Design of Rectangular Patch Antenna Array with Multiple Slots by Using Mitered Bend Feed Network for Multi-Band Applications D. Prabhakar, Assoc.Prof. Dept.of ECE, DVR & Dr. HS MIC College of Technology, India.
[email protected]
Dr. P.Mallikarjuna Rao, Professor
Dr. M.Satyanarayana, Assoc. Prof
Dept.of ECE, AUCE (A), Andhra University, India.
[email protected]
Dept.of ECE, M V G R College of Engineering (A), India.
[email protected]
Abstract: The design of four element microstrip patch antenna array with rectangular slots is presented in this paper. This is simulated and analysed in detail by using Mitered bend feed network which is used in wireless application in ISM frequency bands. HFSS 13.0 is used to accomplish this work; besides, its fabrication is done by using photolithography technique, devised by “FR4-epoxy” substrate.VNAE5071C is devised to test patch. Improved Gain, Directivity and Bandwidth in contrast with declined Reflection coefficient and VSWR together with multiband frequency responses are the characteristics of slot antenna.
I. INTRODUCTION In practical applications, narrow bandwidth is the major drawback of microstrip antenna. Of late, several broadband or bandwidth techniques such as coplanar gap, coupled patches, use of thick air or foam substrate etc are employed. It is advised to quote that bandwidth can also be improved by loading of suitable slots together with radiating edges of patch. To curb the impedance of microstrip antenna, we use multiple slots also. The introduction of slots disturbs the path of the current in the patch and thus brings about dual band properties in the patch antenna. Microstrip patch antennas possess certain type of waves along the radiated waves that greatly reduce the performance of the antenna. These waves which enormously impact on the performance of patch antennas are called surface waves. The guided waves that are apprehended within the substrate and partly radiated and reflected back at the substrate edges are called surface waves. The various slot shapes are available to fulfil the requirement of improvement in bandwidth. The etching of U slot on the Microstrip patch is considered to be a simple design .Such a design does not make use of stacked or coplanar parasitic patches because either of these increases the thickness or the lateral size of the antenna. So, while changing the current distribution on the Microstrip patch enhancing the impedance bandwidth with sometimes more than one resonant frequency are obtained. The loading of slot on the radiating patch results in increase of the current length that results in lowering fundamental resonance
frequency which corresponds to reduced antenna size when compared to conventional patch antenna for a given resonant frequency II. DESIGN CONSIDERATION A. Calculation of Width ( ): Width of the patch antenna is calculated by using =
(1)
)
(
Where = 3 ∗ 10
/
B. Calculation of Actual Length (L): The effective length of patch antenna depends on the resonant frequency ( ).
= Where
(2a) =
+
1 + 12
(2b)
Actual length and effective length of a patch antenna can be related as
=
− 2∆
(3)
Where ∆ is a function of effective dielectric constant and the width to height ratio
= 0.412
(
. )
(
.
. )
.
(4)
C. Calculation of Inset feed Depth ( ): = 10 93.187
0.016922 − 682.69
+ 0.13761 − 6.1783 + + 2.561.9 − 4043 + 6697
D. Calculation of feed width (
(5)
):
To achieve 50Ω characteristic impedance, the required feed width to height ratio is computed as
= ≤ 2 − 1 − ln(2 − 1) +
ln( − 1) + 0.39 −
.
≥ 2
B. Reflection coefficient: A minimum Reflection coefficient -41.01dB was observed at 2.7 GHz and -34.92 dB was observed at 3.26 GHz as shown in fig 3.
(6a) +
Where =
=
0.23 +
.
(6b) (6c)
√
=
∗ (
∗
(7)
)
F. Miter Bend designed equation (D):
=
√2 ∗ (0.52 + 0.65 ∗
.
10
-10
0
2
4
6
8
(8)
Simulation -S11 (dB)
-50
= √2 − III. RESULTS AND DISCUSSION A slot of 10mm is introduced at the centre of the patch as 1st iteration and a set of four slots of 4mm are introduced around the four corners as 2nd iteration. The simulated structure and fabricated antenna as shown in fig 1 and fig 2.
