Autonomous Wideband Adaptive

Multifunctional Antenna

Bringing Innovation to Military Communication

Systems

Presented by

Prof. Amit Mehta

Swansea University, UK

a.mehta@swansea.ac.uk

1

Layout

5G and IoT

Needs of Military communications

Adaptive Antennas (AA)

Case studies and applications

Conclusion

2

Rapid evolving communications

3

3G – Speech 4G – See5G – Touch

[Ref: Ericsson]

Exponential increase- devices interconnected

4

[Ref: Ericsson]

Internet of Things(IoT) / Smart City

5[Ref: NEC]

Internet of Military Things

6Base operations• situational awareness • boundary surveillance including harbour•energy management, etc

[Ref: cybercodetech]

Core component – connectivity

7[Ref: CSIS]

Military connectivity problem: much more severe than civilian

• Weak electromagnetic environments

• Jamming / EM Clutter / interference /Multipath

• Overheads of encryption

• Spectrum efficiency - Full sustained HD

• SWaP & Wide band operations

• Longer battery times and device ranges

• Autonomous system operations

8

Current antennas-majority

9

Restrictions of Omni antennas

• Transmit in all directions – enemy knows

• Multipath serious issues – communications ceases

• Power waste – battery loading

• Lower digital data rates

• Smaller ranges

• Interference-lower capacity

• More nodes / area required in sensor networks: Costly

• No axial patterns

• Limited bandwidth

10

Solution: Adaptive Antennas (AA)

Transmit in direction of interest only

High gain, longer ranges & lower transmit power

Multipath mitigation

Jamming avoidance

High throughput

11[Ref: Balanis]

Achieving Pattern Adaptability

• Phased array antennas

• Single element based systems

Phase Shifters

Antennas

ϕ ϕ ϕ ϕ

Power Distribution network

RF Source

Radiation

beam

RF Switch

RF Source

Antenna

Radiation

beam

12[Ref: Balanis]

Array vs single element (GNSS L1 band) – satellite navigation

Array Single element

16 element – large area size, 0.65 m2 One element - .2 m2 (4 times smaller)

Cost - £1000 Cost – £ 50 (20 times cheaper)

Weight 3x gms Weight x gms (3 times lighter)

Total RF loss 10 dB (feeding and phase shifters)

RF loss (3 dB) (over 75 % lower RF loss)

Complex signal processing – more power required

Simple and low power required

Big funding push to come up new innovative single element pattern adaptive designs

13

Initial academic work

• Prof. Mehta 2002 – UK

– Department of Health

• University of Illinois, USA around same time

– NASA project for distributed sensors for satellite applications

• University of California, USA 2005

– DARPA project

14

1515

2. A Mehta, D. Mirshekar-Syahkal and H. Nakano, “Beam adaptive single arm rectangular spiral antenna with switches,”

Microwaves, Antennas and Propagation, IEE Proceedings , vol.153, no.1, pp.13,18, Feb. 2006.

Shorted spiral antenna with four switches. Prototype shorted spiral for switching case 8 θmax and max and for sixteen switching cases

First major papers:

4 Shorting

switches

1

2

3

4O`

4

3 2 1

MEMS

Shorted – Hard wired

4 Shorting

switches

1

2

3

4O`

4

3 2 1

MEMS

Shorted – Hard wiredhard wired

Four shorting

pins

1. A. Mehta and D. Mirshekar-Syahkal, “Spiral antenna with adaptive radiation pattern under electronic control,” Antennas and

Propagation Society International Symposium, IEEE , vol. 1, pp. 843-846, 20-25 June, 2004.

16

And

3. Reconfigurable Scan-Beam Single-Arm Spiral Antenna Integrated With RF-MEMS Switches by Flaviis et al, IEEE Trans.,

Antennas Propagation Vol. 54, NO. 2, February 2006, pp. 455-463

Reconfigurable single-arm rectangular spiral antenna

integrated with four RF-MEMS switches.

Maximum beam direction in both

elevation and azimuth angles.

4. Integration of packaged RF MEMS switches with radiation pattern reconfigurable square spiral micro-strip

antennas by Bernhard et al , IEEE Trans., Antennas Propagation Vol. 54, NO. 2, February 2006, pp. 464-469

Case study: UK MoD funded workJuly 15 - Jan17

• Aims– Fully autonomous intelligent beam steering

system for locking on the strongest signal arrival direction

– Real time link optimization

– RF Switch based, cheap and fast (100 nanosecond)

– User don’t have to do anything

– Operating stack not disturbed: os independent

– Conformal

17

System architecture

18

Beam - steering in 4 quadrants

Directivity 7.81dBiat 2.45GHz

19

Laboratory measurements

Turn table

70cm

Horn antenna

AC

D

B

1.3m

HSLA beam due to A

Multipath signals

A C

D

B

Touch screen

(a). HSLA and Raspberry Pi

Switch control voltages

Power supply

WiFi Adaptor

(b). Raspberry Pi

(c). Experimental set-up 20

Transmitter

Interference

HSLA

Line of sight transmission and interference

Transmitter power: -27 dBm

HSLA gain: 8.94 dBi

Monopole Gain: 3 dBi

0 5 10 15 20

0

1

2

3

4

5

6

Magnitude of Interference (dBm)

Th

rou

gh

pu

t (M

bp

s)

HSLA Monopole Antenna

Monopole

antenna

TransmitterInterference

Test case outputs

• Intelligent link adaptation based on dynamic changing parameter-real time

• Autonomous system

• No disturbance with existing communications

• Future work: Power transmit and direction dynamic: Tx only in direction and to a fixed distance

22

Application - Satellite IoT Tracking

Semi-doughnut beam points high gain in right look up angles, lower EIRP / null other directionsAdjust pattern autonomously and continuously - accordingly to the look up angle

23

Application – jamming avoidance

24

3D pattern of patch antenna (Shell 50 cm)

Frequency: 2.45 GHz

Gain: 4.39 dBi

Beam steering Shell 50 cm)

Frequency: 2.45 GHz

Gain: 10.7 dBi

Application: Autonomous UAV swarm

25Working together: Each drone a sensor giving cue to each otherWorking independent or any other combination

Base station cellular architecture Autonomously Adapt to environmentBeam steering, jamming avoidance & auto power control would play important role

[Ref: US Airforce]

Application-last mile

26[Ref: UK MOD]

Swansea University’s Antenna and Smart City Lab- Amongst the UK best

27

Conclusion

• Modern electronic warfare would need autonomous (real time) adaptive wideband multifunctional antennas systems for

– Concreate jamming avoidance, multipath mitigation, longer ranges, lower cost for sensor network, autonomous distributed systems, longer battery, etc.

• Hence, great importance in defence and security applications

• Expect devices & systems out by 2020

28

29

Title ofpresentation

• Click to edit subtitle style

Title ofpresentationClick to edit subtitle style

THANK YOU !!

29

Contact

a.mehta@swansea.ac.uk