Search

This paper reports investigations led on the combination of the refractive index and morphological dilation to enhance performances towards breast tumour margin delineation during conserving surgeries. The refractive index map of invasive ductal and lobular carcinomas were constructed from an inverse electromagnetic problem. Morphological dilation combined with refractive index thresholding was conducted to classify the tissue regions as malignant or benign. A histology routine was conducted to evaluate the performances of various dilation geometries associated with different thresholds. It was found that the combination of a wide structuring element and high refractive index was improving the correctness of tissue classification in comparison to other configurations or without dilation. The method reports a sensitivity of around 80% and a specificity of 82% for the best case. These results indicate that combining the fundamental optical properties of tissues denoted by their refractive index with morphological dilation may open routes to define supporting procedures during breast-conserving surgeries.

Measurement of total ionizing dose in a radiation field is efficiently carried out by ionisation chambers. The paper details the design of a mixed-signal ASIC for the front-end electronics of ionisation chambers. A single chip solution for ultra-low current measurement is designed by combining the current processing analog section realized using low leakage thick gate transistors and the data handling digital section implemented using fast thin gate transistors. The design succeeds in limiting the cross coupling between the two circuit domains using deep n-wells and guard rings. The ASIC fabricated in 130 nm technology attains a wide dynamic range of −7 fA to −20μA with maximum error in measurement less than ±4 %. The ASIC occupies an area of 3.52 mm 2 and has a total power consumption of 17.4 mW. The femtoampere range input leakage current of the ASIC contributed primarily by the ESD diodes was found to be varying exponentially with temperature. Dose rate measurements from 5 μ Sv/h to 7.4 Sv/h is demonstrated by interfacing the ASIC to an ionisation chamber.

Flexible energy harvesting devices fabricated in scalable thin-film processes are important components in the field of wearable electronics and the Internet of Things. We present a flexible rectenna based on a one-dimensional junction metal-insulator-graphene diode, which offers low-noise power detection at terahertz (THz) frequencies. The rectennas are fabricated on a flexible polyimide film in a scalable process by photolithography using graphene grown by chemical vapor deposition. A one-dimensional junction area reduces the junction capacitance and enables operation in the D-band (110 - 170 GHz). The rectenna on polyimide shows a maximum voltage responsivity of 80 V/W at 167 GHz in free space measurements and minimum noise equivalent power of 80 pW/$\sqrt{\text{Hz}}$., Comment: 20 pages, 4 figures, 1 table

The performance of terahertz (THz) dispersive spectroscopes is limited in spectral resolution and frequency accuracy due to a finite pixel count. This paper demonstrates that increasing the synthetic effective pixel count by exploiting super-resolution (SR) imaging results in improved performance. To this end, we investigated the performance of a CMOS camera-based THz dispersive spectroscope using SR imaging. From 0.75–0.9 THz, average spectral resolution improved from 76 GHz to 34.2 GHz (about a factor of two), while the average frequency accuracy enhanced from 30 GHz to 1.65 GHz. Further to providing enhanced spectral resolution and frequency accuracy, our results provide an insight into the fundamental performance limits. For low-resolution (LR) imaging, the finite pixel count sets the spectral resolution limit, and for SR imaging, the camera angular resolution defines the limiting factor. For this reason, SR imaging generally improves the spectral resolution at least by a factor of two. Pixel count and noise fluctuation limit the frequency accuracy using LR and SR imaging, respectively., This document is the accepted manuscript version that has been published in final form in IEEE Transactions on Terahertz Science and Technology at https://doi.org/10.1109/TTHZ.2021.3088278. © 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

