H And U-Slotted Rectangular Microstrip Patch Antenna

Transcription

1 H And U-Slotted Rectangular Microstrip Patch Antenna Bharat Rochani 1, Sanjay Gurjar 2 1 Department of Electronics and Communication Engineering, Engineering College Ajmer 2 Department of Electronics and Communication Engineering,Bhagwant University Ajmer bharat.rochani@gmail.com, ersanjay86@yahoo.in Abstract- The microstrip patch is one of the most preferred antenna structures for low cost and compact design for wireless system. Dual and triple band antennas are of a relative interest since they can support multiple communication systems. In this paper we present designs of compact small size microstrip antennas suitable for dual and triple band operations. By loading properly arranged slots on a rectangular microstrip patch, dual and triple frequencies and broadband operations of a single feed rectangular patch is achieved. Dual and triple frequency operation is achieved by loading U and H slots in rectangular patch. The impedance bandwidth of 150MHz, 1.26GHz band for U slot and 154MHz, 484MHz, 396MHz for H slot is obtained in the proposed designs Keywords Slotted Microstrip Antenna, Radiation Pattern, Return Loss, HFSS I.INTRODUCTION Microstrip patch antennas are widely implemented in many Applications, especially in wireless communication. This is due to attractive features such as low profile, light weight, conformal shaping, low cost, high efficiency, simplicity of manufacture and easy integration to circuits. However the major disadvantage of the microstrip patch antenna is its inherently narrow impedance bandwidth. Intensive research has been done in recent years to develop bandwidth enhancement techniques. This technique includes the utilization of thick substrates with low dialectic constant [1] and slotted patch [2]. The use of electronically thick substrate provides limited success because a large inductance is introduced by the increased length of the probe feed. It results few percentage of bandwidth at resonant frequency. By loading some specific slot in the radiating patch of microstrip antennas, compact or reduced size microstrip antennas can be obtained [3]. The loading the slots in the radiating patch can cause meandering of the excited patch surface current paths and result in lowering of the antenna s fundamental resonant frequency, which corresponds to the reduced antenna size for such an antenna, compared to conventional microstrip antenna at same operating frequency. In this paper, rectangular microstrip antenna with H & U-shape slots proposed. The patch was mounted on substrate Rogers RT duroid 5880(tm) (thickness=.32mm) II.ANTENNA DESIGN A. H Slot RectangularPatch Antenna In this paper, the H shaped slot is cut in microstrip patch for wide band width. H-shaped slots easily formed by cutting three slots from a rectangular patch [4,5]. By cutting the slots from a patch, gain and bandwidth of microstrip antenna can be enhanced. For this proposed antenna, size of ground plane is (L X W) 90 X 100 mm and thickness of dielectric substrate is 3.2 mm with ε r = 2.2.The geometry of H slot patch antenna is shown in table 1. The geometry of rectangular microstrip patch antenna with H-slot is presented in Fig.1 with top view and Fig. 1 with 3D Geometry.

2 Table-1 The Dimensions Of The H Slot Patch In MM L W H1 H2 F H ε r W W W1 L H1 F H2 h Figure 1.Top View of H slot Patch Antenna,3D Geometry of H slot Patch Antenna Where the length and width for the rectangular microstrip patch are following: The height of the patch is Where The width of the patch is W= The length of metallic patch L=!2 # #$0.412' ( )*0.03+,-*0.264/ ( )!0.258+,-*0.8/ 2

3 B. U Slot Rectangular Patch Antenna ) $ *1 2 *!1 31* By cutting U slot onto the patch, enhance the impedance bandwidth [5]. The geometry of this proposed U slot antenna is shown in table 3. Table-2 The Dimensions Of The U Slot Patch In MM L W U1 U2 F U3 H εr W W L F U2 U1 U3 H Figure 2.Top View of U slot Patch Antenna,3D Geometry of U slot Patch Antenna IV.RESULTS AND DISCUSSION A. H Slot Rectangular Slot Antenna The proposed antenna is simulated using HFSS 11[6] software. Table-3 SIMULATED RESULTS FOR H SLOT PROBE FEED PATCH ANTENNA Return Patch Shape Frequency Gain Bandwidth Loss dB 3.47%( GHz) H Shape dB 7.81%( GHz) db dB 3.9%( GHz)

4 RETURN LOSS GAIN Figure 3. Return loss vs. Frequency curve, Rdiation Pattern B. U Slot Rectangular Patch Antenna Table-4 Simulated Results For U Slot Probe Feed Patch Antenna Patch Frequency Gain Return Bandwidth Shape Loss U Shape dB 5%( GHz) db -29dB 11%( GHz) RETURN LOSS GAIN Figure 4. Return loss vs. Frequency curve,. Rdiation Pattern

5 IV.CONCLUSIONS In this paper, the small dual band for U slot and triple-band for H-slot microstrip patch antennas are designed. The parameters, gain and return losses are shown. The probe feed technique and HFSS11 [6] for simulation are used. The gain and return losses were good for these bands. The antenna is designed to be used in WiMax and multi-band applications. V. REFERENCES [1] James, J.R. and Hall, P.S.: Handbook of Microstrip Antennas (Peter Peregrinus) [2] Constantine A. Balanis : Antenna Theory, Analysis and Design (John Wiley & Sons) [3] D.M. Pozar, "A reciprocity method of analysis for printed slots and slot coupled microstrip antennas", IEEE Transactions on Antennas Propagat., Vol. AP34, pp , December [4] Noori, O.; Chebil, J.; Islam, M.R.; Khan, S., Design of a triple-band h slot patch antenna 2011 IEEE International RF and Microwave Conference (RFM), December [5] K. F. Lee1, K. M. Lu, K. M. Ma, and S. L. S. Yang1, On the Use of U-Slots in the Design of Dual-and Triple-Band Patch Antennas IEEE Antennas and Propagation Magazine, Vol. 53, No.3, June [6] Ansoft Designer,