IMS 2023
Modulation Characterization Enabling Design of High-Efficiency and Linear Power Amplifier Systems
Organizers:
Marc Vanden Bossche, National Instruments
Zoya Popović, University of Colorado
Abstract:
RF Power Amplifiers (PAs) play a dominant role in the system performance of wireless transmitters. PA designers are faced with the intractable goal of providing simultaneous high linearity and efficiency, as communications standards adopt ever higher modulation orders and bandwidths. Traditional PA design begins with a non-linear transistor model based on CW measurements. When the PA is measured under the desired modulated signals, degraded performance compared to simulation is commonly observed. Commercial adoption of phased arrays increases the disparity between traditional simulation and realistic measurements; coupling between antenna elements affects the PA performance in ways not accounted for in simulation. This workshop presents the next steps in improving design using modulation characterization to optimize global realistic performance of a system of PAs. The goal is to provide theoretical and practical background that can be applied directly at the lab bench. The workshop includes a practical demonstration using a commercial GaN device.
Advances in Microwave and mm-Wave Wideband Measurements for Radar and Communications Applications
Organizers:
Gian Piero Gibiino, Università di Bologna
Nicholas Miller, AFRL
Abstract:
Wideband measurement and characterization techniques at microwave and mm-wave frequencies are becoming increasingly demanding to satisfy the specifications of the ever-evolving communications and radar industry. This workshop presents recent research and technology advancements from industry, research centers, and academia, by discussing relevant performance metrics and their experimental evaluation across different hardware platforms. Advanced characterization techniques are presented for transistors, power amplifiers, and beamformers, encompassing over-the-air testing, linearity, load-pull, and calibration of precision radar. The first half of the workshop is dedicated to state-of-the-art wideband device characterization techniques and load-pull. The second half of the workshop is focused on beamformers and over-the-air characterization techniques and standards. Both the morning and afternoon sessions of this workshop will end with open interactive discussions useful to outline future trends and research on these topics.
IMS 2022
Emerging Low- Temperature/Cryogenic Microwave Techniques and Technologies for Quantum Information Processing
Organizers:
Alirio Boaventura, NIST
Michael Hamilton, Auburn University
Abstract:
Quantum computers hold the promise to perform certain complex calculations that are not solvable even with today’s most powerful supercomputers. Despite the significant progress made in the last decade in the science and engineering of quantum computation systems, several challenges remain before quantum computation can become practically usable. A key challenge relates to system scalability — fault-tolerant quantum computation will likely require thousands or millions of quantum bits (qubits), far beyond the capacity of current prototypes. Today’s most prominent candidate for implementing large-scale systems, the superconducting qubit platform, operates in the microwave regime and is controlled and readout via conventional microwave electronics operating at room temperature. While the current room temperature control and readout approach works for small-scale experiments, it is not scalable to thousands or millions of qubits. The engineering challenges of realizing practical large-scale systems present quantum microwave engineers with new opportunities in microwave modeling, design, and characterization of cryogenic semiconductor and superconductor devices, circuits, and systems. This workshop will address emerging techniques and technologies for quantum information processing, including low-temperature measurements and calibrations, cryogenic packaging and interconnects, monolithic semiconductor-based quantum processors, and quantum-classical interfaces based on cryogenic CMOS and Josephson superconductive electronics.
Measurement and Modeling of Trapping and Thermal Effects of GaN HEMT Microwave PA Technology
Organizers:
Nicholas Miller, AFRL
Sourabh Khandelwal, Macquarie University
Abstract:
Gallium nitride (GaN) high electron mobility transistors (HEMTs) are an excellent technology for various microwave power amplifier applications due to the underlying semiconductor’s wide bandgap, high breakdown voltage and large peak electron velocity. A key bottleneck to the technology’s widespread and long-term adoption into commercial and military applications is its inherent electrical reliability. The physical mechanisms of GaN HEMT electrical degradation are largely unresolved and actively under investigation. In this full-day workshop, international experts in the fields of microwave measurements, trap characterization, thermal characterization, reliability characterization, GaN HEMT nonlinear modeling, trap modeling, and TCAD modeling will present state-of-the-art research. This interactive workshop aims to inform and excite the attendees on the advances in multiple aspects of this technology. Starting with a GaN technology overview, the planned talks will inform the audience about measurement and characterization of this technology including the complex thermal, charge trapping, and long-term degradation phenomenon in these devices. The next part of the workshop covers the modeling and simulation research in GaN. Starting with an overview of modeling challenges in GaN devices, the workshop will cover the latest industry standard compact models and advances in TCAD-based modeling of GaN devices.
