Wireless Technology Lab., Kyung Hee UniversityWireless Technology Lab., Kyung Hee University

S-band Patch Antenna Design for CINEMA

Chungju Kimkimcj@khu.ac.kr

Wireless Technology Lab., Kyung Hee University

Design Goal

- S-Band Patch Antenna

Size 80 X 80 mm

Bandwidth 60 MHz (2.185~2.245 GHz)

Antenna Polariza-

tion

Right Hand Circular Polariza-tion (RHCP)

RHCP Gain Over 5 dBic

Axial Ratio Below 3 dB

Wireless Technology Lab., Kyung Hee University

Antenna Polarization(1)

- What is the Antenna Polarization The polarization of an antenna is the direction of the electric field (E-plane) of

the radio wave with respect to the Earth's surface and is determined by the phys-ical structure of the antenna and by its direction.

Vertical Polarization

Horizontal Polarization

LH Circular Polarization

RH Circular Polarization

Wireless Technology Lab., Kyung Hee University

Antenna Polarization(2)

- Why use the CP antenna for CINEMA? Space communication has forced the use of Circular polarization. The funda-mental advantage of circular polarization is that all reflections change the direc-tion of polarization, precluding the usual addition or subtraction of main and re-flected signals. Therefore there is far less fading and flutter when circular polar-ization is used at each end of the link.

Wireless Technology Lab., Kyung Hee University

Antenna Polarization(3)

Wireless Technology Lab., Kyung Hee University

Rectangular Patch antenna(1)

- Geometryw

a

w

t

t

/ 2w

38.35

7.9

10.175

w mm

t mm

a mm

Wireless Technology Lab., Kyung Hee University

Rectangular Patch antenna(2)

- S-parameter

- Bandwidth(-10 dB)

EM 69 MHz (2.187~2.256 GHz)

Meas. 130 MHz (2.119~2.249 GHz)

Wireless Technology Lab., Kyung Hee University

Rectangular Patch antenna(3)

- Axial Ratio(Meas.)

<xz-plane>

<yz-plane>

xz-plane 24 MHz (2.145~2.169 GHz)

yz-plane 21 MHz (2.155~2.176 GHz)

- Axial Ratio below the 3 dB

Wireless Technology Lab., Kyung Hee University

Rectangular Patch antenna(4)

- Radiation Pattern(Meas.)

<xz-plane>

<yz-plane>

RHCP Gain

6.056 dBic

LHCP Gain

-14.03 dBic

- Max. CP Gain at 2.160 GHz

RHCP Gain

5.94 dBic

LHCP Gain

-12.52 dBic

- Max. CP Gain at 2.160 GHz

Wireless Technology Lab., Kyung Hee University

1w

1w

Double layer Patch antenna(1)

- Geometry

1

2

35

36.05

13

9.025

w mm

w mm

t mm

a mm

t

t

2w

2wa 2 / 2w

<First Layer> <Second Layer>

Wireless Technology Lab., Kyung Hee University

- S-parameter

Double layer Patch antenna(2)

- Bandwidth(-10 dB)

EM 71.2 MHz (2.164~2.236 GHz)

Meas. 123.8 MHz (2.131~2.254 GHz)

Wireless Technology Lab., Kyung Hee University

Double layer Patch antenna(3)

- Axial Ratio(Meas.)

<xz-plane>

<yz-plane>

xz-plane Out of range

yz-plane Out of range

- Axial Ratio below the 3 dB

Wireless Technology Lab., Kyung Hee University

Double layer Patch antenna(4)

<xz-plane>

<yz-plane>

- Radiation Pattern(Meas.)

RHCP Gain

6.447 dBic

LHCP Gain

-1.931 dBic

- Max. CP Gain at 2.205 GHz

RHCP Gain

6.273 dBic

LHCP Gain

-8.186 dBic

- Max. CP Gain at 2.205 GHz

Wireless Technology Lab., Kyung Hee University

Double-fed Patch antenna(1)

- Geometry

<First Layer> <Second Layer>

Wireless Technology Lab., Kyung Hee University

- S-parameter(EM Simulation)

Double-fed Patch antenna(2)

- Bandwidth(-10 dB)

EM 70 MHz (2.19~2.26 GHz)

Wireless Technology Lab., Kyung Hee University

Double-fed Patch antenna(3)

<xz-plane>

<yz-plane>

- Radiation Pattern(EM Simulation)

RHCP Gain

7.49 dBic

LHCP Gain

-13.542 dBic

- Max. CP Gain at 2.2 GHz

RHCP Gain

7.49 dBic

LHCP Gain

-13.542 dBic

- Max. CP Gain at 2.2 GHz

Wireless Technology Lab., Kyung Hee University

SUMMARY

Rectangular Patch

Antenna

Double layer Patch

Antenna

Double-fed Patch

Antenna

EM Meas. EM Meas. EM Meas.

Center Frequency2.211

GHz

2.184

GHz

2.20

GHz

2.192

GHz

2.225

GHz-

Reflection coeffi-

cient bandwidth

69

MHz

130

MHz

71.2

MHz

123.8

MHz70MHz -

Polarization type RHCP RHCP RHCP RHCP RHCP -

Circular Polariza-

tion Gain7.26dBic 6.00dBic 7.45dBic 6.36dBic 7.49dBic -

Minimum Axial

Ratio

(Frequency)

1.52dB

(2.215

GHz)

1.73dB

(2.16

GHz)

0.932dB

(2.215

GHz)

3.34dB

(2.205

GHz)

0.82

(2.2

GHz)

-