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Gigabit Wireless Communications at 60 GHz. T. Rama Rao and S.Ramesh. RADMIC, Dept. of Telecommunication Engineering, SRM University, Kattankulathur ...
IEEE-20180

Microstrip , Slotted Rectangular Waveguide Array and Patch-fed Rod Antenna Design and Simulation for Gigabit Wireless Communications at 60 GHz T. Rama Rao and S.Ramesh RADMIC, Dept. of Telecommunication Engineering, SRM University, Kattankulathur - 603203, TN. [email protected], [email protected]

Abstract-This paper deals with the design of 2x2 Microstrip,

proliferate across very wide variety of consumer devices over the

Slotted rectangular waveguide antenna array and Patch-fed rod

next years. Within these Mm wave radio technologies, various kinds

antennas

of wireless data transmissions and advanced information services are

wireless

needed

for

ultra

communication

high-speed,

systems

which

ultra

high-capacity

work at

Millimeter

waves at 60 GHz for different multimedia applications in indoor environments and illustrates its specifications and requirements. The antenna in such systems requires high gain, high-efficient, wider beamwidth and high performance design specifications. The designed antennas were simulated using electromagnetic software Agilent's EMPro and Ansys HFSS. Keywords-Millimeter

Waves,

60

2x2

GHz,

expected to develop with/without license. Strong attenuation over the free space due to the smaller wavelengths, oxygen absorption and severe attenuation by walls allow frequency reuse and user privacy [4, 5, 6] makes Mm waves based wireless technologies an attractive proposition for ultra-high-speed new generation WLANIWPAN's [7]. Therefore, our present work targets on addressing challenges in

Microstrip

and

Slotted rectangular waveguide Antenna Array, Patch-fed rod antenna, Design and Simulation.

designing Microstrip, Slotted rectangular waveguide antenna array Patch-fed rod antenna for the realization of Mm wave based wireless communication networks

[8],

particularly at 60 GHz utilizing

Agilent's EMPro and Ansys HFSS simulations. The paper is I.

In

today's

organized as follows; Section 2 deals with technical challenges,

INTRODUCTION

technological

digital

society,

wireless

communication technologies has become an increasingly important part of daily life and emerged leading to significant

especially on Antennas design and development. Section 3 deals with results obtained in our present work and discussions. Finally, Section 4 gives conclusions.

changes in lifestyles. From cellular mobile phones to satellite whether they transmit or receive is the antenna [1]. The ever­ increasing need for mobile/wireless communications and the emergence

of

new generation

technologies required

TECHNICAL CHALLENGES

II.

dishes, the common element in all these wireless systems Antennas

are

the

most

critical

& ISSUES

component

ill

wireless

communication systems, and can be regarded as a means for

an

radiating or receiving Mm waves. Antennas with excellent design

efficient design of antennas of smaller size for wide range of

can improve the communication performance. Due to the short

variety of applications with style and performance Variety

of

wireless

applications

such

as

online

[2].

wavelengths of the Mm waves, it is easy to obtain an electrically

video

larger antenna aperture. It means that high gain and angular

streaming, online games, digital video streaming, medical

resolution are easily obtained. However, it is also difficult to develop

data collection and health care applications etc, desires some

an

special requirements, such as high data rate, larger capacity,

requirement and large metal and dielectric loss.

Mm-wave

antenna

because

of

the

rigorous

manufacturing

limited communication area, and high angular resolution [3]. Despite many advantages offered and high potentials applications Recently, emerging systems of Gigabit (GiFi) wireless

envisaged in 60GHz, there are number of technical challenges and

higher

open issues that must be solved prior to the successful deployment of

frequencies at 60 GHz with capabilities of GiFi data rates.

this technology. These challenges can be broadly classified into

Corresponding to these ultra-high data rates, the bandwidth of

channel propagation, antenna technology, RF section, and choice of

communications

are

pushed

into

regimes

of

operation are also stretched to millimeter (Mm) waves at 60

modulation. Many types of antenna structures are considered not

GHz. The radio systems at Mm wave frequencies including

suitable

its antennas are required to enable these wide bandwidth

requirements for low cost, small size, light weight, and high gain. In

for

60GHz

WPAN/WLAN

applications

due

to

the

transmissions for high-speed broadband wireless local area

addition,

networks (WLAN) and wireless personal area networks

approximately constant gain and high efficiency over the broad

(WPAN) communication systems which are expected to

frequency range (57-66 GHz) [8, 9].

