A New Linear Micro strip Patch Antenna Array

A New Linear Micro strip Patch Antenna Array

P.V.A.Anantha Varma1

Final Year Student, Department of ECE, M.V.G.R College of Engineering, Vizianagaram, AP-535005, India

P. Chaitanya Gopal1

Final Year Student, Department of ECE, M.V.G.R College of Engineering, Vizianagaram, AP-535005, India

P.Kartheek1

Final Year Student, Department of ECE, M.V.G.R College of Engineering, Vizianagaram, AP-535005, India

Abstract In this paper the design of inset feed Linear Micro strip patch antenna array has been proposed. It has been observed for a printed antenna array at frequencies of 2.9GHz and 7.7GHz. The Ansoft HFSS 13.0 software is used to simulate the antenna array. The dimension of each patch antenna in the array of four antennas is 25mm×18mm. The characteristics of the antenna array are determined in terms of Return loss, VSWR and gain. The array produces a return loss of – 15.70dB at 2.9GHz and a return loss of – 18.92dB at 7.7GHz. The VSWR values are 1.39:1 at 2.9GHz & 1.25:1 at 7.7GHz.The

overall obtained gain is around 3.8 dB.

KeywordsGain, Micro strip patch, Return loss, VSWR and Inset feed.

I.INTRODUCTION

In many of the modern applications like wireless communication system requires simple structure antennas with a low profile, light weight and high gain to give better reliability, mobility, and high efficiency characteristics [1, 2]

Micro strip antennas are easy to fabricate and are light weight with low profile. The applications are limited by poor efficiency, gain and narrow impedance bandwidth [3].these drawbacks occur due to the impedance mismatch and to overcome this feed should be given where the resonant resistance and feed-line resistance are equal. Micro strip structure design requires understanding of the mathematical relations and also its applications [3].

In many applications, in order to provide high efficiency the micro strip patch antenna is fed using either

coaxial probe feed or insert micro strip line as both are direct contact methods [4]. If we consider a single antenna, it resembles a cavity backed antenna as proposed by saloon [5] which is nothing but a suspended antenna which is designed to get high bandwidth and gain. This proposed antenna suffers from impedance mismatch which can be overcome by the inset feed. The Inset-fed Micro strip antenna with a planar feed configuration provides a method for impedance control that is required. This antenna provides the advantages of printed circuit technology. These advantages of Micro strip antennas make them popular in many wireless communication applications such as satellite communication, radar, medical applications, etc. [6]

Here we use an array of antennas instead of a single antenna in order to improve its gain. An array is one in which the current is spitted up in between the antennas in the array and here we use an array of four antennas. In many of the cases like high gain arrays we use an inset feed which provides high efficiency where the input impedance is determined by the inset length.

In this paper we propose a method for designing the inset feed section of the array to reduce the mismatch between the patch and feed network. The input impedance of the inset feed micro strip patch antenna mainly depends on the inset distance A and to some extent on the inset width [7] and in some cases the inset gap is taken the same width as the feed line [8].

1. ANTENNA DESIGN

   The patch antenna was designed depending on the basics of the transmission line model (TLM). The width of the patch can be calculated by the formula

   Where is the substrate dielectric constant, W is the width of the patch and h is the height of the substrate. An effective dielectric constant reff is used which is defined as the dielectric constant of the uniform dielectric material and given by,

   resonating frequencies (2.9 and 7.7GHz) operating antenna. The proposed antenna is simulated using Ansoft HFSSv13 software and is shown in Figure 2.

