Renato Negra

• RWTH Aachen University

This article describes the design of a 28-GHz bidirectional 4-element beamformer chip based on a 4-way ultracompact switchable power divider (SPD). The addition of the divider solves the ineffective power splitting and the inefficient use of valuable chip area. Therefore, this work is devoted to remove the drawbacks associated with the Wilkinson po...

Research on thin-film technology-based radio frequency (RF) circuits is increasing to address the demand for transparent, wireless, and wearable consumer electronics applications. Owing to their excellent electronic and mechanical properties, two-dimensional materials (2DMs) are candidates with high potential for such applications. The 2DMs graphen...

Harvesting radio frequency (RF) energy is an attractive solution for powering ultralow-power (ULP) devices. However, harvesting efficiently from different RF power levels is still a challenge. This work presents a wide power range RF harvester composed of a rectifier circuit and a power management integrated circuit (PMIC). Such a wide range is ach...

This work describes accurate methods for the characterization of sub-terahertz (sub-THz) devices and pad de-embedding procedures. The extraction of the intrinsic DUT is enabled by generating a precise pad model using two-tier calibration approaches. Moreover, the proposed approaches offer a solution to the designers to preserve precious silicon are...

This work presents the design, implementation, and characterisation of a Ka -band thin-film two-stage compact analogue phase-shifter. The design exploits a reflective-type configuration which utilizes four metal-insulator-graphene diodes as reflective loads. The fabricated prototype is realised on a 8.1 µm-thick flexible polyimide (PI) substrate an...

This letter presents a power amplifier (PA) with excellent power-added efficiency (PAE) for millimeter-wave (mm-wave) applications. The high efficiency is achieved by leveraging a local backside etching (LBE) process to enhance the quality factor (Q) of the output matching network. The PA was fabricated in a mature SiGe BiCMOS technology featuring...

This work presents a 2D tellurium (Te)‐based diode that exploits the doping achieved by atomic layer deposited (ALD) Al2O3 to enhance its rectifying performance. The proposed device comprises a Schottky junction that is dielectric‐doped to significantly reduce the reverse bias current. A boosted current responsivity four times higher compared to th...

This work presents the full analysis and implementation of a proof-of-concept monolithic millimeter-wave integrated circuit (MMIC) that behaves as a subharmonic parametric downconverter mixer. Contrarily to other integrated parametric downconverters, the circuit exploits the optimized, high nonlinear C- V characteristics of a diode-connected SiGe h...

This work presents the analysis, design, and implementation of a fully integrated loss-compensated cascaded multistage distributed amplifier (LC-CMSDA) in 65nm CMOS technology. The proposed LC-CMSDA consists of three distributed stages in cascade configuration. The input stage utilizes three gain-cells in a distributive topology and offers 10 dB of...

Wide-bandgap semiconductor devices, such as gallium nitride (GaN) or silicon carbide (SiC), are key enablers for innovative power electronic circuit topologies. However, novel types of isolated gate drivers with high common-mode transient immunity (CMTI) and high switching speed need to be developed to put these benefits into action. We propose a r...

This letter presents a broadband amplifier with gain variation of less than $\pm$ 0.75 dB and small group delay variation over the frequency band from 165 to 220 GHz. Different from the commonly used multiband matching approach, in this work a common broadband amplification stage is focused for the flexibility and scalability. In the common stage...

The research of two-dimensional (2D) Tellurium (Te) or tellurene is thriving to address current challenges in emerging thin-film electronic and optoelectronic devices. However, the study of 2D-Te-based devices for high-frequency applications is still lacking in the literature. This work presents a comprehensive study of two types of radio frequency...

Ambient energy harvesting has great potential to contribute to sustainable development and address growing environmental challenges. Converting waste energy from energy-intensive processes and systems (e.g., combustion engines and furnaces) is crucial to reducing their environmental impact and achieving net-zero emissions. Compact energy harvesters...

This article reports on exploiting a nonlinear capacitance compensation technique to achieve high linearity for power amplifier (PA) designs in III–V semiconductor technologies. High linearity is achieved by implementing multiple transistors with deliberate sizes and biasing to compensate for each nonlinear input capacitance behavior. Therefore, th...

This first chapter of the book is dedicated to resonant circuits. The frequency response and other important properties of inductances, capacitances and resonant circuits are introduced. Examples for applications in impedance matching circuits and filters will be provided. Understanding resonator properties like frequency response, quality factor a...

