Metrology Developments for Future Wireless Technologies
Emerging Wireless Technologies have an impact on nowadays microwave characterization technologies, the change in paradigm from analog to digital and from RF to DC, has a strong impact in the way nonlinear microwave characterization is seen. In this talk a general overview of these technologies is presented, focusing on Software Defined Radio and on RF-DC converters for Wireless Power Transmission, and despite its apparent differences, nonlinear characterization will be presented as an integrated view on how to model and how to characterize those components.
- Prof. Nuno Borges Carvalho,
Instituto de Telecomunicacoes, Universidade de Aveiro, 3810-193 Aveiro, Portugal
Tel: +351 23 4377900
High-Frequency Measurements of Dielectric Substrate Materials
Material manufacturers are developing new, high-performance substrate materials in order to meet the specifications of new applications that operate over wider and wider frequencies. In order for engineers to select the most appropriate material to incorporate into microwave devices, the electrical properties of the substrate, namely the relative permittivity and loss tangent, must be accurately measured, sometimes as a function of frequency, temperature and even humidity. However, there are hundreds of measurement methods published in the literature and selecting the proper technique can be daunting. In this lecture, we overview both transmission-line and resonant techniques for measuring the relative permittivity and loss tangent of dielectric substrates such as printed-circuit boards, printed-wiring boards and ceramic substrates over the frequency range of 1 to 100 GHz. In the area of transmission-line measurements, we outline how to perform broadband on-wafer material measurements using planar structures such as coplanar waveguides and microstrip transmission lines. Next, we overview three resonant measurement methods: the split-cylinder, split-post and Fabry-Perot resonators. These three measurement techniques are increasingly being used by industry to accurately characterize substrate materials at microwave and millimeter-wave frequencies and represent the state of the art in nondestructive materials testing. The lecture concludes with a discussion of each method's advantages and limitations and with some final remarks about the future direction of high-frequency material measurements.
- Prof. Michael D. Janezic,
Electromagnetic Properties of Materials Project, National Institute of Standards and Technology, 325 Broadway MS 818.01F, Boulder, CO 80305
Tel: +1 303 497 3656
Fax: +1 303 497 3970
Microwave fiber-optic links: Design and measurement issues
Optical fibre is an excellent transmission medium - it has very low loss and very large bandwidth (especially when compared with microwave transmission media). In addition, it is possible to modulate light at several tens of GHz and then recover that modulation. Hence there has been much interest in the use of optical fibre for the transmission and processing of RF signals.
In the first part of the talk, some of the basic design issues for analogue links will be discussed. In particular, the effect of component-to-component interaction on small-signal, large-signal and noise performance will be considered. It will be seen that it is useful to be able to model and measure the "microwave characteristics" of optoelectronic and optical components. In the second part of the talk, various techniques for the measurement of high-speed lightwave components will be outlined. The emphasis will be on extending microwave network analyser techniques to these devices. Issues associated with polarization effects, optical cavity resonances and nonlinearity will be discussed in some detail.
- Prof. Stavros Iezekiel,
Department of Electrical and Computer Engineering, University of Cyprus, 75 Kallipoleos Avenue, P.O. Box 20537, 1678 Nicosia, Cyprus
Tel: + 357 22892190
Fax: + 357 22892260
Office: 111 Green Park
Evaluating errors and uncertainties in RF & microwave measurements
This talk gives an overview of the principles and processes involved in dealing with errors in measurements, particularly at RF and microwave frequencies. The talk shows how the concept of uncertainty can be used to quantify the effects of errors that occur during measurements. The methods used to evaluate and express uncertainty are described and illustrated with some simple practical examples. The purpose of this talk is to enlighten rather than mystify the subject of dealing with error and uncertainty in measurement.
- Prof. Nick M. Ridler,
Principal Research Scientist Electromagnetics Team, National Physical Laboratory, Hampton Road, Teddington, Middlesex, TW11 0LW, United Kingdom
Tel: +44 (0) 20 8943 7116
All you need to know about RF and microwave coax connectors but were afraid to ask
The humble coaxial connector has been a regular player in the high frequency electronics industry for the past fifty years or more. But it is this apparent familiarity, and apparent simplicity, that often leads to misunderstandings and mistakes with the use of connectors. This talk will give a review of coax connectors with an emphasis on how to get the most from any given connector. The talk begins with an historical overview of the evolution of the coax connector right up to the present day. The dos and don'ts of using connectors will also be addressed and how to select the best connector for a given application. Finally, some tips will be given on how to keep connectors in good health and how to ensure long connector life.
- Prof. Nick M. Ridler,
Principal Research Scientist Electromagnetics Team, National Physical Laboratory, Hampton Road, Teddington, Middlesex, TW11 0LW, United Kingdom
Tel: +44 (0) 20 8943 7116
RF I-V Waveform Measurement and Engineering - the unifying link between transistor technology, circuit design and system performance
Microwave power amplifier performance, output power, conversion efficiency and linearity, etc., is significantly influenced by the terminal voltage and current time varying waveforms that develop at the transistor terminals; terminal waveforms are the unifying theoretical link between transistor technology, circuit design and system performance. Thus waveform engineering should be a major objective driving the power amplifiers design flow. However, in practice power amplifier design, while waveform engineering may be a guiding principle, the lack of appropriate RF waveform measurements tools has hindered its direct application at microwave frequencies. However, the past 10 years has seen the development of a number of RF characterization systems capable of measuring RF voltage and current waveforms. Coupling such systems with impedance control hardware also enables experimental control (Engineering) of these terminal RF waveforms during measurements; thus providing a practical RF Waveform Measurement & Engineering solution. This lecture will discuss these emerging systems and show they are now finally enabling practical waveform engineering to be directly undertaken within the power amplifier design flow. Design support can involve either direct utilization of the measurement system in the design investigation/evaluation loop, or indirect use by providing CAD accessible datasets.
