Europe is a pioneer in the use of SiGe technologies for the production of mm-wave systems. In this context, the TARANTO project (H2020 ECSEL JU) made it possible to bring together some major players in the field, whether at the industrial or academic level. The proposed workshop will show some results from the TARANTO project, allowing, in addition to showing the feasible systems, to understand how the realization of complex systems was approached.

The objective of the circuits and systems presented through the five presentations comprising the workshop is linked to the miniaturization of wireless systems, the increase in radar resolution and the realization of high speed transmission systems. These objectives can be achieved when working at frequencies located in the mm-wave band, typically between 30 GHz and 300 GHz. Several types of circuits, systems and applications will be discussed, FMCW radars, on-wafer calibration of passive phase shifters for antenna arrays, high speed ADC / DAC, time interleaving schemes and E-band transceiver.

120-GHz and 240-GHz FMCW Radar Demonstrators in B11HFC Technology for Industrial and Consumer Applications

Christoph Mangiavillano / Andreas Haderer

The advancements in SiGe BiCMOS technology has enabled the mass commercialization of automotive radars working at 24-GHz and 77-GHz bands. Besides the automotive market, industrial monitoring systems and many consumer products (such as drones, smartphone and watches) are aiming to utilize the unique advantages of mm-wave radar systems. Miniaturization of radar sensors is a key requirement for achieving market success in these applications. By moving to higher frequency bands, which is supported by constant increase in fT and fmax, being one of primary goals of the TARANTO project, there is a vast potential of miniaturization both in the size of the chips and the associated antennas. In this talk, we will present two FMCW radar demonstrators working at more than 100 GHz, a) A wideband, high power multichannel 4-RX, 2-TX radar with high speed TX modulators and IQ receivers, and b) a fully differential 240-GHz high power radar. We will provide the details and present the characterization results of each of the two radar sensors. We will also discuss the advantages of the architectures chosen for the radars in the context of chip performance and the application scenarios. The 120-GHz radar demonstrator uses two MMIC chips with horn antennas, whereas the 240-GHz radar sensor includes the antennas-on-chip to achieve a very compact form factor.

Design and Test of mm-Wave Phase Shifters

Marc Margalef-Rovira / Manuel Barragan
University Grenoble Alpes

Current needs of high-data-rate and high radar resolution for automotive and mobile telecommunications has brought the transceiver frequency to the mm-wave band. In addition to the frequency increase, as compared to traditional telecommunication bands, the increase in data rate and in radar resolution can also be addressed by increasing the directivity of antennas. In this context, given that automotive and mobile applications involve moving transceivers, beam steering techniques are required.

In this talk, we will address the design and test of the main block for on-chip beam steering systems, the phase shifter. The presentation will focus on three main aspects of the design of a Reflection-Type Phase Shifter: (i) the design of the 3-dB coupler and (ii) the highly reflective load, and (iii) the Oscillation-Based-Test for phase shifters calibration during their operation. Measurements of several devices and circuits with working frequencies ranging between 60 GHz and 325 GHz will be presented.

79 GHz Sequential Sampling Pulse Radar

Alexander Leibetseder

In this presentation, a compiled summary of our work on the “79 GHz Sequential Sampling Pulse Radar” is shown. After a short introduction about the SSPR concept and signal model, some key features of the concept are illuminated. The introduction is followed by a section about a selection of the designed circuits and built demonstrators. The presentation of recent measurement results, which underline the advantages of the SSPR, conclude the talk.

Advanced SiGe Key ICs for Broadband Communication Systems

Philipp Thomas
University of Stuttgart

Network traffic will see significant increase as mobility gets more intelligent and connected, demanding high data rates from vehicles themselves as well as from the surrounding infrastructure. For higher data rates, microwave receivers and transmitters need increased bandwidth to employ modern communication standards like 5G.

While CMOS is the choice for cost-effective analog-to-digital converters (ADC) in broadband receivers, it cannot provide the necessary bandwidth alone at this moment. That is where analog SiGe front-ends show their full potential. Ultra-high bandwidth input signals can be deployed to a number of parallelized ADCs that only need a fraction of the initial bandwidth to provide the digital output stream. Ultra-broadband digital-to-analog converters (DAC) are another key component for the core data network. Especially as the analog bandwidth of the electrical components is a bottleneck in transmitters, advanced concepts for higher bandwidth have to be implemented. A shift to hybrid DAC systems is a viable option, where the DSP is implemented in CMOS, whereas the analog front-end is implemented in SiGe-BiCMOS technology, which enables ultra-high bandwidth with advanced transistors. The extremely high cutoff frequencies of SiGe heterojunction bipolar transistors (HBT) enable the design of front-end circuits up to the domain above 100 GBaud. The European Union has identified this technology as a key enabler to broadband communication systems and is funding the project TARANTO within the ECSEL initiative, thrusting technology, circuit design and system implementation in the area.

Advancements in the mentioned SiGe key ICs realized within this project will be the main focus of this talk. Besides developed ADC front-ends by URM1 and USTUTT, this talk will also outline the corresponding challenges and experiments with a demonstrator test setup of NOKIA. Both synchronous (STI) and asynchronous (ATI) time-interleaving schemes will be introduced to show their potential to contribute to an efficient infrastructure for future applications with severe data traffic. The proof of concept will be delivered by the results of electrical and optical experiments using a charge-sampling analog demultiplexer in one of the most advanced SiGe BiCMOS technologies at the moment. The implementation of transmitter DACs in SiGe technology instead of CMOS is an approach for enhanced transmitter bandwidth employed by MICRAM. Another option is synchronous time interleaving using an analog multiplexer (AMUX) as developed by USAAR. Advancements in both approaches are accomplished within the TARANTO project and will be presented.

Building blocks for an “Advanced multi-Gigabit” front-end for mmWave backhauling application

Alessandro Fonte
SIAE Microelettronica

In this talk the system specifications and the building block design of an “E-band radio transceiver front-end for mm-wave back-hauling applications” will be shown. This module will be the core of an “Advanced multi-GigaBit E-band radio” designed for a new generation of mm-wave point-to-point (P2P) radio links. All the building blocks have been designed in SiGe BiCMOS 55nm process by STmicroelectronics. In fact, the possibility to use high-speed HBTs for mm-wave sections and MOSFET devices for bias control functions, played a key role allowing a remarkable cost reduction and improving the integration capability, especially in mm-wave radio. In that context, the E-band backhaul is particularly attractive for several reasons: i) the high capacity that can be reached; ii) the possibility to have very large channel bandwidths; iii) the links that are often licensed under a “light license” process so that the licenses can be obtained quickly and cheaply by providing, at a fraction of the cost, the full benefits of traditional link licenses. Moreover this development will have a strong industrial impact since E-band P2P market is expected to increase more than 20% in the next ten years.

The work shown in this talk has been carried out within the ECSEL project “TARANTO”, by SIAE Microelettronica, ST Microelectronics, Università degli studi di Roma La Sapienza, Università degli studi di Modena e Reggio Emilia, Politecnico di Milano, Università di Calabria and Università degli studi di Pavia.