60 GHz antennas also require to be operated with

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lEEE-20180

From the configuration standpoint, most antenna forms in

L

Mm waves are similar to those in microwaves. However, some forms are more suitable and popular in Mm-wave

=

{I I {2f, �JIO�O J�reff }} -

2 LlL

(4)

Using electromagnetic software Agilent's EMPro the simulation

applications, such as microstrip, slot and rod antenna. The

is carried out, with the spacing defining for x= 3.5

choice of antennas for Mm wave depends on the applications

mm between the antennas a maximum gain of 13 dBi is achieved.

rum

and y =3.2

and the propagation environment, but clearly both a broad­

Study on

beam antenna and directional antennas are required. The

A maximum gain for al = 0.2

microstrip antenna, slot antennas are belongs to broad beam

optimization [14, 15]. The size of the patch array for the optimized

category and rod antenna is directional.

array gain due to the effect of feed network is perceived.

spacing is 5.35

rum

rum

and bl=0.45

rum

is seen after

by 4.65 mm is shown in the Fig. l.

Recently, the technology of planar integrated antenna has been developed for Mm wave applications due to the trend of the integration in radio frequency front-end circuits and

rnm __



systems. As the operating frequency of wireless systems move into Mm wave range in order to provide gigabytes per second service, there is an increasing demand of high gain

.65

antennas used for consumer devices. The desired antenna has to be compatible with integrated circuits, and possess high gain and small side lobe. The antenna, when integrated into consumer devices, should also have the benefits of small size and low production cost [10, 11]. However, wider beamwidth, high directional antennas either require large size such as Microstrip or Slotted rectangular waveguide array or Patch­ fed rod antennas.

Fig.

I. Top view of2x2 Microstrip array antenna with dimensions

Slotted rectangular waveguide antenna array is a very low loss III.

transmission line. Energy contained inside a waveguide can be

ANTENNAS DESIGN

The 2x2 Microstrip array antenna is a planar structured with high gain and efficient radiation which can be integrated conveniently with the rest of the system. A typical single rectangular patch antenna can provide 7 dBi gain and greater than 30° beamwidth when its fundamental mode (TMIO) is excited. The procedure assumes that the specified information includes the dielectric constant of the substrate resonant frequency

(£-),

( c,) ,

the

and the height of the substrate (h).The

design proceeded with the help of the theory and below equations [12, 13]. For an efficient radiator, a practical width

radiated and transmitted by arrays of slots which act as antenna elements along the waveguide. Slots are ideal antenna elements that can easily be incorporated into the waveguide walls without the need for special matching networks that other types of antennas often require. Waveguides have a defined waveguide wavelength

(Ag),

which is related to the frequency of operation inside a waveguide, and which is different from free-space wavelength. A waveguide has a cut-off frequency (fc) below its operating frequency. The cut-off wavelength

(Ac)

and waveguide wavelength

(Ag)

are related to each

other as shown in the equations [16],

(W) that leads to good radiation efficiency is calculated using,

W=1I(2f,�tto�o){.J2/(';r+l)}=

Vo/2f,

{.J2/(';r+1)}

(5)

(1)

where Yo is the free-space velocity of light. The effective

(6)

dielectric constant of the Microstrip antenna calculated using,



iff ={(�r +1)/2+(�r -1)/2}{1+(l2hlw)}-

(I/Z)

(2)

re

Once W is found then using above equation values to determine the extension of the length

LlL using,

&/h=0.412{(;reff+O.3) W/h+0.264}/{(;reff-0.258) W/h+O.8} The length using

(L)

(3)

of the patch can now be determined by

where subscripts m and n represent the number of

YzAO

variations

along the large 'a' and small 'b' inside dimensions respectively. Slots need to be narrow and approximately

YzAO

long to ensure that

the distribution of the electric and magnetic fields along them is sinusoidal. The slot length can be extended or reduced by

Yz5Ao

without interfering with the frequency of operation. The slots need to be narrow and their width small compared to their length. The ratio of slot width to its sloth length should be 1 :9. The Spacing between the slots should be approximately equal to

YzAg.