On-Wafer mm-Wave Measurements
Organizers:
Jian Ding, Spirit Semiconductor
Mike Geen, Filtronic
Nick Ridler, NPL
Xiaobang Shang, NPL
Abstract:
Accurate on-wafer S-parameter measurement plays an important role in the development of mm-wave integrated circuits for communications and electronics applications. To this end, a group of international experts in this field will share their experience on making reliable on-wafer measurements at high frequencies (eg above 100GHz). The presenters come from different backgrounds — instrumentation manufacturers, metrology institutes, end-users in industry and academia — and so provide different perspectives on this topic. The emphasis of the workshop is on sharing practical tips (ie good practice) so that attendees can subsequently implement such methods in their own workplaces. The workshop will cover topics including calibration techniques, verification methods, guides on design of custom calibration standards, instrumentation, and applications, etc. The workshop includes two panel discussions: (i) an open discussion about the challenges/opportunities/outlooks for research into on-wafer measurements in coming years; and (ii) an opportunity for attendees to describe their own on-wafer measurement problems so that these can be discussed, and hopefully solved, during the workshop.
IMS 2020/2021
Platforms, Trials, and Applications — The Next Step for 5G and Future Wireless Networks
Organizers:
Alberto Valdes-Garcia, IBM T.J. Watson Research Center
Christian Fager, Chalmers Univ. of Technology
Zhizhang Chen, Dalhousie University
Abstract:
Emerging RF technologies for 5G, such as MIMO, scaled phased arrays, and mm-wave transceivers, have reached a significant level of maturity enabling initial product deployments and standards completion. While RF-specific challenges remain, significant wireless R&D efforts around the world are now integrating the new RF capabilities into end-to-end wireless networking platforms and application demonstrations. Such testbeds and application proofs-of-concept (PoC) are key to accelerate the commercial deployment of 5G, augment its impact and value, and ultimately ignite the vision for what 6G may become. This workshop will present a comprehensive overview of multi-disciplinary efforts in the areas of advanced end-to-end platforms for wireless research, emerging 5G trials, and testbeds for new radio concepts. Common themes in the workshop are (1) the enablement and execution of real-world wireless experimentation and (2) projects where emerging RF hardware capabilities (such those provided by multi-antenna mm-wave systems) are a main differentiator. The expert speakers will present diverse perspectives on these topics including: university-led research, industry-lead research, government-academia collaborations, and deployments led by telecommunication equipment providers. The audience will gain a broad understanding of the challenges associated with incorporating RF hardware into these testbeds and performance results from platform-scale experimentation. Last, but not least, a common thread of discussion throughout the workshop, and particularly at the concluding panel, will be an initial set of requirements, concepts, and implementation challenges for 6G networks.
Calibrated Testbeds for the Characterization, Optimization and Linearization of Multi-Input Power Amplifiers
Organizers:
Apolinar Reynoso-Hernández, CICESE
Karun Rawat, IIT Roorkee
Abstract:
With the deployment of sub-6GHz 5G, a strong interest for power-efficient broadband amplifiers has emerged. Multiple-input PAs such as (1) outphasing power amplifiers (OPA) operating in the Doherty-Chireix continuum, and (2) load-modulated balanced amplifiers (LMBA) appear to provide promising opportunities. This workshop will focus on the new types of calibrated testbeds, test equipment and associated control and measurement techniques which have been developed for their characterization, optimization and linearization. The characterization of multi-input power amplifiers introduces new challenges. The different RF sources need to be phase locked if they do not share the same local oscillator (LO). The modulation needs to be time synchronized. The testbed itself needs to be calibrated at its test ports for (1) power, (2) LO phase and (3) group delay. The measurements also need to consider reflections since multi-input PAs are exhibiting dynamically varying input impedances. New types of test solutions are emerging to facilitate the characterization and linearization of multi-input PAs including: the use of multiport VNAs operated as multi-channel VSAs, the synchronization of modular instruments or the use of BIST (built-in self-test) combined with machine learning. In support of the workshop theme, two talks will also feature a review of the theory of multiple-input PAs such as OPA and LMBA to establish the drive requirements, and one talk will address the linearization of multi-input PAs. Emphasis throughout the workshop will be placed on describing the various testbeds developed, their calibration, and their use for the characterization, optimization and linearization of multi-input power amplifiers.
