Printed and reconfigurable microwave electronic circuits on flexible substrates

Lead Research Organisation: University of Surrey
Department Name: ATI Electronics

Abstract

Increasingly there is a demand for high speed digital communication and interconnectivity of devices. The internet of things, which could be defined as a large collection of devices connected and communicating with each other for useful purposes, will require much more bandwidth then is currently available. In order to resolve this problem higher frequencies and new ways of using bandwidth will be needed.

This project aims to develop new inexpensive devices for use in the internet of things. These may include printable antennas based on nanomaterial inks, low temperature or solution processed transistors and the creation of devices on flexible substrates. The ability to reconfigure frequency in the device, that is to change frequency or direction of the beam, will also be investigated. This property would allow much more efficient use of the spectrum and specialist applications such as scanners on automated cars.
In order to achieve these goals devices will need achieve higher frequencies then previously reached. Currently this would be either in the 15GHz or 30GHz range.

There many potential benefits and applications associated with the development of high frequency mass producible devices. These could include automated detection systems in fields set up to monitor soil or crop conditions. Numerous drones could deliver parcels via a parcel delivery services. Connection of sensors in healthcare could provide information on patients which would otherwise be unknown to doctors. Automated cars could also use these frequency bands for scanning terrain in front of them or communication with or oncoming traffic at junctions.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/N509383/1 01/10/2015 30/09/2020
1775112 Studentship EP/N509383/1 01/07/2016 30/06/2019 Kaspar Martin Snashall
 
Description Through this research we have developed printable and flexible switches for use in antenna. These switches can be printed from an inkjet printer similar to those in offices or in the home. We have demonstrated that these switches can be used to change the frequency of a dipole antenna which could have applications in the internet of things (IOT) or 5G communications. These switches currently operate under 6 GHz but we have plans to increase their frequency in the future to our desired 15-30 GHz. We are also currently studying the switches stability over time and hoping to find out if they are stable over long periods or in various weather conditions which could lead to their use in commercial products. We are planning to use these switches in many more devices such as phased array antenna and hope to publish shortly.
Through the research we have also studied the stability of Indium Arsenide (InAs) nanowires. These semiconducting nanowires were initially thought to be a good candidate for radio frequency (RF) printed switches, however we have found that they are particularly sensitive to air and moisture. This causes devices made with these nanowires to decay quickly preventing their use in printed electronics without improvements in coating technologies. We studied their decay in a number of different environments and have attempted methods to improve their stability.
We have found that printed RF electronics can be particularly difficult to measure in situ due to their flexibility which effects connections to the device. Currently there are no effective techniques for accurately measuring the RF electronics on very flexible thin substrates. We currently looking at methods to help improve their measurement accuracy. If the measurement accuracy can be improved then the stability of RF devices can be studied in more detail.
Exploitation Route We have developed a technique for fabricating printable radio frequency switches and have for the first time measured these switches with reasonable accuracy. It is hoped that the measurements and models may be used by other researchers to simulated or create new devices using these switches. This could lead to new flexible device design which were not previously achievable.
The stability of Indium Arsenide nanowires remains a problem and researchers should look at new ways of encapsulating these devices if they are to be used in flexible radio frequency electronics. It is hoped that since stability has been pointed out as an issue then researchers might consider this when designing or investigating other flexible devices.
Measurements of flexible radio frequency devices remains a challenge and it is hoped that a discussion can be opened up on this topic and new methods for their accurate measurement found which will facilitate their eventual use in commercial products.
Sectors Aerospace, Defence and Marine,Digital/Communication/Information Technologies (including Software),Electronics