Fig. 3 Reflection coefficient plot C. VSWR: A minimum VSWR of 1.02 was observed at 2.77 GHz and 1.23 was observed at 6.24 GHz as shown in fig 4 100
Frequency (GhZ)
A. Four element array: Structure:
12
Measured- S11(dB)
-40 ∗ )
10
-20 -30
D = w√2 (
20
0
E. Calculation of notch gap ( ): .
Frequency (GhZ)
30
80 60
VSWR-Measured
40 VSWR-Simulated 20 0 0
2
4
6
-20 Fig. 1 Structure of the 4 element Array Antenna -40 Fig. 4 VSWR plot
Fig. 2 Fabricated of the 4 element Array Antenna
8
10
12
D. Radiation Pattern: The simulated radiation pattern as shown in fig 5
E. Gain(dB): The simulated Gain as shown in fig 6
Fig. 5 Radiation plot
Fig. 6 Gain plot
Results of 4 elements patch array with multiple rectangular slots Type of patch with feed network
four element slot antenna array with mitered bend feed network
Resonant Frequency (GHz)
Reflection Coefficient (S11) (dB)
Gain (dB)
VSWR
Simulated
Measured
Simulated
Measured
Simulated
Measured
1.48 2.13 2.74 4.32 5.52 6.28 6.89
1.12 1.81 2.16 4.6 5.97 6.25 6.59
-13.89 at 1.48 GHz -18.07 at 2.13 GHz -41.01 at 2.7 GHz -34.92 at 3.26 GHz -13.10 at 4.32 GHz -11.17 at 5.5 GHz -21.88 at 6.28 GHz -19.08 at 6.89 GHz
-8.65 at 1.12 GHz -12.3 at 1.81 GHz -15.91 at 2.16 GHz, -14.35 at 4.6 GHz, -25.66 at 5.9 GHz, -21.03 at 6.25 GHz, -16.2 at 6.59 GHz,
1.50 at 1.45 GHz, 2.10 at 2.11 GHz, 1.02 at 2.77 GHz, 1.82 at 3.24 GHz, 1.58 at 4.29 GHz, 1.76 at 5.5 GHz, 1.23 at 6.24 GHz, 1.29 at 6.89 GHz,
2.33 at 1.12 GHz, 1.7 at 1.81 GHz, 1.4 at 2.16 GHz, 1.45 at 4.6 GHz, 1.2 at 5.9 GHz, 1.2 at 6.25GHz, 1.4 at 6.59 GHz,
IV. CONCLUSION It can be summed up that multibands are developed besides the resonance frequency; input impedances are significantly affected by loading of patch with rectangular slot, in addition a drastic increase is seen in the bandwidth. REFERENCES [1] Sharma, B.S. and Panwar, S. “Dual U-slot Microstrip Patch Antenna With Enhanced Bandwidth,” International Journal of Science and Research (IJSR), Volume 2 Issue 8, pp. 145-147, August 2013. [2] Balanis,C. A. Antenna Theory, John Wiley & Sons, Inc. , 1997. [3] Motin, M. A., Hassan, Md. Imran and Islam, Md. S., “Design And Simulation Of a Low Cost Three Band Microstrip Patch Antenna for the Xband, Ku- Band and K- Band Applications,” 7th International Conference on Electrical and Computer Engineering, pp.397-400, 20-22 December, 2012 IEEE. [4] Harleen Kaur, Balwinder Singh Dhaliwal “ Numerical Analysis of Slot Position of Rectangular U Slot Microstrip Patch Antenna “ I.J. Wireless and Microwave Technologies, Volume 6 Issue 8, pp. 29-39, May 2016. [5] Sun Xin, Zeng Gang, Hong-Chun, Y., & Yang, L. A compact quadband CPW-fed slot antenna for MWiMAX/WLAN applications. IEEE Trans Antenna Wireless Propagat Lett, 11, 2012, 395–398.
Simulated
9.65
[6] Wong, K. L. (2002). Compact and Broadband Microstrip Antennas. New York: John Wiley and Sons Inc. [7] D.Prabhakar, P. Mallikarjuna Rao, M.Satyanarayana” Design and Performance Analysis of Microstrip Antenna using different Ground Plane Techniques for WLAN Application ” I.J. Wireless and Microwave Technologies, Volume 6 PP.48-58, July 2016.