IMS 2019
Measurement and Design Techniques for Next-Generation Communication Systems
Organizers:
Antonio Raffo, University of Ferrara;
Patrick Roblin, Ohio State University
Abstract:
The design of future communication systems poses several challenges in terms of required bandwidth, power, efficiency, and costs. The workshop aims at discussing how these challenges can be tackled by adopting skills and techniques that, although acquired by the microwave community, are still too fragmented. More specifically, the workshop will focus on measurements, which are a crucial step at each design level, from semiconductor devices to circuits and systems. Speakers will show how a deep understanding of the measurement quality is of critical importance and remains an unavoidable step for the design of the next-generation microwave circuits and systems. Emphasis will be placed on wideband measurements accounting for new modulation techniques. Finally, different examples of circuit and system designs oriented to 5G and IoT applications will be presented. It will be emphasized how simulations and measurements merge together in modern design techniques to give rise to first-pass design strategies.
Measurement Challenges in Over-The-Air Testing
Organizers:
Jon Martens, Anritsu
N.B. Carvalho, Universidade de Aveiro
Abstract:
As radio integration proceeds apace for 5G, satellite and other applications, over-the-air testing requirements are increasing dramatically. This workshop covers topics related to both measurement fundamentals (spatial data fusion, calibration and synchronization concerns, traceability, etc.), to the structure and measurement requirements of the subsystems being analyzed and to more advanced topics (e.g., MIMO test beds, higher order measurements such as EVM). Even simple transmission phase measurements versus position/angle can be a challenge with disjoint frequency converters and path characteristics changing over the modulation bandwidth. Nonlinear characterization (including emulated load pull) is increasingly needed for the embedded power amplifiers in these systems. Some subsystems under test may employ multibeam scanning or element- level predistortion that require additional characterization considerations. Attendees at this workshop will hear some of the latest thinking in OTA measurements and procedures and how some recent changes in integrated radio/system designs will further influence the measurement landscape.
IMS 2018
Advanced Applications of Nonlinear Vector Network Measurements for broadband RF Power Amplifiers Design and Linearization
Organizers:
Karun Rawat, Indian Institute of Technology Roorkee, India;
Patrick Roblin, Ohio State University, USA
Abstract:
With the advent of 5G communication era, there is huge upcoming requirement of high data rate for supporting heterogeneous network. The key requirement such as spectrum efficient modulation schemes, multiple access techniques and carrier aggregation etc. are under investigation to handle spectral as well as energy efficient radio transmission. In particular, the radio frequency (RF) and microwave power amplifiers (PAs) and transmitters should meet these challenges of high bandwidth and efficiency. This essentially requires innovations in the area of nonlinear design and characterization to develop new generation of PAs and transmitters. This workshop will focus on the new areas explored in non-linear vector analysis and its application in developing new strategies for enhancing the PA and transmitter design. This will particularly focus on non-linear device characterization and measurement challenges for catering to the needs of 5G communication standards. The workshop will focus on following key areas targeting the demands of 5G applications: (1) Broadband nonlinear measurements with NVNA and high efficiency PA design for handling wideband modulated signals with high crest factor. (2) Non-linear device characterization, modeling and PA design based on non-linear embedding and other novel techniques. (3) New digital schemes and architectures for developing non-linear behavioral model and linearization of broadband PA and wireless transmitters for 5G applications. In addition to the above key areas, this workshop will also address the challenges in developing new digital radio front ends and massive MIMO platforms for high speed data link and throughput. This workshop will bring together some of the leading world experts to present the novel measurement techniques and associated PA as well as linearized transmitter design schemes to cater to the upcoming needs of 5G communication.
IMS 2017
New Developments in Microwave Measurements for Planar Circuits and Components
Organizers:
Matthias Ohlrogge, Fraunhofer IAF
Uwe Arz; Physikalisch-Technische Bundesanstalt (PTB)
Abstract:
High-frequency on-wafer measurement techniques are fundamental prerequisites for many applications in science, engineering and metrology. While reliable planar measurements up to millimetre-wave frequencies are becoming more and more state-of-the-art, the traceability in an industrial characterisation process, planar S-parameter measurements of nano-devices and the extension to frequencies beyond 100 GHz are still open topics to the scientific and industrial community. Therefore the aim of this workshop is to provide an overview of these current research areas and to present future directions in the field of planar on-wafer measurements. The first part of this workshop is therefore related to the fundamental question of how to achieve traceability in planar on-wafer measurements. More specifically, this means we will discuss the characterization and verification process of different error mechanisms in a planar on-wafer environment. The second part of the workshop is linked to the measurement of nano-electronic devices. Since these components are rapidly finding their way into the field of millimetre and sub-millimetre wave frequencies, we are facing even more the difficulty of how to perform reliable RF measurements on such devices. This includes issues such as the impedance mismatch problem or the challenge of probing at nanoscale dimensions. Besides the complexity regarding the measurement of nano-devices, reliable on wafer measurements at sub-millimetre frequencies are nowadays getting increasingly important. At these high frequencies one faces the problem of crosstalk phenomena and excitation of higher order modes. These relevant topics together with future thoughts on how to solve them shall be covered in the third part of this workshop. To summarize the workshop and get a broad feedback on potential future topics we will initiate a round table discussion at the end. At this point everybody will have the opportunity to interact with the speakers more closely than in the short discussions after each talk.