- Prof. Paul J Tasker,
Cardiff School of Engineering, Cardiff University, Queen's Buildings, 5 The Parade, Newport Road, Cardiff CF24 3AA
Tel:+44 (0)29 2087 4423
Fax:+44 (0)29 2087 4939
For more information about the Distinguished Microwave Lecturer program, click
here.
Jose Carlos Pedro : Distinguished Microwave Lecturer (2014-2016)
The Wonderful World of Nonlinearity: Modeling and Characterization of RF and Microwave Circuits
Despite the many studies that have been undertaken to understand the wonderful world of nonlinearity, most undergraduate electrical engineering programs are still confined to linear analysis and design tools. As a result, the vast majority of microwave designers still cannot profit from the significant technological advancements that have been made in nonlinear circuit simulation, active device modeling and new instrumentation for performance verification. So, they tend to conduct their designs relying on experience, empirical concepts, and many trial and error iterations in the lab.
This talk will reveal the ubiquitous presence of nonlinearity in all RF and microwave circuits and the recent efforts made to understand, model, predict, and measure its diverse manifestations. We aim to bring microwave engineers' attention to newly available techniques, and attract researchers to pursue further studies on this scientifically exciting topic.
Starting with some elementary properties of nonlinear circuits (like nonlinear signal distortion, harmonic generation, frequency conversion and spectral regrowth), we will show that nonlinearity is present in all wireless circuits, either to perform a desired signal operation or as unintentional distortion. In this way, we will show how oscillators, modulators or mixers could not exist without nonlinearity, while power-amplifier designers struggle to get rid of its distortion effects.
After this theoretical overview, we will introduce some recent advancements in nonlinear microwave circuit analysis tools and illustrate different types of models that are currently being used to represent and predict device, circuit, and system performance. Finally, we will focus the talk on the key metrics that are used to characterize nonlinear behavior, as well as newly developed lab instruments and their ability to assess device performance.
- Prof. Jose Carlos Pedro,
Instituto de Telecomunicacoes - Universidade de Aveiro, Portugal
Tel +351 234377900
Dominique Schreurs : Distinguished Microwave Lecturer (2012-2014)
Towards Greener Smartphones with Microwave Measurements
Today's smartphone handsets offer a wide range of functions (phone, GPS, Bluetooth, WiFi, .) to customers, although are still perceived as expensive and energy consuming (requiring a daily recharge). The aim of this talk is to show how microwave measurements impact smartphone design. By optimally engineering the type of measurements made before and after design (linear, nonlinear, loadpull, modulation, .), the efficiency of the design process not only increases, but tougher specifications such as smaller form factor and lower energy consumption can be met more easily. This observation is especially valid in the design of green multi-mode wireless radios, due to the delicate balance between energy efficiency and linearity (that is, cross talk between channels).
The didactic level of this talk will be adapted to the background of the audience.
- Prof. Dominique Schreurs,
K.U.Leuven, Div. ESAT-TELEMIC, Kasteelpark Arenberg 10, B-3001 Leuven, Belgium
Tel +32 16-321821
Andrea Ferrero : Distinguished Microwave Lecturer (2010-2012)
Multiport Vector Network Analyzer: From the beginning to modern signal integrity applications
With the recent digital systems and circuits outstanding increase in speed and complexity, multiport characterization at microwaves and millimeter waves is experiencing an impressive growth in demand and importance. Today the application of multiport techniques is shifting from typical microwave applications to signal integrity in computer technologies.
The importance of the VNA design as well as the calibration techniques which guarantees the accuracy is a must when low level crosstalk needs to be measured or when differential S-parameters are used.
The talk will present the most modern solutions for multiport measurements at microwave frequencies as well as their advance calibration techniques.
In particular the following topics will be given with the focus on multiport application:
- Single-Ended and Differential S-Parameters Review
- VNA Architectures
- Error Models and Calibration Techniques
- Accuracy of Multiport Measurements
- Interconnection and Fixture Design for Multiport Measurement
- On-Wafer Design of Multiport Standards
- Prof. Andrea Ferrero,
Dip. Elettronica , Politecnico di Torino, Duca degli Abruzzi 24, 10124, Torino, Italy
Tel:+390115644082
Fax:+390115644099
Paul J Tasker : Distinguished Microwave Lecturer (2008-2010)
RF I-V Waveform Measurement and Engineering - the unifying link between transistor technology, circuit design and system performance
Microwave power amplifier performance, output power, conversion efficiency and linearity, etc., is significantly influenced by the terminal voltage and current time varying waveforms that develop at the transistor terminals; terminal waveforms are the unifying theoretical link between transistor technology, circuit design and system performance. Thus waveform engineering should be a major objective driving the power amplifiers design flow. However, in practice power amplifier design, while waveform engineering may be a guiding principle, the lack of appropriate RF waveform measurements tools has hindered its direct application at microwave frequencies. However, the past 10 years has seen the development of a number of RF characterization systems capable of measuring RF voltage and current waveforms. Coupling such systems with impedance control hardware also enables experimental control (Engineering) of these terminal RF waveforms during measurements; thus providing a practical RF Waveform Measurement & Engineering solution. This lecture will discuss these emerging systems and show they are now finally enabling practical waveform engineering to be directly undertaken within the power amplifier design flow. Design support can involve either direct utilization of the measurement system in the design investigation/evaluation loop, or indirect use by providing CAD accessible datasets.
- Prof. Paul J Tasker,
Cardiff School of Engineering, Cardiff University, Queen's Buildings, 5 The Parade, Newport Road, Cardiff CF24 3AA
Tel:+44 (0)29 2087 4423
Fax:+44 (0)29 2087 4939
