chip antenna solutions. However, integration of off-chip antennas with Monolithic-Microwave-Integrated Chips (MMIC) and designing a low loss signal transmission from the signal source inside the MMIC to the antenna module is a major challenge and trade off. High resistivity silicon (HRS), is a low cost and extremely low loss material at sub-THz. It has become a prevailing material in fabrication of passive components for THz applications. This work makes use of HRS to build an off-chip Dielectric Resonator Antenna Array Module (DRAAM) to realize a highly efficient transmitter at 420 GHz. This work proposes novel techniques and solutions for design and integration of DRRAM with MMIC as the signal source. A proposed scalable 4×4 antenna structure aligns DRRAM on top of MMIC within 2 μm accuracy through an effortless assembly procedure. DRAAM shows 15.8 dB broadside gain and 0.85 efficiency. DRAs in the DRAAM are differentially excited through aperture coupling. Differential excitation not only inherently provides a mechanism to deliver more power to the antenna, it also removes the additional loss of extra balluns when outputs are differential inside MMIC. In addition, this work proposes a technique to double the radiation power from each DRA. Same radiating mode at 0.42 THz inside every DRA is excited through two separate differential sources. This approach provides an almost loss-less power combining mechanism inside DRA. Two 140_GHz oscillators followed by triplers drive each DRA in the demonstrated 4×4 antenna array. Each oscillator generates 7.2 dBm output power at 140 GHz with -83 dBc/Hz phase noise at 100 KHz and consumes 25 mW of power. An oscillator is followed by a tripler that generates -8 dBm output power at 420 GHz. Oscillator and tripler circuits use a smart layer stack up arrangement for their passive elements where the top metal layer of the die is grounded to comply with the planned integration arrangement. This work shows a novel circuit topology for exciting the antenna element which creates the feed element part of the tuned load for the tripler circuit, therefore eliminates the loss of the transition component, and maximizes the output power delivered to the antenna. The final structure is composed of 32 injection locked oscillators and drives a 4×4 DRAAM achieves 22.8 dBm EIRP

A 300-GHz Fundamental Oscillator in 65-nm CMOS Technology 1

Abstract—Magnetic feedback from a differential pair to the core of a cross-coupled oscillator reduces the effect of device losses, raising the oscillation frequency. Three prototypes using one-turn nested inductors and including on-chip downconversion mixers operate at 205 GHz, 240 GHz, and 300 GHz while drawing a power of 3.5 mW. A common approach to obtaining high oscillation frequencies is to employ “superharmonic ” oscillators, i.e., to “sift ” second or higher harmonics by techniques such as edge combining [1] or push-push action [2, 3]. By contrast, “fundamental ” oscillators operate at the first harmonic, offering two advantages: (a) they demonstrate the ability to achieve gain at the frequency of interest, paving the way for the design of other critical RF blocks such as amplifiers, mixers, and dividers; (b) they provide differential and even quadrature outputs, greatly simplifyingth

A built-in self-test technique for high speed analog-to-digital converters

Fundação para a Ciência e a Tecnologia (FCT) - PhD grant (SFRH/BD/62568/2009

CMOS Signal Synthesizers for Emerging RF-to-Optical Applications

The need for clean and powerful signal generation is ubiquitous, with applications spanning the spectrum from RF to mm-Wave, to into and beyond the terahertz-gap. RF applications including mobile telephony and microprocessors have effectively harnessed mixed-signal integration in CMOS to realize robust on-chip signal sources calibrated against adverse ambient conditions. Combined with low cost and high yield, the CMOS component of hand-held devices costs a few cents per part per million parts. This low cost, and integrated digital processing, make CMOS an attractive option for applications like high-resolution imaging and ranging, and the emerging 5-G communication space. RADAR techniques when expanded to optical frequencies can enable micrometers of resolution for 3D imaging. These applications, however, impose upto 100x more exacting specifications on power and spectral purity at much higher frequencies than conventional RF synthesizers. This generation of applications will present unconventional challenges for transistor technologies - whether it is to squeeze performance in the conventionally used spectrum, already wrung dry, or signal generation and system design in the relatively emptier mm-Wave to sub-mmWave spectrum, much of the latter falling in the ``Terahertz Gap". Indeed, transistor scaling and innovative device physics leading to new transistor topologies have yielded higher cut-off frequencies in CMOS, though still lagging well behind SiGe and III-V semiconductors. To avoid multimodule solutions with functionality partitioned across different technologies, CMOS must be pushed out of its comfort zone, and technology scaling has to have accompanying breakthroughs in design approaches not only at the system but also at the block level. In this thesis, while not targeting a specific application, we seek to formulate the obstacles in synthesizing high frequency, high power and low noise signals in CMOS and construct a coherent design methodology to address them. Based on this, three novel prototypes to overcome the limiting factors in each case are presented. The first half of this thesis deals with high frequency signal synthesis and power generation in CMOS. Outside the range of frequencies where the transistor has gain, frequency generation necessitates harmonic extraction either as harmonic oscillators or as frequency multipliers. We augment the traditional maximum oscillation frequency metric (fmax), which only accounts for transistor losses, with passive component loss to derive an effective fmax metric. We then present a methodology for building oscillators at this fmax, the Maximum Gain Ring Oscillator. Next, we explore generating large signals beyond fmax through harmonic extraction in multipliers. Applying concepts of waveform shaping, we demonstrate a Power Mixer that engineers transistor nonlinearity by manipulating the amplitudes and relative phase shifts of different device nodes to maximize performance at a specific harmonic beyond device cut-off. The second half proposes a new architecture for an ultra-low noise phase-locked loop (PLL), the Reference-Sampling PLL. In conventional PLLs, a noisy buffer converts the slow, low-noise sine-wave reference signal to a jittery square-wave clock against which the phase of a noisy voltage-controlled oscillator (VCO) is corrected. We eliminate this reference buffer, and measure phase error by sampling the reference sine-wave with the 50x faster VCO waveform already available on chip, and selecting the relevant sample with voltage proportional to phase error. By avoiding the N-squared multiplication of the high-power reference buffer noise, and directly using voltage-mode phase error to control the VCO, we eliminate several noisy components in the controlling loop for ultra-low integrated jitter for a given power consumption. Further, isolation of the VCO tank from any varying load, unlike other contemporary divider-less PLL architectures, results in an architecture with record performance in the low-noise and low-spur space. We conclude with work that brings together concepts developed for clean, high-power signal generation towards a hybrid CMOS-Optical approach to Frequency-Modulated Continuous-Wave (FMCW) Light-Detection-And-Ranging (LIDAR). Cost-effective tunable lasers are temperature-sensitive and have nonlinear tuning profiles, rendering precise frequency modulations or 'chirps' untenable. Locking them to an electronic reference through an electro-optic PLL, and electronically calibrating the control signal for nonlinearity and ambient sensitivity, can make such chirps possible. Approaches that build on the body of advances in electrical PLLs to control the performance, and ease the specification on the design of optical systems are proposed. Eventually, we seek to leverage the twin advantages of silicon-intensive integration and low-cost high-yield towards developing a single-chip solution that uses on-chip signal processing and phased arrays to generate precise and robust chirps for an electronically-steerable fine LIDAR beam