RF to/from Bits: Challenges in High Frequency Mixed Signal Measurements and Design
Organizers:
Jon Martens, Anritsu;
Nuno Carvalho, IT-Universidade de Aveiro
Abstract:
With higher levels of integration and ever higher bandwidth requirements in communications, telemetry and control systems, mixed signal measurements and behaviors in these systems involving data converters are increasingly important. Receiver chains must manage wide bandwidths and not introduce added distortions through data conversion, predistorters must correctly digitize and process transmitter behaviors at sufficient speed with a minimum of added transfer errors, and digital transmitters must control detailed spectral purity requirements. Characterization of systems like these must handle a mixed-domain calibration space and detail a complicated multivariate problem where converter clocks can play an even greater role than do front end local oscillators. This workshop will cover this category from a number of viewpoints to highlight some approaches to distortion management/characterization, managing details of converter behavior and better understanding performance of these complex systems.
Novel 5G Applications of Nonlinear Vector Network Analyzer for Broadband Modulation and Millimeter Wave Characterization
Organizers:
Patrick Roblin, The Ohio State University;
Apolinar Reynoso-Hernandez, CICESE
Abstract:
The world’s thirst for communication keeps on increasing as users are attracted to new broadband services for accessing data on the cloud, video-conferencing, and streaming videos using various user equipment. This growing demand for higher data rates (>=6 Gpbs) is motivating vigorous research activities worldwide on the development of wideband and multiband systems above and below 6 GHz. The fifth generation (5G) of wireless standards are being developed for cellular communication by 3GPP to directly address these issues. This workshop will focus on new 5G applications of nonlinear vector network analyzers (NVNAs) including: (1) Vector signal analysis for measuring with a high dynamic range, modulated signals with very large bandwidth (multiple GHz). (2) The characterization of millimetre transistors which includes the impact of large-signal cyclo-stationary memory effects in CW mm-wave small-signal response. (3) Newly supportive phase references and phase-calibration techniques for NVNAs permitting the full characterization of RF PAs under various wideband and multiband excitations. With the development of these novel measurement techniques, new challenges in behavioral & circuit modeling of devices for broadband modulated multi-harmonic excitations must also be addressed. This includes characterizing and modeling the mutual coupling between the elements of the massive MIMO active antenna array and the associated dynamic load modulation it induces. Also the mixed-signal instrumentation and measurement approaches needed to characterize software defined radio and digital radio front ends for the new 5G communication paradigm will be presented together with the application of D-parameters to mixed-signal integrated solutions for 5G. This workshop will bring together some of the leading world experts in the field to present both these novel measurement techniques and associated emerging behavioral modeling techniques.
Plug and Play S-Parameter Measurements and Models for Broadband Interconnects
Organizers:
Mike Resso, Keysight Technologies;
Heidi Barnes, Keysight Technologies
Abstract:
This workshop will provide an industry perspective on interconnect issues with reference plane placement and the subsequent impact on achieving high quality broadband s-parameter measurements and models. An overview will be provided from the historical challenges of the simple coaxial connector to understanding the latest in low power, high density, high speed interconnects for the Internet-of-Things (IOT). This IOT industry is rapidly moving towards new standards, such as the USB Type-C reversible interconnect that runs at 10Gb/s data rates creating microwave frequencies and is capable of 100 watts of power all in a PCB footprint that is smaller than a single edge launch SMA to PCB connector. Ensuring error free data transmission requires the ability to plug and play s-parameter models of various components for design exploration, turn-on debug, and compliance verification. Measurement calibrations and simulation reference planes need to pay careful attention to the definition and location of the s-parameter reference planes to insure the accuracy when cascaded in a full channel simulation across both time and frequency domains. Adding to the complexity is the high density coupling and crosstalk for signal integrity applications and the extremely low impedances on the power integrity side. This special session will include worldwide expertise in these engineering disciplines as well as academia to provide practical tips and techniques for measuring and modeling interconnects with custom calibration and simulation reference planes.