   The following table gives the dimensions of the designed antenna array,

   Table: The antenna dimensions (in mm)

   Parameter	Size (mm)	Parameter	Size (mm)
   W	25	D	28.5
   L	18	P	20
   Wf	6	Q	15
   A	5	R	16
   B	7.5	Lg	25
   C	75	Wg	150

   Parameter	Size (mm)	Parameter	Size (mm)
   W	25	D	28.5
   L	18	P	20
   Wf	6	Q	15
   A	5	R	16
   B	7.5	Lg	25
   C	75	Wg	150

   [ ]

   [ ]

   [ ]

   The patch used in our model is a square patch, so the length and width are same. The dimensions of the patch are extended to account the fringing effect; the extension is given by,

   ( (

   ) ( )

   ) ( )

   Since the length has been extended on each side of the patch, the effective length is given by

   Figure 1(a): Patch

   Patch resonant length L is given by,

   The configuration of the double-band antenna is shown in figures 1(a) and 1(b). The array of rectangular patches is the radiating element shown in figure 1(a). We used a 1.6 mm-thick FR4 epoxy substrate and = 4.4. The partial ground plane is located on the backside of the dielectric substrate, as shown in Figure 1(b). The array along with the ground plane gives resonance in the 2.85 to 2.96 and 7.58 to 7.78 GHz bands. The combination of the array of rectangular patches and ground plane results in Double band

   Figure 1(b): Ground

   Figure 5: 3D Gain of the array

   Figure 2: Simulated antenna using HFSS

   Name X Y m15.00 130.0000 -19.7354

   m2 180.0000 3.7169

   m3 230.0000 -20.2891

   -0.00

   -5.00

   2D GAIN

   m2

   HFSSDesign1 ANSOFT

   Curve Info dB(GainTotal)

   Setup1 : LastAdaptive Freq='2.4GHz' Phi='0deg'

2. SIMULATED RESULTS

   The characteristics of patch antenna and arrays are determined in terms of Return loss, VSWR, Radiation pattern and Gain using HFSS. The gain obtained is 3.8dB.

   -10.00

   dB(GainTotal)

   dB(GainTotal)

   -15.00

   -20.00

   -25.00

   m1

   0.00 125.00

   Theta [deg]

   m3

   250.00 375.00

   The return losses cross -10dB over 2.85 to 2.96 GHz and

   7.58 to 7.78 GHz and the resonating frequencies are 2.9 and

   7.7 GHz. The 2D-gain observed in the structure shows a maximum of 3.71dB and a minimum of -20.28 dB. VSWR

   Name Theta Ang Mag m1 175.0000 175.0000 3.8108

   m3 350.0000 -10.0000 2.9589

   Figure 6: 2D- GAIN

   Radiation Pattern

   0

   m3

   HFSSDesign1 ANSOFT

   Curve Info

   dB(GainTotal)

   obtained at 2.9 GHz and 7.7 GHz are 1.39:1 and 1.25:1 respectively. The characteristics can be oserved from the simulated results as shown below

   m4 265.0000 -95.0000 -24.7072

   m5 85.0000 85.0000 -25.2022

   -90

   -60

   -30

   30

   -2.00

   -9.00

   60

   -16.00

   -23.00

   m4 m5

   90

   Setup1 : LastAdaptive

   Freq='2.4GHz' Phi='90deg'

   dB(S

   t(Recta

   Curve I ngle5_

   fo T1,Rect

   angle5_

   T1))

   Setu

   p1 : Sw

   eep

   m1 m3

   m4

   m6

   Name m1

   X 2.8498

   -10.

   Y 0830

   m2

   2.9000

   -15.

   7052

   m2

   m3

   2.9592

   -10.

   0415

   m4 m5

   7.581 7.7000

   -10 -18.

   0329 9273

   m6

   7.7879

   -10.

   1060

   m5

   dB(S

   t(Recta

   Curve I ngle5_

   fo T1,Rect

   angle5_

   T1))

   Setu

   p1 : Sw

   eep

   m1 m3

   m4

   m6

   Name m1

   X 2.8498

   -10.

   Y 0830

   m2

   2.9000

   -15.

   7052

   m2

   m3

   2.9592

   -10.

   0415

   m4 m5

   7.581 7.7000

   -10 -18.

   0329 9273

   m6

   7.7879

   -10.

