Application:

Antennas

Software:

NI AWR Design Environment

Microwave Office

AXIEM

Company Profi leTyndall National Institute is one of Europe’s leading research centers in information and

communications technology (ICT) and is also the largest research facility of its type in

Ireland. Tyndall excels in four core research areas; photonics, microsystems, micro/

nanoelectronics, and theory modeling/design. Specifi c to the latter, the Wireless Sensor

Networks (WSN) Group is developing next-generation wireless sensor network

technology for Science Foundation Ireland’s world leading Connect Centre for Future

Networks (connectcentre.ie). As part of this research, Dr. John Buckley is developing

antennas for wearable Internet of Things (IoT) applications.

The Design ChallengeThe design of wearable IoT wireless sensor devices presents several design challenges

specifi c to the antenna. In particular, the integration of the antenna into the overall IoT

solution must fi t into a tight footprint (ie, limited space). Also, when in its “wearable”

confi guration, the presence of the body can greatly infl uence the antenna performance.

Electromagnetic (EM) modeling is therefore generally required to analyze and optimize

on-body antenna performance. However, EM modeling using analysis methods such as

fi nite element method (FEM) and method of moments (MoM) requires signifi cant model

complexity and computation time. Therefore, a key challenge of the work was to quickly

develop accurate circuit models in order to effi ciently analyze “wearable” antennas.

The SolutionThe WSN Group developed a model of an antenna in close proximity to the human body.

After evaluating many types of RF simulation software, it was found that NI AWR Design

Environment, specifi cally Microwave Offi ce circuit design software was perfectly suited

for this work. It helped the design team arrive at optimal solutions quickly and in a

productive manner and the optimization features in the

software enabled fast and effi cient determination and

verifi cation of the equivalent circuit parameters. (Note: A

comprehensive review of this work effort is described in

the Institution of Engineering and Technology (IET)

Microwaves, Antennas & Propagation Journal publication1.)

Related to the antenna model developed by WSN, it

provided for an accurate estimation of the total

impedance variation of the antenna across the human

body. One advantage of the model is that it can be

analyzed in seconds versus the hours required of full

FEM EM analysis. This approach results in faster

development times for IoT devices. The model also

provides intuition to the designer as to the antenna

behavior and antenna-body interaction, especially

important for wearable IoT applications.

Success Story

Tyndall National Institute Designs Wearable IoT Antennas With NI AWR Software

‘‘ The use of NI AWR Design

Environment over the past

decade has been invaluable

in developing state-of-the-art

wireless sensor technology

and has also enabled us to

teach the next generation of

microwave engineers. Trust

in the simulation accuracy,

turnaround in technical

support, and the full team of

NI AWR software experts are

the key reasons we continue

to use the products.’’– Dr. John Buckley

Staff Researcher

Tyndall National Institute

tyndall.ie

433 MHz antenna prototype.

ni.com/awr

The Group selected NI AWR Design Environment for this complex antenna design task not only because of its suitability for the project at

hand but also because of the institutes familiarity and prior use of the software for a wide range of RF circuit designs, ranging from

impedance-matching circuits, to baluns, fi lters, resonators, and more. Last but by no means least, the NI AWR Design Environment

software platform was also successfully employed for equivalent-circuit modeling of antennas and load-pull analysis for antenna

impedance-matching networks (Figure 1).

Why NI AWR Design EnvironmentMany reasons supported Tyndall National Institute’s selection of NI AWR Design Environment for the project at hand. A few key

reasons include:

■ NI AWR software’s simulation accuracy and speed

■ Excellent correlation between simulated vs. measured data

■ Exceptional training materials and video tutorials available

■ Outstanding technical support

■ Decade-long experience using the software

■ Robustness and stability of the software tools

In addition to research and development, the institute is also a teaching facility. A signifi cant challenge on this front is the ability to get

students up to speed in RF and microwave circuit simulation in a reasonable amount of time. NI AWR software has continued to be quick for

the students to learn as well as tool they enjoy using. From their fi rst introduction to using the simulator, they can very quickly learn how to

create and simulate RF and microwave circuits using the available documentation and example projects. In a matter of minutes, they are up

and running and they don’t have to invest weeks in learning the software before they can run simulations and produce accurate results.

References

[1] J. L. Buckley, K. G. McCarthy, D. Gaetano, L. Loizou, B. O’Flynn, and C. O’Mathuna,

“Design of a compact, fully-autonomous 433 MHz tunable antenna for wearable wireless

sensor applications,” IET Microwaves, Antennas & Propagation, vol. 11, pp. 548-556, 2

©2017 National Instruments. All rights reserved. AWR, AWR Design Environment, AXIEM, Microwave Offi ce, National Instruments, NI, and ni.com are trademarks of National Instruments. Other product and company names listed are trademarks or trade names of their respective companies. SS-M-TYND-2017.9.26

Figure 1: Equivalent circuit of the antenna prototype showing a good match between measured vs. simulated results.

This work is supported by a research

grant from Science Foundation

Ireland (SFI) and is co-funded under

the European Regional Development

Fund under Grant Number 13/

RC/2077.