If this spacing is

changed it causes a shift in the operating frequency. This distance

ICCCNT'12 h tll 26t _2S July 2012, Coimbatore, India

IEEE-20180

between slot centers needs to be accurate to ensure that the antenna operates properly at operating frequency [20].

design the patch-fed rod antenna. A rod antenna is designed with a patch. The rod consists of a cylindrical and tapered part. The rod is fed by a patch which is sequentially energized by a microstrip line connected to a coaxial connector. The antenna configuration can be

-i" .t

Slot: t:OTo- _-_- _-_-

easily built and integrated with other millimeter-wave functional modules or planar circuits [19, 20]. A patch-fed patch antenna of 1.98 mm by 0.56 mm has been designed at 60GHz. The patch

SIOot:

-30 -

I

--

V

'" ./

...... :\

r

-40

THETA

Fig. 4(a). 2D radiation pattern of the 2x2 Microstrip array antenna

Fig. 3. Patch-fed rod antenna

A dielectric rod in the patch-fed rod antenna can act as a guide for electromagnetic waves. Considerable millimeter­ wave power propagates through the surface of the rod and is radiated to free space. This radiation tendency is used to

Fig. 4(b). 3D radiation pattern of the2x2 Microstrip array antenna symmetric around the normal axis

ICCCNT'12 h d 26t _28 l July 2012, Coimbatore, India

IEEE-20180

The

Slotted

rectangular

waveguide

antenna

array

simulation carried out using Agilent's EMPro. With the antenna dimensions a= 3 rum and b =1.5 rum and 0.01 rum wall thickness, a maximum gain of 14.59 dBi is achieved. The operating frequency of the antenna was used to determine all physical dimensions of the waveguide and the radiating slots. The simulated results were used as guidelines for the various slot parameters. The slot length was kept at �A.o (0.24mm) according to the waveguide theory, while the slot width was calculated to be 0.02rum using the 1:9 width-to­ length ratio that was identified using the simulated results. The spacing between the slots is 0.045rum. The parameters

Fig. 5(b).

VSWR for the slotted rectangular waveguide array antenna

and dimensions are shown in the Table. I for a rectangular waveguide slot array antenna with 8 slots.

TABLE I. PARAMETERS OF WAVEGUIDE SLOT ARRAY DESIGN

Parameters

Values

Slot position from port

162 mm

Waveguide wall thickness

3 mm

Slot to top

40.5 mm

Recta�ular waveguide short side

44 mm

Slot length

58. 3 mm

Slot width

6.5 mm

Number of slots on each side

8

Slot spacing

81 mm

Slot offset

9.2 mm

Rectangular waveguide wide side

94 mm

Fig. 5(c). 3D Radiation pattern for the slotted rectangular waveguide array antenna

The patch-rod antenna has been simulated and analyzed using

The slot array antenna is designed with 8 numbers of slots by using a substrate copper with specifications 5.8x107 S/m

Ansys HFSS V14.0. Rather the results have been observed. The

conductivity and with relative permittivity of 1. Simulations

choice of design parameters mainly the rod height and the position of

had also shown that, as the number of slots increases gain increases by 3dBi. The simulation of an 8-slots design shows a stable 14.59 dBi gain, VSWR 2.43 and beamwidth 22.6° at 60 GHz is achieved. The Gain, VSWR and 3D radiation pattern of the slotted rectangular waveguide antenna array is shown in the Fig. 5(a), 5(b) and 5(c) respectively. , ..

1 .. .. ..

, ....

