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The November 2007 conference featured 12 high quality papers on a range of RF and Microwave topics from leading commercial and academic institutions. The best paper prize was awarded to Dominic Fitzpatrick of Cardiff University. Copies of the papers can be downloaded below, free of charge. The event was sponsored by SJ Technologie: www.sjtechnologie.co.uk/
This conference was held on Monday 5th November to Tuesday 6th November 2007 at:
Hotel Elizabeth Rockingham
Rockingham Road
Corby
Northamptonshire
NN17 1AE
Tel. 01536 401348
Fax. 01536 266383
Email. elizabeth.rockingham@elizabethhotels.co.uk
Website. www.elizabethhotels.co.uk/hotel_elizabeth_rockingham.cfm
The Programme Co-ordinator was
Steve Williamson
Principal RF Design Engineer
Anritsu
Rutherford Close
Stevenage
Hertfordshire
SG1 2EF
Tel. 01582 814506
Email. steve.williamson@anritsu.com
Gavin Fisher, Cascade Microtech Europe
Successful on wafer RF characterisation can present some significant challenges. This presentation will discuss the techniques and tools that can be employed to characterise successfully. This will include design for testing, measurement hardware arrangements, calibration, verification and device measurement and post processing.
Roscoe W.S. Harrison, Roke Manor Research Ltd
Roke Manor Research has developed Wavedancer 400, an ultra low power ISM band transceiver integrated circuit (IC). Wavedancer 400 utilises a low cost direct conversion architecture with class leading power consumption and receiver sensitivity. The chip offers two selectable bandwidths in both transmit and receive modes allowing either high data rates or maximum receiver sensitivity. These features mean it is ideally placed for use in a variety of applications such as telemetry, remote location deployment and ranged tagging.
Dominic Fitzpatrick, Cardiff University
The most commonly used method for characterising microwave components is to measure the s-parameters of the device using a Vector Network Analyser. A problem with this method is that the VNAs are essentially narrow band down converters and cannot handle harmonic and distortion products.
By directly measuring the incident and reflected waveforms on the device ports with wide bandwidth samplers and then processing these waveforms, not only can large signal s-parameters be extracted but also harmonic and compression characteristics. The flexibility offered by the direct access to the sampling heads allows for the construction of measurement systems which can, for example, directly measure the multi-port devices with all ports simultaneously excited (such as phased array elements).
This paper describes the basic waveform measurement system developed at Cardiff University, and then some the applications to which this system has been applied including, small and large s-parameter measurement, DC-IV device characterisation, active load-pull including harmonic, and four port antenna match. The potential for 'waveform engineering' and accurate large signal device modelling is described.
Ivan Boshnakov, Aerial Facilities Ltd
In the recent years wide bandgap transistors (SiC MESFETs and GaN HEMTs) have appeared on the market for high power RF/microwave transistors. They offer higher power density and higher voltage operation, which in turn are associated with much lower parasitic capacitances and much higher load-line dynamic resistance, and hence wider bandwidth applications. Of the two kinds the GaN HEMTs offer higher gain performance.
This article compares the performance of a 10W GaAS MESFET which has been very popular for years and a new 10W GaN HEMT by describing the practical design of 10W Class A amplifier stages with the two transistors.
Simon W Day, Phasor Design
The Software Defined Radio (SDR) notion is a radio receiver consisting of antenna, analogue to digital converter (ADC) with filtering, demodulation etc implemented either in software or software configurable logic. In this scheme the performance of the ADC is particularly important and sufficiently large amount of digital processing power may be necessary. However the technology is slowly becoming mature and applications are appearing.
The principal means of disseminating the UK national standards of time and frequency is the MSF signal, which is provided by the National Physical Laboratory. Transmission from Anthorn in Cumbria is 24 hours a day and the carrier frequency is maintained at 60 kHz to within 2 parts in 1012. The basic symbol rate is 10 Symbol/s and so a bandwidth of 10 to 20Hz is required.
The SDR arrangement is particularly well suited to a receiver for the 60kHz MSF time signal. 10Hz low pass filters with good Gaussian pulse performance can be implemented in software, which would otherwise be a little laborious and, in addition, good stability is inherent in the SDR method.