   1060

   m5

   Return Losses

   0.00

   HFSSDesign1 ANSOFT

   n

   -2.50

   -5.00

   -120

   120

   dB(St(Rectangle5_T1,Rectangle5_T1))

   dB(St(Rectangle5_T1,Rectangle5_T1))

   -7.50

   -10.00

   -150

   m1

   -180

   150

   -12.50

   -15.00 3 .

   -17.50

   Figure 7: Radiation Pattern

3. Conclusions

   -20.00

   1.94 2.25 3.50 4.75 6.00 7.25 8.50 9.50

   Freq [GHz]

   Figure 3: Return Losses

   In this paper, the design of inset feed Linear Micro strip patch

   antenna array has been proposed. It has been observed for a printed antenna array at frequencies of 2.9GHz and 7.7GHz.

   16.00

   14.00

   12.00

   VSWRt(Rectangle5_T1)

   VSWRt(Rectangle5_T1)

   10.00

   8.00

   6.00

   4.00

   Name X Y

   m1 2.9000 1.3922

   m2 7.7000 1.2552

   VSWR

   HFSSDesign1 ANSOFT

   Curve Info VSWRt(Rectangle5_T1)

   Setup1 : Sw eep

   The Ansoft HFSS 13.0 software is used to simulate the antenna array. The dimension of each patch antenna in the array of four antennas is 25mm×18mm. The characteristics of the antenna array are determined in terms of Return loss, VSWR and gain. The array produces a return loss of -15.70dB at 2.9GHz and a return loss of -18.92dB at 7.7GHz. The VSWR values are 1.39:1 at 2.9GHz & 1.25:1 at 7.7GHz.The overall obtained

   gain is around 3.8 db.

   2.00 m1 m2

   0.00

   1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00

   Freq [GHz]

   Figure 4: VSWR Curve

4. REFERENCES

1. Kashwan K R, Rajesh Kumar V, Gunasegaram T and Shankar Kumar K R, Design and Characterization of Pin Fed Micro strip Patch Antennae, IEEE proceedings of FSKD2011

2. M. T. I. Huque, et al., "Design and Simulation of a Low- cost and High Gain Micro strip Patch Antenna Arrays for the X-band Applications," in International Conference on Network Communication and Computer ICNCC 2011, New Delhi, India., March 21-23, 2011.

3. Ramesh Gharg, Prakash Bhartia, Microstrip Antenna design Handbook, Artech House, 2000

4. Rodney B Waterhouse, Microstrip Patch Antennas, A Designers Guide.

5. N.U. Lau' and R. Sloan, Suspended Microstrip Patch Antenna with Ground-shield Tapered Suspended Stripline Feed, 33rd European Microwave Conference IEEE – Munich 2003

6. N. Kanniyappan, Dr.R. Indra Gandhi, Design and Analysis of Micro strip Patch Antenna Feeding Techniques,IEEE proceedings of International Conference on Computational Intelligence and Computing Researcp011

7. M. Ramesh and YIP KB, Design Formula for Inset Fed Microstrip Patch Antenna, Journal of Microwaves and Optoelectronics, Vol. 3, No 3, December 2003.

8. Y.T.Lo, S. W. Lee, Antenna Handbook, Vol 2

Electronics.

P.V.A.ANANTHA VARMA was born

in Vizianagaram district in India in 1993. He is in his final year of Bachelors in Technology, majoring in Electronics and Communications from a JNTU Affiliate College, MVGR. His areas of interest are Antennas, embedded systems and digital electronics.

Pathivada Kartheek was born in Visakhapatnam, district in India in 1992. He is pursuing B. Tech in Electronics and Communication from M.V.G.R College of Engineering, Vizianagaram affiliated to JNTU Kakinada. His areas of interests are Antennas, Wireless Communication, Embedded Systems and Digital

embedded systems.

P.CHAITANYA GOPAL was born in Visakapatnam district in India in 1993. He is pursuing his B. Tech at the MVGR College of engineering. His specialized engineering stream is electronic communication. His areas of interest are digital image processing, Antennas,