100.000.000419170%$3

Mohammad Khojah

Under the direction of Dr. Atif Shamim

Saudi Research Science Institute

July 24, 2012

An Inkjet Printed Antenna on Leather for Mine Detection in

Battlefields

2

Overview

Overview

Introduction

• Mines

• Problem

• Objective

• Detection

• Inkjet printing

Design process

•Specifications

•Leather

•Simulating

•Printing

•Testing

Conclusion

•Results

•Conclusion

•Future work

•Improvements

•Applications

9/20/2015 3

Introduction

Problem

9/20/2015 4

Bulky

Expensive

Not user friendly

Source Nation/ Defence Days, Esplanade des Invalides, Paris, France, September 24-25, 2005

Mine Detector

9/20/2015 5Introduction

Objective

Fabricate an inkjet printed antenna

for mine detection

that will be embedded in a shoe.

9/20/2015 5

Introduction

Mine Detection

The Project Common Mine Detectors

Antennas Coils

Electromagnetic waves Magnetic fields

Reflection Change in magnetic field

9/20/2015 6

Introduction

Novel Aspects

• Novel printing surface

• Hot air station sintering

• Inkjet mine detector

9/20/2015 7

Introduction

Challenges

The mine detector has to be:

• Cheap

• Flexible

• Small

• Efficient

• Reliable

9/20/2015 8

Introduction

Inkjet Printing

9/20/2015 9

Design Process

Design Process and Evaluation

Antenna Specifications

Comparing Leather

Simulating the Antenna

Printing the Antenna

9/20/2015 10

Design Process

Antenna Specification

Frequency 2.4 GHZ

Wavelength 12.5 cm

Gain 2 dB

Impedance 70+j30

Type Dipole

Range > 5 m

9/20/2015 11

Design Process

Comparing the Leather

Type of Leather Thickness Permittivity Loss Tangent

Black Leather I (Car Seat) 0.5 mm 1.8 C/m2 0.01 δ

Black Leather II ( Clothing) 0.5 mm 2 C/m2 0.01 δ

Brown Leather I (Car Seat) 1.0 mm 1.2 C/m2 0.018 δ

Brown Leather II (Car Seat) 0.56 mm 1.8 C/m2 0.027 δ

9/20/2015 12

Design Process

Antenna Design

9/20/2015 13

Design Process

Gain of the Simulated Antenna

9/20/2015 14

𝑃𝑟

𝑃𝑡= 𝜎

𝐺2

4𝜋

𝜆

4𝜋𝑅2

2

R = 5.98 m

9/20/2015 15Design Process

Range of the Simulated Antenna

9/20/2015 15

Design Process

Impedance of the Simulated Antenna

9/20/2015 16

Reactance = 42

Frqfreq, GHZ

Imp

ed

ance

Ω

Resistance = 67

Determining the Layer Count

• 1 cm x 1 mm

• Four nozzles

• Sintering at 350°C

Design Process9/20/2015 17

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

0 5 10 15 20 25

Layers

Res

ista

nce

ΩΩ

Design Process

Printing

First Antenna Second Antenna

10 layers 10 layers

Oven sintering Hot air station

160°C 350°C

3 hours 3 minutes

9/20/2015 18

Antenna Testing

• Measuring resistance

• Measuring impedance

• Measuring return loss

9/20/2015 19Results9/20/2015 19

Heigh

t o 1

.22

1

Width of 1,628 mm

Results

Impedance

9/20/2015 20

Results

Return Loss

9/20/2015 21

retu

rn lo

ss, d

Bm

freq, GHZ

Efficiency Determination

−25 𝑑𝑏𝑚 = 𝑙𝑜𝑔20𝑉𝑟𝑒𝑓

𝑉𝑖𝑛𝑐

𝑉𝑟𝑒𝑓

𝑉𝑖𝑛𝑐= 0.56 = 5.6%

• 94.4% of the signal power will enter the antenna

• Due to the resistance of the ink, some of the signal power will be dissipated.

9/20/2015 22Results9/20/2015 22

Conclusions

• The printing process is inconsistent

• Leather is a decent substrate

• Our antenna closely meets the specifications

• Matching impedance was achieved

9/20/2015 23Conclusions 9/20/2015 23

Conclusions

Possible Applications

• Shoes that guide blind people

• Part of a radar system

• Electronics printed on clothes

• Treasure hunting

• Any situation where a device needs to sense nearby objects

9/20/2015 24

Parameters to Explore

• Printer

• Ink

• Substrate

• Sintering

9/20/2015 25Conclusions9/20/2015 25

Next Steps

• Choosing a transceiver

• Connecting the antenna

to the transceiver

• Testing the system

• Building the final prototype

9/20/2015 26Conclusions 9/20/2015 26

Acknowledgments

9/20/2015 27Acknowledgments 9/20/2015 27

• Dr. Atif Shamim

• Fahad Farooqui

• Dr. John Dell

• Tutors

• Benjamin Lei

• SRSI

• CEE

• KAUST

• SRSI students

• My family

Q/A