Silicon lenses are widely employed to turn a terahertz (THz) focal-plane array into a THz camera. For the first time, we have identified the type of radial distortion caused by such lenses. To this end, we measured all single-pixel far-field radiation patterns of a 15-mm diameter 2.75-mm extended hemispherical silicon lens-integrated 32��32-pixel CMOS camera at 0.652 THz. From this, a beam incidence angle grid has been generated, indicating barrel distortion. The measured beam incidence angle is compared to a previously published closed-form relation between scan angle and feed position for extended hemispherical lenses. The presented results are essential for all beam switching applications based on dielectric extended hemispherical lenses with an elliptical extension realized in the lens center., This document is the accepted manuscript version that has been published in final form in: 2021 46th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) at https://doi.org/10.1109/IRMMW-THz50926.2021.9567497. �� 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

We employ a lens-coupled CMOS terahertz camera to measure the dispersion of an inexpensive reflective diffraction grating. Thus, although the terahertz camera was originally intended for terahertz imaging applications, we show that it can be re-purposed to perform spectral analysis. Two different experiments to determine the spectral content of a source under test are performed. These experiments target separate frequency bands, and hence they must make use of different sources and gratings. As such, we demonstrate a modular and low-cost technique for spectral analysis in the terahertz range., This document is the accepted manuscript version that has been published in final form in: 2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz). https://doi.org/10.1109/IRMMW-THz.2018.8510246 © 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

An array of terahertz sources in 0.13 μm SiGe BiCMOS has previously been developed to mitigate the well-known issue of low available power from compact terahertz sources. However, the device projects beams toward different, non-overlapping directions, rendering it unsuitable for use as a general-purpose illumination source. To address this issue, custom optics are employed for incoherent power combining, and subsequently utilized in a demonstration of terahertz imaging., This document is the accepted manuscript version that has been published in final form in: 2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz). https://doi.org/10.1109/IRMMW-THz.2018.8509901 © 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

In this letter, we demonstrate amorphous indium-gallium-zinc-oxide (IGZO) thin-film transistors (TFTs) with a maximum transit frequency (fT) of 1.1 GHz and maximum oscillation frequency (fmax) of 3.1 GHz, which set a new record for metal-oxide TFTs based on scalable and cost-effective process techniques. A key for the outstanding high-frequency performance of our TFTs is an optimized two-step self-alignment concept, which allows the rigorous minimization of parasitic elements, that typically limit high-frequency operation. We expect that our results will inspire a wide range of high-frequency circuits based on metal-oxide electronics., This document is the accepted manuscript version that has been published in final form in: 2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz). https://doi.org/10.1109/LED.2020.3029956 © 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

There is a need to reduce the cost and size of functional terahertz devices, in order to expedite this notoriously under-utilized frequency band toward practical applications. Electronic integrated circuits (ICs) are extremely useful to this end, as they provide a means to achieve miniaturization and mass-production, leveraging the foundries and techniques that have made digital electronics ubiquitous. Although integration of terahertz systems is expected to diminish performance and functionality, the increased number and availability of devices is likely to compensate for such disadvantages. In this work, we develop a terahertz-range spectroscope that combines a CMOS terahertz camera with custom-machined reflective optics. It is noted that the individual pixels of the camera employ incoherent detection, and hence a single pixel is not able to differentiate distinct frequencies. For this reason, the reflective optics are designed to split a terahertz beam into its constituent frequencies, and target each to a different position on the terahertz camera’s focal plane array. The required frequency-scanning functionality is provided by a corrugated reflective optic that operates in a manner similar to a curved diffraction grating. The developed spectroscope is experimentally validated, and its functionality agrees closely with simulation. This work provides a pathway to a new generation of compact, low-cost, all-electronic terahertz spectrometers that employ mass-producible silicon ICs for all active components., This document is the accepted manuscript version that has been published in final form in IEEE Transactions on Terahertz Science and Technology at https://doi.org/10.1109/TTHZ.2020.3004516. © 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

This paper discusses advances related to the integration of future mobile electronic THz systems. Without claiming to provide a comprehensive review of this surging research area, the authors gathered research on selected topics that are expected to be of relevance for the future exploration of components for practical mobile THz imaging and sensing applications. First, a brief technology review of integrated mobile THz components is given. Advances in III-V technology, silicon technology, and resonant-tunneling diodes (RTD) are discussed. Based on an RTD source and a SiGe-HBT direct detector, low-cost and compact computed tomography is presented for volumetric continuous-wave imaging at around 300 GHz. Moreover, aspects of system integration of mobile THz MIMO radars are discussed. Thereby, a novel phase-locked loop concept utilizing a high-stability yttrium-iron-garnet-tuned oscillator to synthesize ultra-stable reference mmWave signals is shown, and an adaptive self-interference cancellation algorithm for THz MIMO in the digital domain based on Kalman filter theory is proposed.

