Design and Performance Analysis of the Rectangular Spiral Microstrip Antenna and Its Array Configuration
3 4 2 Md. Tanvir Ishtaique-ul Huque , Md. Shihabul Islam , Mst. Fateha Samad , and Md. Kamal Hosain 1
Department of Electronics and Telecommunication Engineering Rajshahi University ofEngineering and Technology, Rajshahi-6204, Bangladesh 2 1
[email protected] ,
[email protected] , 4 3
[email protected] ,kamal14
[email protected]
Abstract: In this paper a rectangular spiral microstrip antenna are analyzed in term of return loss response and radiation pattern.
1.588 mm Generally the overall dimension of the antenna is 47.3 x 11.9 x 1.602 mm Here, SONNET version V12.56 package is used to obtain the return loss, the gain and the radiation patterns. =
and its array configuration are designed and their performances Microstrip antenna design equations are introduced
and the proposed antenna is simulated by using SONNET
version V12.56 simulator. The resonant frequency of array
.
.
antenna is 10.6 GHz. The main feature of this spiral antenna is
that it can be designed for the operating frequency at any range with higher radiation efficiency compared to other conventional microstrip
antennas
and
its
array
network
configuration
provides higher radiation performance in term of directive gain
11.9
and maximum radiation.
I.
INTRODUCTION
With the rapid growth of the wireless communication technology, the future technologies need a very small antenna which results microstrip antenna. The advantage of microstrip antenna makes them popular in many applications requiring a low profile antenna and this antenna is promising to be a good candidate for the future technology due to the flexibility of the structure as it can be easily incorporated into the communication equipments [1]. Many researchers have studied different structure [7], [8] and different techniques to increase the radiation efficiency in single element antenna by using double PIFA [1], U-slot [2] and other structures. In this paper, an investigation on the design of rectangular spiral microstrip array antenna to achieve higher directive gain and radiation efficiency by matching the impedance of successive elements using the quarter wavelength transformer method [3], is made. This paper aims to reduce the size of the antenna and at the same time to improve the radiation performance of the patch antenna in terms of gain, maximum radiation. As an advantage of this antenna, resonant frequency can be easily controlled by either increasing or decreasing some parameters such as, width and length of each element. Here, the designed microstrip antenna supports 10.6 GHz and it can also be designed for any number of operating frequency at any range by supporting array configuration. II. ANTENNA CONFIGURATIONS AND DESIGN PROCEDURE This antenna has a simple structure fed by 50n microstrip line. Fig. 1 and Fig. 2 demonstrate the dimensions of the proposed single element and three elements array configuration of the spiral antenna respectively, used for theoretical and simulated study where the dimensions are in mm range. The dielectric material selected for the design is Taconic TLY-5 which has dielectric constant of 2.2 and height of dielectric substrate (h) 978-1-4244-6908-6/10/$26.00 ©2010 IEEE
219
Fig. I Detailed dimensions of the proposed single element rectangular spiral microstrip antenna
=
Fig. 2 Detailed dimensions of the proposed rectangular spiral microstrip array antenna
For an efficient radiation a practical width of the patch is [3] W=
2f'fo:s.x�/+1
(1)
And the length of the antenna is L=
5
1
2f,.�&eff�&0J10
-2M
M
(2)
·5
·10
Where,
+0.264 0.3 + h & e ff * """"-.--....,.-'.,,M,=0.41h 0.258 &eff ; +0.8
(w (
-15
)
(dB)
(3)
)
8.5 8 Sonnet Software Inc.
&r+l + &r-l &eff=2- � 2V 1+12 ;
t 9
Frequency (GHz) 9.5
10
10.5
11
Fig. 3 Return loss response of the single element spiral microstrip antenna
(4)
The radiation pattern of this antenna of Fig. 1 for the operating frequency of 10.8 GHz is shown in Fig. 4 by using the same simulator and the directive gain is found 7.57 dB at 10.8 GHz and HPBW becomes 105°. Similarly in case of using the single element rectangular microstrip antenna the measured HPBW is approximately in the range 150°-170° as well as the less directive gain is achieved. So the single element spiral patch antenna results higher directive gain and radiation efficiency of than that of the single element patch antenna [6].
TABLE 1 CONFIGURATION FOR SINGLE ELEMENT AND THREE ELEMENTS SPIRAL ARRAY
Antenna Type
Antenna
-20
�
-25
And
Single Element
Three Elements
Antenna (mm)
Array (mm)
Length, L
9.1
47.3
Width, W
9.1
11.9
Dimension
0
9
fr is the resonance frequency, L and Ware the length and width of the patch element and &r Where, A is the wave length,
is the dielectric constant. Here, the antenna seems to be a series feed array network [5]. In Fig. 2, the antenna has designed to cover specific operating frequency (10.6 GHz) whereas because of their array network configuration the antenna provides efficient radiation performance in term of gain and directivity compared to the conventional rectangular microstrip array antenna. In this array network configuration each element consists of four equal widths (1 mm) turn whereas two successive turns are separated by 0.1 mm gap. Here two successive patch elements are matched by using quarter wavelength transformer method [5]. III. ANTENNA SIMULATION AND RESULTS The return loss response of the proposed single element microstrip antenna simulated at the SONNET version V12.56 is shown in Fig. 3, where the maximum return loss i.e.23.1378dB is found at 10.8 GHz operating frequency and the bandwidth is close to 10.5-10.9 GHz whereas the conventional rectangular single element microstrip antenna has the maximum return loss up to -19 dB [6].
