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Car Antennas

Luis Brás, Nuno Carvalho,

Pedro Pinho

Instituto de Telecomunicações - Aveiro, Portugal

bras@ua.pt

2

Outline

• Introduction

• Car antennas

• Transparent Conductors

• Transparent Antennas

• Conclusions

3

Services of today

• GSM/UMTS

• Elect. Toll Collec. (ETC)

• Satelitte Radio

• DVB-S

• Tire Pressure... (TPMS)

• Remote Key Entry (RKE)

• ...

4

AM-Radio

0.5 – 1.7 MHz

FM-Radio

78 – 108 MHz

RKE/TPMS

315 – 433 MHz

TV

470 – 880 MHz

GSM

824 - 960 MHz

L1/L2-GPS

1227/1575 MHz

GSM

1710 - 1990 MHz

WiFi/Bluetooth

2400 - 2500 MHz

Satellite TV

12200 - 12700 MHz

Radar Collision

Detection System

22000 – 26000 MHz

76000 – 77000 MHz

ETC

5800 MHz

V2V V2I

5900 MHz

Frequency (MHz)

Frequency Spectrum

5

Car Antenna requirements

• System requirements (RP, BW, polarization)

• Vehicular requirements

• Aesthetics

• Manufacturability

• Weather resistance

• Weight/Cost

• Vandalism

• Damage resistance

(car wash, tree branches,...)

6

Outline

• Introduction

• Car antennas

• Transparent Conductors

• Transparent Antennas

• Conclusions

7

1

Car Antennas (1)

AM/FM (helical antenna)

GPS/cellular design

(Patch/IFA/Slot Antenna) 5

6 2 3 4

7

8

8

Car Antennas (2)

Satellite TV Antenna

(Phased Array)

1

5

6 2 3 4

7

8

9

Car Antennas (3)

AM/FM

DAB

Traffic Msg. Control (TMC)

(Mendered Microstrip)

1

5

6 2 3 4

7

8

10

Car Antennas (4)

ETC (BendMonopole/IFA)

Cellular (Dual Band Microstrip)

GPS (CP Patch)

1

5

6 2 3 4

7

8

11

Car Antennas (5)

1

5

6 2 3 4

7

8

AM/FM

DAB

TV

GPS

(Mendered Microstrip)

12

Car Antennas (6)

Automotive Radar Antenna

(Microstrip Antenna Array)

1

5

6 2 3 4

7

8

13

Car Antennas (7)

Tire Pressure Monitoring

Systems (TPMS)

(Microstrip mendered)

1

5

6 2 3 4

7

8

14

Car Antennas (8)

Remote Start engine (RSE)

Remote Keyless entry (RKE)

(loop, bend & mendered

Monopole)

1

5

6 2 3 4

7

8

15

Omnidirectional Microstrip Array

-30

-30

-20

-20

-10

-10

0 dB

0 dB

90o

60o

30o

0o

-30o

-60o

-90o

-120o

-150o

180o

150o

120o

Measured

Simulated

Implemented Antenna for DSRC

16

We defined new requirements

Transparent Antenna

Beamforming Networks

Array • Higher Gain

• Beam Control

• Reduced Impact

to the driver view

System integration

Directive transparent Antennas

Beamforming network

17

Outline

• Introduction

• Car antennas

• Transparent Conductors

• Transparent Antennas

• Conclusions

18

Transparent Conductors

Transparent

Conductor

Characteristic

Indium Tin

Oxide (ITO)

Most commonly used, durable, chemical resistance

to moisture, can be precisely etched

Indium Zinc Oxide

(IZO)

Is used quite often in the LCD’s, easily etchable,

but not as durable as ITO

Zinc Oxide with

Aluminum (AZO)

Lower cost and relatively good optical transmission,

lower chemical resistance to moisture

Fluorine doped Tin

Oxide (FTO)

Difficult to etch fine patterns has made its use

primarily for plasma displays

19

Transparent Conductors (common application)

Advantages Low production cost

High resistance to dust and water

Best used with a finger, gloved or stylus

Best suited for handwriting recognition

Disadvantages Not too sensitive

Poor contrast

Does not support multi-touch

Advantages Looks brighter and sharper

Highly touch sensitivity

Supports multi-touch

Disadvantages Not working with simple gloves

More expensive

Glass is more prone to breaking

20

Outline

• Introduction

• Car antennas

• Transparent Conductors

• Transparent Antennas

• Conclusions

21

Transparent Antennas

Conductive films can be used for antennas, however with poor

radio frequency performance...

ALTERNATIVE?

Grid antennas...

22

Grid Antennas (1)

Reference Antenna

Space between metal strips

(100 um, 200 um, 300 um)

23

Grid Antennas (2)

Space between metal strips

(100 um, 200 um, 300 um)

Reference Antenna

24

Conclusions

• Transparent antennas can be a solution for car antennas

• ITO based antennas can be a solution, however with

poor RF performance

• Grid antennas are a valid alternative

• Transparency is inversely proportional to antenna

efficiency

25

Thanks for your attention…