Terahertz waves cover photon energies that are orders of magnitude smaller (0.4-40 meV) than the visual spectrum. Therefore, they provide additional information on intrinsic condensed-matter properties, making them attractive for imaging applications in the life sciences [1], [2]. Furthermore, they do not have an ionizing effect and are considered biologically innocuous. The ever-present water in organic matter strongly absorbs terahertz waves, and subtle changes in the water concentration can be indicative of disease [3]. However, the waves? long wavelength (3mm-30 nm) severely limits their lateral resolution and creates challenges for high-resolution imaging of biological tissue on the cellular level, e.g., for tumor margin identification during cancer surgery.

We demonstrate a fully-integrated 0.56 THz 128-pixel near-field 1-D sensor array with 10–12 μm lateral resolution. The sensing elements are based two parallel cross-bridged split-ring resonators that utilize a 3-D topology to exhibit high field confinement in the sensing spot. The sensor comprises a scalable excitation scheme that is designed to maximize the fill factor of the imager for large 1-D arrays. The THz front-end is co-integrated with a digital-read out chain. This enables rapid THz near-field image acquisition of planar and soft surfaces. Furthermore, the imager can be operated as a standalone device that is only powered with a USB cable. As an exemplary application, this work demonstrates THz near-field sensing as a tool for biometric fingerprint reading for the first time.

Real-time terahertz video cameras are regarded as key enabler systems for numerous applications. Unfortunately, their spatial resolution is fundamentally restricted by the diffraction limit. Near-field-scanning optical microscopy (NSOM) is used in the THz domain to break through this limit [1]. Recently reported THz near-field sensors based on silicon technology promise significant improvements compared to NSOM with respect to sensor sensitivity, system cost, and scanning time [2,3]. However, only single-pixel implementations have been presented with unmodulated CW sources so far, which limits the sensors dynamic range (DR) due to detector 1/f noise. This paper scales-up the research of near-field sensing into larger surfaces made of a plurality of super-resolution pixels with video-rate imaging capabilities. The 128-pixel 0.56THz imaging array includes all functions such as illumination, sensing, detection, and digital readout on a single silicon chip.

International audience; Silicon tracking detectors operated at high luminosity collider experiments pose a challenge for current and future readout systems regarding bandwidth, radiation, space and power constraints. With the latest developments in wireless communications, wireless readout systems might be an attractive alternative to commonly used wired optical and copper based readout architectures.The WADAPT group (Wireless Allowing Data and Power Transmission) has been formed to study the feasibility of wireless data transmission for future tracking detectors. These proceedings cover current developments focused on communication in the 60 GHz band. This frequency band offers a high bandwidth, a small form factor and an already mature technology. Motivation for wireless data transmission for high energy physics application and the developments towards a demonstrator prototype are summarized. Feasibility studies concerning the construction and operation of a wireless transceiver system have been performed. Data transmission tests with a transceiver prototype operating at even higher frequencies in the 240 GHz band are described. Data transmission at rates up to 10 Gb/s have been obtained successfully using binary phase shift keying.

Today, electronics are implemented on rigid substrates. However, many objects in daily-life are not rigid — they are bendable, stretchable and even foldable. Examples are paper, tapes, our body, our skin and textiles. Until today there is a big gap between electronics and bendable daily-life items. Concerning this matter, the DFG Priority Program FFlexCom aims at paving the way for a novel research area: Wireless communication systems fully integrated on an ultra-thin, bendable and flexible piece of plastic or paper. The Program encompasses 13 projects led by 25 professors. By flexibility we refer to mechanical flexibility, which can come in flavors of bendability, foldability and, stretchability. In the last years the speed of flexible devices has massively been improved. However, to enable functional flexible systems and operation frequencies up to the sub-GHz range, the speed of flexible devices must still be increased by several orders of magnitude requiring novel system and circuit architectures, component concepts, technologies and materials.

