Armms RF and Microwave Society
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Conferences

Next Conference:

Monday 7th November to Tuesday 8th November 2016 at Wyboston Lakes, Bedfordshire

Bookings for the November meeting are now open.

The November 2016 meeting returns to Wyboston Lakes. It will commence with lunch at 12.30pm on the Monday and will finish at around 3:30pm on the Tuesday.

Young Engineer Sponsorship: The ARMMS RF & Microwave Society offers sponsorship to young engineers (28 or below) who have papers accepted for presentation. Sponsorship is £100 cash plus free attendance (including conference dinner and overnight accommodation). Potential candidates should identify themselves as eligible at time of submission and state their date of birth. This offer is limited to a maximum of 2 places per meeting.

Best Paper Award: The Steve Evans-Pughe prize is awarded to the best presenter at each meeting. The award is £200 for the best paper and £50 for the runner-up. The prize is sponsored by NI.

If you are interested in submitting a paper for presentation at this conference, please contact the technical coordinator (details below). Papers currently listed below are those already accepted. The deadline for submissions is September 19th. For all other enquiries please email enquiries@armms.org

VENUE

Wyboston Lakes
Great North Road
Wyboston
Bedfordshire
MK44 3AL

Tel0333 7007 667
Emailsales@wybostonlakes.co.uk
Webhttp://www.wybostonlakes.co.uk/

PROGRAMME CO-ORDINATOR

Chris Watts
Golledge

Tel+44 (0)1460 256 122
Emailc.watts@golledge.com

PAPERS

24GHz Radar Technology Enabling Next Generation Sensors

Mike Mullins
Analog Devices

A presentation showing how Multi-Channel 24GHz Radar Technology is finding a home in applications beyond Automotive.

This technology also enables Smarter Sensing in both traditional & emerging Commercial & Industrial applications.

The presentation provides an overview of radar technology and shows how a full signal chain radar solution can be used in several applications.


An Overview of WLAN: System Requirements and Practical Devices for Mobile WiFi

Dr Apostolos Samelis
Skyworks

The new 802.11ac standard and the emerging 802.11ax WLAN standard are requiring the development of extremely linear power amplifiers. These standards also require the PA to operate with crest factors of 10dB, with RF bursts up to 5ms long, while delivering average powers of up to 500mW. This poses challenging requirements on the performance of the wireless devices. In addition to the extreme linearity requirements, the power amplifier at the end of the transmit path suffers from slow electro-thermal transients as it is responding to the WLAN bursts. This paper reviews the requirements of WLAN devices at both the system and physical level. Packaging and semiconductor technologies used in state of the art WLAN power amplifiers will be discussed, and various IC implementations will be presented.


An Overview of WLAN: System Requirements and Practical Devices for Mobile WiFi

Apostolos Samelis and Darcy Poulin
Skyworks Solutions Inc

The new 802.11ac standard and the emerging 802.11ax WLAN standard are requiring the development of extremely linear power amplifiers. These standards also require the PA to operate with crest factors of 10dB, with RF bursts up to 5ms long, while delivering average powers of up to 500mW. This poses challenging requirements on the performance of the wireless devices. In addition to the extreme linearity requirements, the power amplifier at the end of the transmit path suffers from slow electro-thermal transients as it is responding to the WLAN bursts. This paper reviews the requirements of WLAN devices at both the system and physical level. Packaging and semiconductor technologies used in state of the art WLAN power amplifiers will be discussed, and various IC implementations will be presented.


An X-band GaN PA MMIC for Phased Array Radar Applications

Liam Devlin and Stuart Glynn
Plextek RFI

Active phased array radars require numerous Power Amplifiers (PAs), which must be small, efficient and low-cost. This paper describes an X-band PA MMIC that covers 9 to 11.5GHz and satisfies these requirements. It has an output power of 7W (38.5dBm) from a 29dBm drive with a Power Added Efficiency (PAE) of 42%. The design was realized on the 0.25µm gate length GaN on SiC process of UMS (GH25) using Keysight’s ADS 2015.  The die size is just 1.5mm x 2mm, which means that around 2,300 PAs can be fabricated on a single 4” diameter wafer.


Assessing the RF Performance of Medical Implant Antennas

Yomna El-Saboni
University of Belfast
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Assessing the RF Performance of Medical Implant Antennas

Yomna ElSaboni, Matthew K. Magill, Gareth A. Conway, William G. Scanlon
Queen's University, Belfast

Active implantable medical devices are becoming increasingly more popular as new applications are developed to improve patient treatment and care. Many implant applications are utilising RF techniques to provide communication and control for electronic devices within the human body, especially at frequencies between 400 MHz and 2.45 GHz. Physical size is an obvious and important concern in the design of implant devices and this means that there is a need for innovation in the design of miniaturised antenna solutions that have adequate performance in the challenging human body environment. While there is a role for simulation and modelling, the test and characterisation of these innovative implant antennas is another crucial factor in the development of these medical systems. There are many issues to take into consideration that can affect the results obtained when testing miniaturized implant antennas. For example, the local environment surrounding the antenna affects both impedance matching and radiation performance and so the test environment, typically a tissue equivalent phantom is extremely important. Additionally, in practice the close proximity of the body tissues affects the antenna’s radiation performance and introduces significant losses into the reactive near fields that are associated with resonant antennas. This highlights not only the importance of accurate phantom modelling and the effect of antenna coating material, but also the source feeding techniques and characterizing its sensitivity inside the phantom.