1' ..... '.

, ..

1 ..... "

...........-. __ .......... -...... -....... � .... �--

rod with respect to patch.

The radiation pattern and 2D gain total

results for patch-fed rod antenna are given in Fig. 6(a) and 6(b) respectively. The Patch-fed rod antenna is more efficient with gain and beam width when compared to probe fed patch antenna [21]. The compromise between high gain and small side lobe is obtained by the proper choice of design parameters mainly the rod height and the position of rod with respect to patch.

........- ........ ___ ...-. ....... --.-.--..

....... _.

compromise between gain and side lobe is obtained by the proper

AnsotLLC

Radiation Pattern 3 OJlVe�fo

........... .. ...- , ...

, ......

.. " ...

, .... ..

-dB(GailTClaI)

.....W!.

1

Serupl:LsstAdaplilte

�....-, .......

.... ...-.-... _____ ............. _ .......__ a.

"WI'

1 .... .

Freq='6OGH!:'RlP'Odeg'

1'-"

d8(GailT«aI) 5«Iipl:lastAdaplilte Freq='6OGH!:'AlP'9CkJeg

90

-180 lIII

Fig. 5(a). Gain for the slotted rectangular waveguide array antenna

Fig. 6(a). Radiation pattern of patch-fed rod antenna

ICCCNT'12 h d 26t _28 l July 2012, Coimbatore, India

IEEE-20180 Ansoft LLC 15.oo

XY Plot 5

..�

_t�����

Pa1ch_Antenna_ACKv1

--t-------.:..:....:. .: � ..:.:: -1:---

T

"' "· �,

-dB(GainTctaO Setupl:LastAdap\i.te

1 0.00

Freq:'600It'AlF():jeg'

5.00

-

-dB(GainTctaO Setupl:LastAdap\i.te Req:'600It'AlF9)jeg'

+-

[3]

S.K.Yong, "Multi giga bit wireless through millimeter wave in 60GHzband", in Proceedings of Wireless Conference Asia, Singapore, November 2005.

[4]

Teshirogi and T. Yoneyama, Eds. "Modern Millimeter-Wave Technologies", Ohmsha Ltd., Tokyo, Japan, 200I.

[5]

Hans Schantz," The Art and Science of Ultra wideband Antennas", Artech House, Norwood, MA, USA, 2005.

0.00

+-+

-

[6]

"Next-Generation Broadband Wireless Access Technologies," NTT Technical Review, Vol. 2, No. I, pp. 12-63, 2004.

[7]

T. Ihara and K. Fujimura, "Research and development of millimeterwave short­ range application systems," Trans., IEICE, Vol. E79-B, No. 12, pp. 1741-1753,

-15.00

Dec. 1996. [8]

-2 0.00

"60 GHz technology & Sons

for Gbps WLAN and WPAN: From TheolY to Practice", John Wiley Ltd., 201 I.

-25.00 - 0 3 ·

Su-Khiong Yong, Pengfei Xia and Alberto Valdes Garcia,

� 2-:i00�.00-� .15'0.00--.,"T00.� . CC .00�� 0'.00 --5"'0.00- 00"'. 00�00 - �� 50 00.00 ' 5TO. 00- -2 -:1 1� Theta [deg[

[9]

FCC" First Report and Order", February 2001, http://hraun-foss.fcc.gov/edocs public

[10] Shao-Qiu Xiao, Ming-Tuo Zhou Yan Zhang, "Millimeter Wave Technology for

Fig. 6(b). 20 gain Total of patch-fed rod antenna

Wireless LAN, PAN and

MAN", Auerbach Publications, 2008.

[II] C. A Balanis," Antenna Theory Analysis and Design", John Wiley, New York, USA, 1997. V.

CONCLUSIONS

[12] C. Kamfelt, P. Hallbjorner, H. Zirath, and A Alping, "High gain active microstrip

Broadband Mm-wave transmission in the 60 GHz range enables WLAN/WPAN systems with regard to increasing data rates. The use of mm-wave techniques offers many

[14]

The

Agilent's EMPro

designed

and Ansys

antennas HFSS

simulated

software.