220
Fig. 4 Radiation pattern at 10.8 GHz of the single element spiral microstrip antenna
Again, the proposed spiral microstrip array antenna of Fig. 2 is simulated at the SONNET version V12.56 and the return loss response is shown in Fig. 5 and the maximum return loss i.e.-II.74 dB is found at 10.6 GHz operating frequency and the bandwidth is close to 10.5 - 11 GHz, on the contrary the conventional three elements rectangular microstrip array antenna is found with the maximum return loss up to -7 dB [6].
TABLE 2 COMPARISON OF THE RESULT OF DESIGNED SPIRAL ANTENNA AND CONVENTIONAL ONE
2
M
0
Antenna Type
-2
-4
Performance
+
Three
Element
Elements
Spiral
Array
Less than 7
7.57
Less than 8
9.3 5
150°-170°
105°
90°-145°
3 5°
Parameter
Element
-6
t
-8
(dB)
-10
Directive gain(dB)
+
HPBW
-12 8
9
8.5
Sonnet Software Inc.
9.5
10
Frequency (GHz)
10.5
Three
Single
Single
Elements Spiral Array
11
Fig. 5 Return loss response of the three element spiral rnicrostrip array antenna
The radiation pattern of this antenna of Fig. 2 for the operating frequency of 10.6 GHz and 8GHz is shown in Fig. 6 by using the same simulator and the directive gain is found 9.35 dB at 10.6 GHz and HPBW becomes 35°. In contrast the three element microstrip array antenna the measured HPBW is approximately in the range 90°-145° as well as the less directive gain is achieved which shows that the three element spiral microstrip array antenna provides better performance than that of the three element microstrip array antenna[6].
V. CONCLUSION The unique feature of this antenna is its simplicity to get higher performance. This paper presents a geometric configuration for the microstrip, which provides a mean to get higher directive gain and maximum radiation efficiency without using special techniques. Its array configuration provides a mean to get higher directivity in a compact structure than simple microstrip array. Here the series fed array configuration has investigated and in future the corporate-series fed array configuration can be designed and simulated operating more than one operating frequencies and having higher directive gain by using the single antenna. REFERENCES [1].
Gain (dB)
P. S. Hall,E.Lee,C. T. P. Song,Planar Inverted-F Antennas Chapter7,"Printed Antennas for wireless Communications" Edited
by R. Waterhouse,John Wiley & Sons,Ltd.,2007.
Frequency (GHz) 80 . GHZ
_
10.6GHZ
_
[2].
H. F. AbuTarboush,H. S. AI-Raweshidy, R. Nilavalan,"Triple Band Double V-Slots Patch Antenna for WiMAX Mobile Applications", 14th Asia-Pacific Conference on Communications,
Japan,pp. 1-3,2008. [3].
Phi 00 . Degrees
C. A. Balanis, "Antenna Theory", 2nd Edition, John Wiley &
Sons,Inc.,1997.
0
[4].
R. A. Bhatti, Young Sin Shin, Ngoc-Anh Nguyen and eong-Ook Park,"Design of a Novel Multiband Planar Inverted-F Antenna for Mobile Terminals," Antenna Technology: Small Antennas and
E Field E Total
Novel Metamaterials, 2008. IWAT 2008.1nternational Workshop on,pp. 530-533,2008. [5]. -135
Garg, R., P. Bhartia, I. Balli, and A. Ittipiboon "Microstrip Antenna Design Handboo!C', Artech House,Inc.,2001.
135
[6].
Md. Shihabul Islam and Md. Tanvir Ishtaique-ul Huque, "Design, Simulation
and
Performance
Analysis
of
Microstrip
Array
Antenna ", B.Sc. Engg. thesis, Dept. of ETE, Rajshalli University
of Engineering &
Fig. 6 Radiation pattern at 10.6 GHz and 8 GHz of the three element spiral microstrip array antenna.
Technology(RUET), Rajshalli, Bangladesh,
April 2010 [7].
IV. RESULT COMPARISON For the convenience the result of simulated spiral microstrip antennas and conventional antennas are summarized. From the result shown in TABLE 2 it can be concluded that the designed antenna out perform the conventional one.
Dinisio Raony Ribeiro, Leonardo Augusto de Santana, Marlen Carneiro Alves and Jose Felipe Almeida, Carlos Leonidas da S.S. Sobrinho, "Spiral Microstrip Antenna", IEEE MTT-S International
Microwave & Optoelectronics Conference (IMOC 2007), pp. 104-
106,2007. [8].
A.
Mehta, D.
ELEMENT
Mirshekar-Syallkal, and H.Nakano,
BEAM
STEERABLE
ANTENNAS
"SINGLE -
FROM
RECTNAGVLAR SPIRAL TO STAR", EMTS 2007 International
URSI Commission B-Electromagnetic Ottawa,ON,Canada,July 26-28,2007.
221
Theory
Symposium,