IMS 2016
Large Signal Network Analysis: From Instrumentation Architectures to Software Applications for Your RF Design Flow Improvement
Organizers:
Tibault Reveyrand, The Ohio State University
Antonio Raffo, University of Ferrara
Abstract:
This workshop focuses on large signal network analysis. This approach, more challenging than small-signal characterization, is a prime importance in the optimized design of RF circuits. The workshop addresses the instrumentation hardware architectures and the software tools that can solve high-efficiency linear amplification on various topologies (envelope tracking, Doherty, Outphasing transmitters,…). Instrumentation down-conversion is based on mixers (VNAs and VSAs), sub-samplers or tracking-and-hold amplifiers. Application tools include the last advancements on compact/behavioral modeling at transistor level but also on the methods to improve efficiency of your RF transmitter design thanks to waveform engineering. RF models and methods accuracy are upgraded by adding low-frequency dynamic characteristics of transistors. Design flow will be presented for a very large set of examples: from instrumentation, to transistors levels characterization (GaAs, GaN) up to complex architectures such as very high power amplifier for base station, Doherty, Outphasing and Varactors. The advantages of the large signal network analysis will be clearly illustrated and demonstrated.
MM-Waves Measurement Needs for 5G
Organizers:
Nuno Carvalho, Instituto de Telecomunicacoes
Jon Martens, Anritsu
Abstract:
5G is the next big step on wireless communications. Several proposals are moving this technology to millimeter wave solutions, which will allow to increase significantly the bandwidth and bitrate levels. Nevertheless not only several transceiver design strategies should be discussed but also new characterization techniques should be adapted for this frequency band. In this workshop several strategies for 5G transceiver design will be addressed first with a group of industry and academic groups presenting their new designs, and will be followed by a strong discussion on characterization, instrumentation and measurement techniques, specially focused on millimeter wave signals that would be used on 5G applications. In this scenario industry and R&D laboratories will discuss this issue carefully.
IMS 2015
Direct Extraction of FET Circuit Models from Microwave and Baseband Large-Signal Measurements for Model-Based Microwave Power Amplifier Design
Organizers:
Patrick Roblin, The Ohio State University
David E. Root, Keysight Technologies
Abstract:
Leveraged by the availability of nonlinear vector network analyzers (NVNA), the efficient extraction of circuit-based FET models including memory effects directly from large-signal microwave measurements is now possible and has been successfully demonstrated. There is now a comprehensive body of work published on this emerging topic. This workshop will bring together many of the world experts in this field to present the results already demonstrated by this new approach and outline the outstanding challenges remaining ahead. This workshop will start with a review of the progress in the field, and include tutorials on key extraction topics. The focus of this workshop is to report on advanced techniques for the extraction and validation of circuit-based device-models using large-signal microwave measurements with NVNAs. Model-based nonlinear embedding design technique that enables efficient power amplifier (PA) designs starting from a desired intrinsic PA mode will also be reviewed as an emerging application.,As wireless communication keeps expanding and various RF front end technologies are competing for these new markets, continuing challenges are arising for the development of circuit-based device models for power microwave field-effect transistors (FET) that are able to predict the device performance under realistic large-signal operating conditions. Specifically, device models must account for the actual device response when the FETs are excited by modulated RF communication signals exhibiting a high peak to average power ratio. Under such conditions some memory effects such as (1) self-heating and (2) traps in GaN HEMTs, which are intermittently activated by high instantaneous voltages, are observed to profoundly modify the device performance at low average power.,Circuit-based device models based on a physical topology remain of great importance as they provide the means to monitor the load-lines at the current-source reference planes in order to verify the transistor’s mode of operation in power amplifiers (PA). They also play an essential role in the promising model-based nonlinear embedding design technique that enables efficient design starting from a desired intrinsic PA mode. However, reasonable, accurate and realistic models are required for successful model-based PA design. Given the high peak to average power ratio of modern RF communication signals, various low-frequency memory effects (self-heating, trapping) are known to be excited by intermittent high instantaneous voltages at peak power. These memory effects can in turn substantially modify the subsequent response of the device under large-signal operation at average power. Much effort has been placed in finding new ways to efficiently characterize and model these effects. This includes direct model extraction from (1) modulated large-signal microwave measurements with NVNAs and (2) various low-frequency large-signal measurement techniques. This workshop will review these various advanced measurement and modeling techniques for the efficient extraction of realistic transistor models as well as present examples of application to power amplifier design.