IEEE

Millimeter-Wave Wireless

Applications",

in

Xihui Tang, H. Wong, Yunliang Long, Quan Xue, and K. L. Lau, "Circularly Shorted

Patch

Antenna

on

High

Permittivity

Substrate

LTCC with embedded-cavity substrates", IEEE Trans. Antennas

& Propagation,

vol. 56, no. 9,pp. 2865-2874, Sep. 2008. [16]

A Rosen, R. Arnantea, P. Stabile, A Fathy, D. Gilbert, D. Bechtle, W. Janton, F. McGinty, J. Butler, and G. Evans, "Investigation of active antenna arrays at 60 GHz", IEEE Trans. Microw. Theory. Tech., vo1. 43, no. 9, pp.2117-2125, Sep. 1995.

[17] Roland A Gilbert, "Waveguide slot antenna arrays" McGraw Hill, 2007.

width of 40°, Slotted rectangular waveguide array antenna has

[18]

The reasonable agreement with the simulated results verifies the designed antennas can be used for different multimedia applications in indoor environments at Mm-wave frequency 60 GHz.

with

& Propagation, VOL. 60, NO. 3,

Microstrip array antenna has a gain of 13 dBi and a beam

rod antenna has a gain of 10.8 dBi and a beam width of 40.4°.

IEEE

pp.1588-1592,March 2012.

2x2

a gain of 14.59 dBi and a beam width of 22.6° and Patch-fed

Trans.

[15] A Lamminen, J. Saily, and A Vimpari, "60 GHz patch antennas and arrays on

using

The

Emerging

Wideband" in IEEE Transactions on Antennas

communications require high gain, high efficiency and more environments.

for

Polarized

the requirements and specifications of different antennas

beam width specifically for multimedia applications in indoor

WLAN/WPANapplications,"

Transactions on Ant. and Prop. Vol. 59, NO. 5, pp.1742-1747, May 201 L

state-of-the-art design flow is required. This work investigates

at Mm-waves at 60 GHz. The antennas for GiFi wireless

60-GHz

Nezhad-Ahmadi, and Safieddin Safavi-Naeini, "Optimized Microstrip Antenna Arrays

radio techniques at lower frequencies. But for commercial

needed for GiFi wireless communication systems which work

for

[13] Behzad Biglarbegian, Mohammad Fakharzadeh, Dan Busuioc, Mohammad-Reza

advantages for short-range wireless systems compared to applications, a cost effective process technology along with a

antenna

Microw. Theory Tech., vol. 54, no. 6, pp. 2593-2603, Jun. 2006.

A Bakhtafrooz and A Borji, "Novel Two-Layer Millimeter-Wave Slot array antennas

based

on

substrate

integrated

waveguides",

in

Progress

In

Electromagnetics Research, Vol. 109, 475-491, 2010. [19] Y. Shiau, "Dielectric rod antenna for millimeter wave integrated circuits," IEEE Tran. Microwave Theory Tech., vol. 24, no. 11, pp. 869-872, Nov. 1976. [20] S. Kobayashi, R. Mittra, and R. Lampe, "Dielectric tapered rod antenna for millimeter wave applications," IEEE Trans. Antennas

& Propagation, voL30, no.

1, pp. 54-58, Jan. 1982. [21] Kao-Cheng Huang and Zhaocheng Wang , "V-band Patch-fed rod antennas for high data-rate wireless communications", in IEEE Ttransactions on Antennas and Propagation, vol. 54, no. 1, pp.297-300, January 2006.

ACKNOWLEDGMENT

Authors are very much grateful to DRDO, Govt. of India for their financial backing to carry out this research work.

REFERENCES [1]

P. Geddes, "The Life and Work of Sir Jagadish Longmans, Green

[2]

& Co., 1920.

C. Bose", New York,

AD. Oliver, "Millimeter wave systems-past, present and future", lEE Proceedings, vo1.l36, no. I, pp. 35-52, 1989.

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