A SiGe HEMT Mixer IC with Low Conversion Loss

The authors present the first SiGe HEMT mixer integrated circuit. The active mixer stage, operating up to 10GHz RF, has been designed and realized using a 0.1µ µµ µm gate length transistor technology. The design is based on a new large-signal simulation model developed for the SiGe HEMT. Good agreement between simulation and measurement is reached. The mixer exhibits 4.0dB and 4.7dB conversion loss when down-converting 3.0GHz and 6.0GHz signals, respectively, to an intermediate frequency of 500MHz using high-side injection of 5dBm local oscillator power. Conversion loss is less than 8dB for RF frequencies up to 10GHz with a mixer linearity of –8.8dBm input related 1dB compression point

A 200 GHz Monolithic Integrated Power Amplifier in Metamorphic HEMT Technology

A millimeter-wave monolithic integrated circuit power amplifier operating in the frequency range between 186 and 212 GHz is presented. The amplifier, dedicated to high-resolution imaging radar and communication systems, is realized in a 100 nm gate length metamorphic high electron mobility transistor technology. The three-stage design with four parallel transistors in the output stage achieves a linear gain of more than 12 dB and provides a saturated output power of more than 9 dBm and 7 dBm at 192 and 200 GHz, respectively

Development and RF-Performance of AlGaN/GaN and InAlN/GaN HEMTs on Large-Diameter High-Resistivity Silicon Substrates

A CMOS-compatible industrial processing and RF analysis of 150 mm GaN-on-HR-Si substrates with AlGaN and InAlN barrier is presented. Process development along with transfer to large-wafer scale is shown and some HEMT calibration devices produced on AlGaN/GaN following the aforementioned procedure are characterized in terms of RF-performance by using a set of measured multi-bias S-parameters. An automatic small-signal equivalent circuit extraction strategy for these AlGaN/GaN DUTs is validated and some de-embedded figures of merit are drawn out in order to initially evaluate this promising technology.This work is supported by the I Plan Propio de la Univ. de Málaga (PhD Grant-401), and the European Microwave Association™ by the EuMA Internship Award 2021 edition. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

The 2023 terahertz science and technology roadmap

Terahertz (THz) radiation encompasses a wide spectral range within the electromagnetic spectrum that extends from microwaves to the far infrared (100 GHz–∼30 THz). Within its frequency boundaries exist a broad variety of scientific disciplines that have presented, and continue to present, technical challenges to researchers. During the past 50 years, for instance, the demands of the scientific community have substantially evolved and with a need for advanced instrumentation to support radio astronomy, Earth observation, weather forecasting, security imaging, telecommunications, non-destructive device testing and much more. Furthermore, applications have required an emergence of technology from the laboratory environment to production-scale supply and in-the-field deployments ranging from harsh ground-based locations to deep space. In addressing these requirements, the research and development community has advanced related technology and bridged the transition between electronics and photonics that high frequency operation demands. The multidisciplinary nature of THz work was our stimulus for creating the 2017 THz Science and Technology Roadmap (Dhillon et al 2017 J. Phys. D: Appl. Phys. 50 043001). As one might envisage, though, there remains much to explore both scientifically and technically and the field has continued to develop and expand rapidly. It is timely, therefore, to revise our previous roadmap and in this 2023 version we both provide an update on key developments in established technical areas that have important scientific and public benefit, and highlight new and emerging areas that show particular promise. The developments that we describe thus span from fundamental scientific research, such as THz astronomy and the emergent area of THz quantum optics, to highly applied and commercially and societally impactful subjects that include 6G THz communications, medical imaging, and climate monitoring and prediction. Our Roadmap vision draws upon the expertise and perspective of multiple international specialists that together provide an overview of past developments and the likely challenges facing the field of THz science and technology in future decades. The document is written in a form that is accessible to policy makers who wish to gain an overview of the current state of the THz art, and for the non-specialist and curious who wish to understand available technology and challenges. A such, our experts deliver a 'snapshot' introduction to the current status of the field and provide suggestions for exciting future technical development directions. Ultimately, we intend the Roadmap to portray the advantages and benefits of the THz domain and to stimulate further exploration of the field in support of scientific research and commercial realisation