This article presents the detailed design procedure of a millimeter-wave low-power fully integrated monolithic millimeter-wave integrated circuit (MMIC) parametric upconversion circuit in SiGe heterojunction bipolar transistor (HBT) BiCMOS technology. This article comprehensively describes the design considerations to fully exploit the abrupt $C$...

This work presents the analysis, design, and implementation of an efficient and wideband active-split dual-feed distributed amplifier (AS-DFDA) in 0.13μm CMOS technology. It consists of a dual-feed (DF) output stage with a passive combiner and an active-split (AS) input stage. The dual-feed stage is used to enhance the gain and output power of the...

This article presents the principle of extending the back-off efficiency of a three-stage Doherty power amplifier (DPA) by substituting the second load modulation stage using a load transformation stage. Thereby, the DPA output combiner is split into two independent circuits so that the second peaking PA, peaking II, can act as a reflector for the...

This letter presents a distinct approach to linearize Chireix outphasing power amplifiers (PAs), which is leveraging the multilevel linear-amplification-with-nonlinear-components (LINC) concept. The proposed architecture operates only on phase-modulated signals and is therefore compatible with digital-like signal generation and distribution. The an...

This article presents a broadband three-stage pseudoload modulated balanced amplifier (P-LMBA) with enhanced power back-off efficiency. Unlike the conventional LMBAs, one of the balanced PA pairs of the proposed P-LMBA is modified to serve as the carrier amplifier, while the other one and the control amplifier (CA) are working as the peaking amplif...

This paper describes the design of a broadband Doherty power amplifier implemented in a 130-nm SiGe BiCMOS technology for 5G applications (24.25-29.5 GHz band) with a compact size of 1.12 mm2. Unlike other works at similar frequencies, the broadband amplifier employs an ultra compact single-section broadband lumped-element Wilkinson power splitter...

Over the past two decades, the research on two-dimensional materials has received much interest. Graphene is the most promising candidate regarding high frequency applications thus far due to is high carrier mobility. This review discusses the research about the employment of graphene in micro- and millimetre-wave circuits. The review starts with t...

We demonstrate the design, fabrication, and characterization of wafer-scale, zero-bias power detectors based on two-dimensional MoS2 field effect transistors (FETs). The MoS2 FETs are fabricated using a wafer-scale process on 8 μm thick Polyimide film, which in principle serves as flexible substrate. The performances of two CVD-MoS2 sheets, grown w...

We demonstrate the design, fabrication, and characterization of wafer-scale, zero-bias power detectors based on two-dimensional MoS$_2$ field effect transistors (FETs). The MoS$_2$ FETs are fabricated using a wafer-scale process on 8 $\mu$m thick polyimide film, which in principle serves as flexible substrate. The performances of two CVD-MoS$_2$ sh...

This letter reports on the analysis and the design of a novel N-way single-inductor power divider (PD), which allows for a compact size regardless of the number of ports. Moreover, the reported topology simplifies the interconnection of the isolation resistors, making the design of PDs with more than four ports straightforward and systematic. Final...

The main design principles in computer architecture have recently shifted from a monolithic scaling-driven approach to the development of heterogeneous architectures that tightly co-integrate multiple specialized processor and memory chiplets. In such data-hungry multi-chip architectures, current Networksin- Package (NiPs) may not be enough to cate...

Worldwide, regions are on the verge of collapse due to an ongoing urbanization and an increasing number of cars. To relieve overcrowded roads, future urban mobility has to become more flexible and more efficient. The idea of transmodular mobility is to change and share different transportation carriers within a higher-level transportation system. T...

In this work, an adaptive piecewise linear diode model is presented for class C rectifier design. The model is developed based on conventional piecewise linear diode model and curve fitting to extract the model parameters for different input power and load situations. The accuracy of the model is evaluated by comparing the calculated power conversi...

In article 2001210, Max C. Lemme and co‐workers highlight recent advances in 2D/3D heterostructures with graphene. The article demonstrates the advantages of metal‐insulator‐graphene diodes and graphene‐silicon Schottky diodes for radio frequency circuit applications and photodetection, with outstanding figures‐of‐merit comparable to or even outper...

Graphene has unique electrical and mechanical properties which can pave the way for new types of devices for microwave applications. However, emerging technologies often have problems with yield and still considerable variation in device parameters cause great challenges for circuit design. In this paper, we present the design and development of an...

This paper presents a dual-polarization beamformer chip for 5G applications. The chip leverages on a vector-sum phase shifter approach and single-ended design, allowing a reduced control circuitry complexity. The use of the vector-sum phase shifter translates in both phase shift and gain control, as shown in the system analysis. This beamformer is...