DOTSEVEN is an ambitious research project aiming at pushing the limits of SiGe HBT technology, modeling, circuits, and systems towards mm- and sub-mm wave applications. The project with a 12.3 M€ total funding and a duration of 45 months started in late 2012 and has been sponsored by the European Commission. This paper gives an overview on the project goals, its organization, and selected results that have been achieved.

Future imaging applications in the submillimeter-Wave range (300GHz to 3THz) require RF systems that can achieve high sensitivity and portability at low power consumption levels. In particular, CMOS process technologies are attractive due to their low price tag for industrial, surveillance, scientific, and medical applications. Recently, CMOS-based detectors have shown good sensitivity up to 1THz with NEPs on the order of 66pW/√(Hz) at 1THz [1]. However, CMOS terahertz imagers developed thus far have only operated single detectors based on lock-in measurement techniques to acquire raster-scanned images with frame rates on the order of minutes [2]. To address these impediments, we present a low-power 1kpixel terahertz camera chip fully compliant with an industrial 65nm f t /f max =160GHz/200GHz CMOS process technology. The active-pixel circuit topology is designed to accommodate the optics for wide bandwidth (0.6 to 1THz) in stand-off detection with a 40dBi Si-lens. It includes row/col select and integrate-and-dump circuitry capable of capturing terahertz images with video frame rates up to 25fps at a power consumption of 2.5μW/pixel.

A 1 k-pixel camera chip for active terahertz video recording at room-temperature has been fully integrated in a 65-nm CMOS bulk process technology. The 32 × 32 pixel array consists of 1024 differential on-chip ring antennas coupled to NMOS direct detectors operated well-beyond their cutoff frequency based on the principle of distributed resistive self-mixing. It includes row and column select and integrate-and-dump circuitry capable of capturing terahertz videos up to 500 fps. The camera chip has been packaged together with a 41.7-dBi silicon lens (measured at 856 GHz) in a 5 × 5 × 3 cm3 camera module. It is designed for continuous-wave illumination (no lock-in technique required). In this video-mode the camera operates up to 500 fps. At 856 GHz it achieves a responsivity Rv of about 115 kV/W (incl. a 5-dB VGA gain) and a total noise equivalent power (NEPtotal) of about 12 nW integrated over its 500-kHz video bandwidth. At a 5-kHz chopping frequency (non-video mode) a single pixel can provide a maximum responsivity Rv of 140 kV/W (incl. a 5-dB VGA gain) and a minimum noise equivalent power ( NEP) of 100 pW/√Hz at 856 GHz. The wide-band antenna and pixel design achieves a 3-dB bandwidth of at least 790-960 GHz.

Summary form only given, as follows. This paper presents a lens-integrated terahertz imaging detector implemented in a 65 nm bulk CMOS process technology. The back-side illumination through a silicon lens increases the imaging SNR by 7–15 dB. The broadband detector design has been verified from 0.6 to 1 THz. At 1 THz the circuit achieves a noise equivalent power (NEP) of 66 pW/sqrt(Hz) and a responsivity (Rv) of 800 V/W for back-side illumination. The first 1 THz CMOS active imaging results with a lens are presented.

THz CMOS imagers integrated with hyperhemispherical Si-lenses are presented and characterized. FPAs are implemented in 65nm CMOS bulk and SOI technologies. Lens-integrated detectors at 0.65 THz show an increase of 15dB and 20dB in SNR compared to front-side illumination for SOI and bulk respectively. The responsivities R v are increased and a minimum noise-equivalent power NEP of 17pW/√Hz is measured for SOI detectors with the lens. THz Images are presented.