A Universal Large-Signal Model for Hetero Field Effect Transistors

The authors present an analytic, empirical largesignal model for the efficient simulation of Hetero Field Effect Transistors. The model has been extracted and verified for a 0.15µm AlGaAs/InGaAs/GaAs pHEMT as well as for a 0.2µm InP/InGaAs/InP pHEMT technology. It uses a new set of chargeconservative capacitance expressions as well as a dispersion model for accurate description of both static and dynamic IV characteristics. A large voltage regime is covered, ranging from the sub-threshold to forward gate conduction and linear to saturation operating regions. Typical HFET effects like self-heating, gain compression, impact ionization as well as particularities of capacitance characteristics are included. Model verification is carried out for static IV, high-frequency S-parameters as well as one- and two-tone power measurements at microwave frequencies for both types of transistors

Ultra wideband cascade low noise amplifier implemented in 100-nm GaAs metamorphic-HEMTS technology

We present a state-of-the-art broadband (60 to 90 GHz, 40%) 4-stage low noise amplifier (LNA) in a GaAs metamorphic high electron mobility transistor (mHEMT) technology. The LNA, spanning several waveguide bands, is dedicated to radiometry, communication and instrumentation applications. It consumes 56 mW and exhibits a gain of more than 19 dB with flat frequency response and average noise figure of 2.5 dB. The design makes use of reactive feedback by source degeneration. Broadband matching was achieved by using enhanced L-C matching networks. Gate width was optimized for best noise figure and gain performance

Impact of modulation type and baud rate on a 300 GHz fixed wireless link

This paper presents the transmission of broad-band complex modulated signals with data rates up to 64 Gbit/s using an analog front-end based on monolithic microwave integrated circuits (MMICs) at a carrier frequency of 300 GHz. Besides the typical modulation formats like BPSK, QPSK, and 16QAM a non-common modulation format 8APSK is introduced and measured. The maximal transmitted symbol rate is 32 Gbd. The signal quality is evaluated in terms of error vector magnitude, which shows values of -10.8 dB for BPSK and -10.10 dB for QPSK at a symbol rate of 32 Gbd and values of -14.8 dB for 16QAM at a symbol rate of 2 Gbd

Verification of a frequency dispersion modelin the performance of a GaAs pHEMT travelling-wave MMIC

The impact of frequency dispersive effects on typical figures of merit is investigated in a distributed MMIC realized in 0.15µm GaAs pHEMT technology. A novel compact dispersion model, allowing for accurate simulation of both static and dynamic multiple time constant IV characteristics, is employed. In a comparison of measurement and simulation, the model is both validated and used to quantify and interpret the error introduced when neglecting frequency dispersion in the design of MMICs. Device operation is investigated with respect to gain, linearity and power-added efficiency,all of them affected by dispersion effects. The model is shown to significantly improve simulation accuracy by increasing the validity range in terms of the frequency-and voltage regimes

E-band transmitter with 29 dBm RF power for satellite communication

In this paper an E-band transmitter chain with a maximum RF output power of 29 dBm for a 1 GBd QPSK signal is presented. The high output power is achieved by applying AlGaN/GaN-based power amplifiers as final stage of a module chain which further comprises a GaAs mHEMT-based quadrature up-converter, LO frequency multiplier-by-eight and driver amplifiers. The output power remains higher than 27 dBm for up to 6 GBd symbol rate and a modulation complexity of up to 32 QAM. In this work the effect of different PSK and QAM modulation format as well as the baud rate on the transmitted RF power level is studied through measurements. The linearity of the dual GaN PA module is evaluated for different types of modulation formats