In the DFG research project TIEMPO, an I/Q transceiver for spread-spectrum radar operating in the frequency range from 220 GHz to 420 GHz is researched. This would correspond to a record bandwidth of 200 GHz. Based on the idea of the frequency modulated continuous wave (FMCW) comb radar, a new concept is studied that can be viewed as a digital radar counterpart to a frequency comb radar. To achieve the very wide bandwidth, a novel system architecture implementing a “chess-board spectrum division” will be investigated. Thanks to an elegant system level solution, a single oscillator at a fixed frequency is sufficient to generate five local oscillator (LO) carrier frequencies to cover the entire bandwidth. Furthermore, due to the high-speed I/Q mixed-signal components in combination with the “chess-board” concept, we reduce the number of required transmit/receive channels by two. The wide bandwidth imposes difficult challenges at the circuit design level:

1. I/Q data converters with 7-bit resolution, 20 GHz bandwidth, and 40 Gbps data-rate

2. I/Q transmitter and receiver operating above 400 GHz

3. LO signal generation to cover the entire bandwidth

4. On-chip antennas with 200 GHz bandwidth and high efficiency

To prove the concept, advanced semiconductor technologies, such as 22 nm FD-SOI (Fully-Depleted Silicon-On-Insulator) CMOS of Globalfoundries is considered. The operation frequencies are close or above f_max of available semiconductor technologies. This requires novel circuit and system level analyses and approaches to circumvent technology limitations. To our knowledge, this is the first digital spread-spectrum radar transceiver concept proposed in this frequency range, and the first operating over a bandwidth of 200 GHz.

TIEMPO Team:

Prof. Vadim Issakov, V.Issakov@tu-braunschweig.de
Yannick Wenger, y.wenger@tu-braunschweig.de
Finn Stapelfeldt, PhD Student, (funded by DFG), f.stapelfeldt@tu-bs.de

Prof. Frank Ellinger, frank.ellinger@tu-dresden.de
Dr. Corrado Carta, corrado.carta@tu-dresden.de
Dr. Christian Matthus, Postdoc, (funded by DFG), christian.matthus@tu-dresden.de

Prof. Robert Weigel, robert.weigel@fau.de
Marco Dietz, marco.dietz@fau.de
Kai Scheller, PhD Student, (funded by DFG)

Emerging around the year 2000, THz bioanalytic techniques have become a strongly growing field of research, since many biomolecules and biomolecular complexes show a rich and relevant intra- as well as intermolecular resonance spectrum in the THz regime [1-3].

The MATISSE project aims beyond individual biomolecular detection, towards the THz analysis and detection of more complex entities and complexes at the root of intercellular signaling and disease propagation: vesicular structures. Vesicles are found inside the cell transporting contents to the outside but also extracellularly as so-called exosomes. These exosomes are cell-to-cell transit systems in the human body with pleiotropic functions in the focus of recent research interest (cf. [4]). Exosomes are excellent non-hazardous model systems for potentially dangerous viruses, that also belong to the group of vesicles, like e.g. SARS-CoV2.

All these small biological structures (viruses, exosomes) carry and present marker molecules on their surface, by which specific detection is possible. However, detection is still time consuming, requiring advanced biomedical techniques and appropriately trained professionals. To exemplify this using the current problem of SARS-CoV2: Highly specific and sensitive detection is currently only possible by an indirect, time consuming technique, the detection of viral RNA after reverse transcription and amplification by PCR. Faster tests focus of the detection of a viral protein; however, these are known to be less sensitive and specific.

In the MATISSE project, a microfluidic THz biochip with integrated active electronic read-out will be developed for the fast and reliable detection of exosomes and virus particles with high specificity. Our distant aim is that body fluids, potentially carrying virus particles, will pass through the microfluidic THz biosensor and said virus particles are kept by an antibody against structures on their surface (e.g., the Spike protein in the case of SARS-CoV2). After accumulation of potentially present particles, these are detected via THz technology. Sufficient positive and negative controls will make a selective distinction and quantification possible, apart from simple yes/no answers.

Ref:
[1]    A. Markelz, et al., “Pulsed terahertz spectroscopy of DNA, bovine serum albumin and collagen between 0.1 and 2.0 THz,” Chem. Phys. Lett. 320, pp. 42–48, 2000.
[2]    M. Walther, et al., “Far-infrared vibrational spectra of all-trans, 9-cis and 13-cis retinal measured by THz time-domain spectroscopy,” Chem. Phys. Lett. 332, pp. 389–395, 2000.
[3]    R. J. Falconer et al., “Terahertz Spectroscopic Analysis of Peptides and Proteins,” J Infrared Milli Terahz Waves 33, pp. 973–988, 2012.
[4]    R. Kalluri et al., “The biology, function, and biomedical applications of exosomes,” Science 367, 2020.

MATISSE Team:

Prof. Anja katrin Bosserhoff, anja.bosserhoff@fau.de,
 

Prof. Bhaskar Choubey, Bhaskar.Choubey@uni-siegen.de
 

Prof. Peter Haring Bolívar, peter.haring@uni-siegen.de
Dr. Anna Katharina Wigger, anna.wigger@uni-siegen.de
Merle Richter, PhD Student, merle.richter@uni-siegen.de
Yannik Loth, PhD Student, yannik.loth@uni-siegen.de

The ultimate goal of the ITISA project is to develop the first integrated terahertz (THz) time-domain spectroscopy (TDS) system for space applications. Our project will employ and further advance the following three very recent photonic developments. First, driven by their key role in frequency comb technologies, appropriate femtosecond lasers are becoming space-ready, and have already been employed on satellites and sounding rockets. Second, one of the project partners has recently pioneered broadband, spintronic THz emitters. These sources cover the entire range from 0.3 to 30 THz, which is a highly interesting frequency range for space missions. The polarization plane of the emitted THz waves can be manipulated at THz frequencies. Third, the fundamental building blocks of a THz-TDS system are meanwhile in principle all chip-integrable.

In the first period of the priority program, we have, as proven by 13 publications and 1 patent arising from the project, very successfully developed and tested all building blocks for a THz system with a bandwidth ranging from 0.3 to 30 THz. Thereby we have laid the foundations to develop a demonstrator for a specific use case , rover-based analytics of regolith on the moon, up to a TRL of 6. The device will be operable without any moving parts. All building blocks and their underlying concepts are fullfilling the following features: 

• Photon-efficiency and compatibility with those femtosecond lasers that are currently developed for operation in space
• matching of the requirements of space applications such as compactness, minimal weight, minimal power consumption, radiation hardness, robustness against temperature and vibrations
• integrability of all key components on a chip

We emphasize that the potential applications of our developments will significantly go beyond space applications. First, they will generally meet the requirements to operate on compact mobile devices (e.g. rovers or drones) under harsh conditions. Second, our advancement of most recent THz generation and detection concepts is beneficial for the whole field of THz TDS.

ITISA Team:

Prof. Michael Gensch, (Deutsches Zentrum für Luft und Raumfahrt – Berlin), michael.gensch@tu-berlin.de
Dr. Nikola Stojanovic, (Institut für Optische Sensorsysteme - Berlin), nikola.stojanovic@dlr.de
Prof. Dirk Plettemeier, (Technische Universität Dresden), dirk.plettemeier@tu-dresden.de
Sujay Charania, (Technische Universität Dresden), sujay.charania@tu-dresden.de
Prof. Tobias Kampfrath, (Freie Universität Berlin), tobias.kampfrath@fu-berlin.de
Dr. Tom Seifert, (Freie Universität Berlin), tom.seifert@fu-berlin.de