GaN-based high electron mobility transistors (HEMT) on Si (111) substrates have large potential for applications in the 5G telecommunication field. However, for this potential to be fully realized, all loss mechanisms need to be minimized. It is known that typical metal-organic chemical vapor deposition (MOCVD) processes used to grow the GaN epitax...

This paper presents a comparative study between two different implementations of digitally-controlled-oscillators (DCOs), whcih is the DAC-based and the digital controller-based DCO in TSMC 65 nm CMOS technology. This paper focuses on ring-oscillator architectures due to their high stability against PVT. The DAC-based oscillator implements a differ...

Thickness-modulated lateral MoS2 diodes with an extracted benchmark cutoff frequency (fc) of up to 126 GHz are implemented and fully characterised. Fabricated diodes demonstrate an on-off current ratio of more than 600 and a short circuit current responsivity at zero-bias of 7 A/W. The excellent performance achieved in our device is attributed to r...

This article presents a fully integrated Fourier-domain digital-to-analog converter-based transmitter (Tx). The proposed topology generates a coherent bandwidth (BW) of up to 2 GHz by exploiting the relationship between the discrete and the continuous-time Fourier transform. Thus, the digital-to-analog converter (DAC) sampling rate and the entire d...

Diodes made of heterostructures of the 2D material graphene and conventional 3D materials are reviewed in this manuscript. Several applications in high frequency electronics and optoelectronics are highlighted. In particular, advantages of metal–insulator–graphene (MIG) diodes over conventional metal–insulator–metal diodes are discussed with respec...

Diodes made of heterostructures of the 2D material graphene and conventional 3D materials are reviewed in this manuscript. Several applications in high frequency electronics and optoelectronics are highlighted. In particular, advantages of metal-insulator-graphene (MIG) diodes over conventional metal-insulator-metal diodes are discussed with respec...

Die zunehmende Massenmotorisierung und ansteigender Wohlstand standen jahrelang in einem kausalen Zusammenhang, sodass erstere überwiegend positiv konnotiert wurde. Inzwischen geht die umfangreiche Nutzung privater Personenkraftwagen im städtischen Kontext jedoch mit mannigfaltigen Problemen einher. Die verkehrsinduzierten Belastungen umfassen bspw...

This work presents the design, implementation, and characterization of the first thin-film integrated tunable microwave harmonic generator. The design is realized by exploiting the nonlinearity of four chemical vapor deposition (CVD) graphene-based diodes arranged in a nonlinear transmission-line (NLTL) approach. The used thin-film monolithic micro...

This article presents a fully integrated radio frequency (RF) rectifier on a flexible polyimide (PI) substrate. This circuit is designed and implemented using a chemical-vapor-deposition (CVD) graphene monolithic microwave integrated circuit (MMIC) process, where a metal–insulator–graphene (MIG) diode is employed to obtain the necessary nonlinearit...

Abstract A high‐temperature 2.1 GHz oscillator based on a AlGaN/GaN high electron mobility transistor (HEMT) is successfully designed, implemented, and characterised for the first time. The system is explicitly designed such that the final circuit consists of a single transistor bonded to a printed circuit board (PCB), and no further passive compon...

This article reports on the theory and application of a high-speed Marx generator (HSMG) circuit to realize supply modulation (SM). In order to achieve high-modulation bandwidth, the supply modulator complexity is kept low, enabling multilevel SM with four discrete voltage levels. A prototype is designed and fabricated on a four-layer FR4 board. Th...

Worldwide, regions are on the verge of collapse due to the ongoing urbanization and an increasing number of cars. In order to relieve overcrowded streets, the airspace above the ground must be opened for urban mobility. Aircraft taxis are the logical option to develop urban airspace for private transport. However from a long-term perspective, these...

The main design principles in computer architecture have recently shifted from a monolithic scaling-driven approach to the development of heterogeneous architectures that tightly co-integrate multiple specialized processor and memory chiplets. In such data-hungry multi-chip architectures, current Networks-in-Package (NiPs) may not be enough to cate...

A rectifier with an inductive matching network can reach good efficiency within a very compact size, and hence, became popular recently. In this letter, a general design solution for the inductive matching network is provided. A criterion for using the inductive matching technique is derived to evaluate the suitability of a specific diode for this...

In this work, an evaluation of the performance of discrete elements intended for an ${L}$ -band high-temperature GaN-based LC -oscillator is carried out between room temperature and 300 °C. GaN high-electron mobility transistors (HEMTs) on sapphire substrate, metal–insulator–metal (MIM) capacitors, thin-film inductors, and resistors on sapphire...