This paper will specifically illustrate the challenges faced when conducting radiation efficiency measurements for implantable antennas when they are inserted inside a tissue representative human body phantom. Our objective is to highlight the disturbance caused by the necessary feed cable and demonstrate techniques to minimize it. Only standardized antennas were used and the measurements were conducted using a novel reverberation chamber approach to obtain highly accurate results at extremely low radiation efficiencies associated with these applications. In order to gain a better understanding, the experiment was repeated with different antennas and phantom set ups and the results clearly illustrate the factors that need to be considered when assessing the RF performance of medical implant antennas.


High Power GaN Amplifier for High Efficiency Applications

Avtar Virdee, Bal Virdee, Kafil Ahmed
Microwave Technology Ltd

The design and measured results of a single stage S-Band high-efficiency GaN-HEMT power amplifier is presented that uses Class-F harmonic processing technique to shape the current and voltage waveforms to improve the amplifiers efficiency performance. The GaN-HEMT device employed is a commercial off the shelf device that is designed for high voltage operation. The fabricated GaN-HEMT power amplifier operating under continuous wave mode achieved a nominal gain of 18 dB with an output power of 130 Watts, a drain efficiency of 73%, and power added efficiency (PAE) of 64% across 2.35 to 2.55 GHz.


Measuring Electro-luminescence and Photosensitivity of Trap Sites in GaN Devices

M.A.Casbon, T. Brazzini, P. J. Tasker, M. Uren, M. Kuball
University of Cardiff

Here we present a system allowing simultaneous measurement of the RF and optical behaviour of on-wafer devices, which permits  Fully Active Harmonic Load-Pull techniques to be employed while either observing optical phenomena such as Electroluminescence, or applying optical stimuli for trapping investigations. Full access to the backside of the wafer is achieved, allowing measurements on devices with source coupled field plates or air bridges, which normally obscure the gate region. Electroluminescence can be observed with an ultra-low light camera or a spectrometer. Previously it has been shown that traps in GaN devices can react to light at 385nm, here the wavelength sensitivity is investigated.  The test device was a GaN on silicon carbide HFET.


State of the Art Gyrotron Simulations and Features Needed to Make Them

Jonathan Smith
Tech-X UK

Computation has long played a role in the design of vacuum electronic devices due to the need to handle arbitrary geometry and the complicated particle/surface interactions that are often critical to their performance.  Here, we present a powerful multidimensional code applicable to a wide range of vacuum electronic applications. We explore critical algorithmic advances from the last 10 years that enable state of the art simulation studies, and place these in the context of magnetrons, klystrons, gyrotrons and travelling wave tubes and passive cavities. We show the new techniques to understand the dynamics of particles in the presence of high power RF fields, their interactions with walls and the ability to handle electrically very large problems.

We show how "hot test" simulation results of the high order modes found in fusion gyrotrons increase understanding of operational showstoppers.


The Design of High Performance L-band GaN PAs Using Commercially Available Discrete Transistors

Robert Smith
Plextek RFI

This paper describes the design and evaluation of a four different single stage L-Band GaN Power Amplifiers (PAs) using commercially available, low-cost packaged transistors. Two of the transistors are housed in SMT plastic packages and two in metal-based ceramic packages. The transistors are commercially available parts from Qorvo realised on a high voltage 0.25 µm GaN process. All four amplifiers have been optimised for the 0.96 to 1.215 GHz band and are designed to operate in CW or pulsed mode. The plastic packaged parts offer output powers of 11 W and 14 W with corresponding PAEs of 65% and 55%. The ceramic packaged parts offer higher output power levels of 59 W and 125 W with PAEs of 60% and 70% respectively. This paper describes the design, realisation and measurement of the four PAs, which demonstrate high performance using cost-effective commercially available transistors.


The Inverted E: A Doubly-shorted F Antenna for Near-field Sensing Applications

Oliver Collis
Sylatech Ltd
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The RF Modelling of a Ku-band Multi-port Amplifier

Peter James
Airbus Defence and Space (UK) Ltd

The object of this paper is to describe the RF modelling of a Ku-band MPA. This has been performed to compare against the measured results of an MPA demonstrator that has been designed, constructed and tested at Airbus. It will describe the modelling process and show some predicted and measured results. The model may then be used for predictions in the future prior to the construction and measurement of a real flight MPA. In addition it becomes a generic model from which future models may be based upon.



EXHIBITION

Companies booking two or more delegate places are able to take part in the commercial exhibition that accompanies the conference. Please note: there is a maximum of 20 exhibition tables at each meeting, these are offered on a first come basis. Booking two delegate places does not guarantee an exhibition space, please email exhibition@armms.org to check availability and reserve and exhibition space.


SPONSORSHIP

The Society would like to thank National Instruments for sponsoring the November 2016 meeting:

 


CALL FOR PAPERS

Contributions are invited with an emphasis on RF and microwave design, research, testing and associated subjects. An oral presentation will be made at the meeting and a written paper will be required for publication in the society digest, which is distributed to delegates at the meeting. Prospective speakers are requested to submit a title and a short abstract to the technical coordinator (see above) as soon as possible.

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