S.V. Potter, EADS Astrium (UK) Ltd
Some communication satellites have an antenna that consists of a fixed parabolic reflector that is fed by an array. Such antenna systems can be programmed to produce a variety of fixed beams in response to traffic demands and can be built so that each array element is fed by a its own high power amplifier. However benefits can accrue if the amplifiers are incorporated in Multiport Power Amplifiers (MPAs). The architecture of an MPA is shown in Figure 1. Ideally all the MPA inputs are divided equally between all amplifiers and there is a one to one correspondence between the MPA feed ports and the MPA array ports. Due to imperfections in the INET and the ONET, and differences between the amplifiers, the ideal behaviour is never realized in practice. To optimize the performance of any manufactured MPA a deliberate offset in the gain and phase shift of each amplifier has to be introduced to compensate for the imperfections introduced by the INET, the ONET and their associated cabling. This paper shows how the RF modelling of an MPA has been performed by computer modelling using the Agilent ADS software.
Liam Devlin, Plextek Ltd
This paper details the design, realisation and measured performance of a set of MMICs for broadband receiver applications. Five different MMICs are described: A 0.5 to 20GHz dual channel limiter, a 2 to 18GHz dual channel Low Noise Amplifier (LNA), a DC to 20GHz dual channel Single Pole Double Throw (SPDT) switch, a 2 to 18GHz upconverter and a companion downconverter. The MMICs can be used to implement a compact, dual channel 2-18GHz receiver and an example of this is also described.
Dr. Stelios Tsitsos, Technological and Educational Institute (T.E.I.) of Serres
The rapid development of today's mobile communication systems has produced a huge number of compact and inexpensive hand-held communication sets. Very small sized filters suitable for GSM, DCS, UMTS and other technologies have been produced by utilising high dielectric constant and low loss ceramic materials. A common problem during the manufacturing process of such components is the considerable amount of time spent during the trimming process to achieve the desired frequency response. An improved design method is presented in this work and can be employed to provide reliable components "straight out of the box".
Computer-aided analysis techniques of ceramic filters have been presented. In this paper an accurate approach for the design of ceramic monoblock filters is presented. This technique makes use of an equivalent circuit as the basic design and tuning tool. This equivalent circuit is based on the extraction of equivalent circuit parameters from first electromagnetic principles and provides an accurate model for the ceramic monoblock structures.
Andrew Wallace, Applied Wave Research Ltd
ACE(tm) automated circuit extraction technology from Applied Wave Research, Inc. (AWR(r)) is an innovative approach to avoid the over dependence of EM analysis as a design tool. ACE software automates modeling of complex interconnect structures defined by paths by assembling their equivalent electrical models on the fly using the very same network representation designers themselves would make use of if they had the time and patience to do so. The simulation of the equivalent circuit is done in a fraction of the time that it would take EM tools to create S-parameters. The speed, accuracy, and parametric nature of ACE software enable engineers to return to real design by exploring design alternatives and changes in seconds. Obviously, EM is still a necessary part of the flow, but the ACE tool enables engineers to once again design rather than analyze, even on many of the most challenging RF/MW designs.
Mark Ashcroft, Fluke Precision Measurements Ltd
In today’s digital world, many established analog techniques are being replaced by modern digital alternatives. Digital modulation is now commonplace, particularly in mobile communications, but traditional analog amplitude and frequency modulation are still in widespread use. Laboratories performing RF calibration report that analog modulation meters and analyzers are a part of their workload that cannot be ignored. When a new RF calibration source was designed, precision analog modulation was included to address this workload. This paper describes the digital signal processing based techniques used to measure its modulated outputs, and explores the challenges in assessing modulation measurement uncertainties and validating the results obtained.
Andy Pienkowski, Innovision Research & Technology Plc
In the world of passive RFID, fast returns on investment in an extremely high volume industry are only possible if testing costs are minimised. This pushes the limits of traditional testers beyond their standard digital and parallel test capability. Reliable techniques must be found, therefore, to adapt standard testers to suit the RFID purpose: such techniques are the subject of this paper.
Francois Bore, Atmel
A high speed ADC that offers good linearity over a range of high frequency inputs is a key component for tomorrow's broadband RF transmitters using high Intermediate Frequency (IF) architectures.
New architectures for ADC allow now to reach performances which were barely conceivable a few years ago. Broadband IF Sampling ADC architectures are today capable of directly digitizing wideband signals around second or first IF zones while keeping excellent linearity performance, paving the way to Software Radio. The architectural shift to broadband data conversion leads to increased ADC sampling rate thus creating new challeges in design, package and test methodology.
A 10-bit 2.2Gsps ADC has been developed based on a 75GHz SiGe HBT process, including special features for better industrial test coverage.
Key issues for design, test and circuit specification, altogether with characterization results are presented and analyzed.
We would like to thank the following company for sponsoring this event…
SJ Technologie http://www.sjtechnology.co.uk/
