International Journal of Science and Engineering Volume 1, Number 1-2013 PP-34-40 IJSE Available at www.ijse.org ISSN: 2347-2200 Truncated Rectangular Microstrip Antenna for Wide band Samarjeet Singh *, Bhaskar Gupta, 1 Anil Kumar 2 *Department of Electronics & Communication Engineering, BBDIT,Ghaziabad 1 Department of Electronics & Communication Engineering, BBDIT,Ghaziabad 2 Department of Electronics, BBDIT,Ghaziabad Email: bhaskar.pics@gmail.com Abstract:-Wide band truncated rectangular microstrip antenna with H slot loaded and defected ground plane structure is presented in this paper to increase the bandwidth. It is found that the impedance bandwidth of a microstrip antenna could be enhanced considerably when a defected ground structure is used.the band width of a truncated rectangular microstrip antenna with H slot is 21.2% whereas after adding the slot in the ground plane of a rectangular microstrip antenna with H slot the bandwidth is increase up to 29.0% ranging from 1.76 to 2.34 GHz. The radiation pattern has acceptable response at both E&H plane. The antenna is design at FR4 glass epoxy substrate with dielectric constant 4.4 fed by a coaxial feeding technique. Detail of the proposed antenna and the simulated results are presented. Keuwords - bandwidth, broadband, microstrip antenna (msa), return loss, truncated rectangular microstrip antenna (trmsa). 1. INTRODUCTION The traditional MSA is inherently a narrow band structure.however bandwidth enhancement is usually demanded for practical applications. In addition, applications in present day s mobile communication systems usually require smaller antenna size in order to meet the miniaturization requirements of mobile units. Thus size reduction and bandwidth enhancement are becoming major design considerations for practical applications of microstrip antennas. According to open literature, several designs have been investigated and reported to improve the B.W. MSA consists of a dielectric substrate with a ground plane on the other side. Due to its advantages such as low profile planner configuration, low costs, light weight and capability to integrate with microwave wave integrated circuits technology, the microwave antennas is very well suited for applications such as wireless communication system, pagers, cellular phones, satellite comm. and radar systems. In this paper, Wide band truncated rectangular microstrip antenna with H slot loaded and defected ground plane structure is proposed to increase the bandwidth. The band width of a truncated rectangular microstrip antenna with H slot is 21.2% whereas after adding the slot in the ground plane of a rectangular microstrip antenna with H slot the bandwidth is increase up to 29.0% ranging from 1.76 to 2.34 GHz. It was reporter that defected ground structure was used to suppress higher order harmonics and to increase impedance BW. For a good impedance matching over a wide frequency range, notches are introduced on the two corners of the rectangular patch antenna as shown. Using IE3D software the return loss and the bandwidth are calculated. II. ANTENNA DESIGN SPECIFICATION Figure -1 shows the truncated rectangular microstrip patch antenna with H slot. The design parameters for the TRMSA structure, length of patch (L) is 47mm, width (W) is 62 mm. and remaining dimensions are ISSN:2347-2200/V1N1/pp-34-40/ IJSE
Truncated Rectangular Microstrip Antenna for Wide band shown in fig1.the dielectric constant (Єr) of the substrate is 4.4mm and the thickness of the dielectric substrate is 6.4 mm. The patch is printed on inexpensive glass epoxy FR4 substrate. The 50-ohm coaxial cable with SMA connector is used for feeding. The proposed patch antenna gives wide bandwidth having resonance frequency f 0 = 2.26 GHz with impedance Bandwidth equal to 21.2%, in the frequency range of 2.02 GHz to 2.5 GHz, at appropriate feed point location. Figure 2 show the variation of return loss with frequency for the proposed design, Figure 3 shows the VSWR Vs frequency, Fig4 & Fig5 shows the impedance loci and radiation pattern for the proposed design respectively. Figure 6 shows the directivity vs. frequency graph, at resonance frequency 2.26 GHz the directivity is 7.9dBi, the typical value of directivity for Microstrip patch antenna should be 5-8 dbi. Fig1- truncated rectangular microstrip patch antenna with H slot. Fig.2- Variation of return loss with frequency for design 1. ISSN:2347-2200/V1N1/pp- 34-40/ IJSE
Samarjeet Singh et al. Fig 3- Variation of frequency Vs. VSWR for design 1 Fig. 4- Impedance Loci for design 1 ISSN:2347-2200/V1N1/ pp-34-40/ IJSE
Truncated Rectangular Microstrip Antenna for Wide band Fig 5- Radiation pattern for design-1 Fig 6- Directivity Vs. Frequency for design-1 With the same design parameters an effort is made to enhance the bandwidth by modifying the ground plane structure. Fig-7 shows proposed design 2 with defected ground plane structure of 5mm slot loaded in ground plane of design 1, truncated rectangular microstrip patch antenna with H slot. With this modification there is a good enhancement in BW up to 29.0% having resonance frequency equal to 2.05 GHz in the frequency range 1.76 to 2.34 GHz, For this design the dimensions would be given as: length of patch L = 47 mm, width of patch W=62 mm, with a slot cut of width 5 mm as shown. For design 2, Fig 8 shows the variation of return loss with frequency, Figure 9 shows the VSWR Vs, frequency, Fig 10 & Fig 11 shows the impedance loci and radiation pattern for the proposed design respectively. Figure 12 & 13 shows the directivity Vs. frequency and 3D view for design 2. Fig.7- defected ground plane with proposed design 1. ISSN:2347-2200/V1N1/pp- 34-40/ IJSE
Samarjeet Singh et al. Fig. 8- Variation of return loss Vs frequency for design 2. Fig 9- Variation of frequency Vs. VSWR for design2. Fig. 10- Impedance Loci for design 2. ISSN:2347-2200/V1N1/ pp-34-40/ IJSE
Truncated Rectangular Microstrip Antenna for Wide band Fig11- Directivity VS. Frequency for design 2. Fig 12- Radiation pattern for design-2. ISSN:2347-2200/V1N1/pp- 34-40/ IJSE
Samarjeet Singh et al. Fig 13-3D view for design 2. III.CONCLUSION It is concluded that the designed antennas exhibits wide band operation due to its multi resonance nature. Wide band has achieved by inserting slot on ground plane. By this impedance bandwidth enhancement method the antenna obtain the 10-dB return loss from 1.76 GHz to 2.34 GHz yielding 29.0% enhancement when compared with that of H slot loaded truncated rectangular microstrip patch antenna. The antenna characteristics and radiation pattern are satisfactory for most of the wireless systems. REFERENCES 1. C. A. Balanis, Antennas theory analysis and design, 2 nd edition, John wiley &sons. Inc, 1997 2. Kin Lu Wong, Compact & broadband Microstrip antenna, John wiley & Sons. Inc, 2001. 3. Kumar, G. and K. P. Ray, Broadband Microstrip Antennas, Artech House, USA, 2003. 4. D.K. Srivastava, J.P. Saini, D.S. Chauhan, Wide band electromagnetically coupled coaxial fed slot loaded stacked patch antennas, (IJEST-NG), Vol.3, PP 154-159, 2011. 5. H. F. AbuTarboush, H. S. Al-Raweshidy, and R. Nilavalan, Bandwidth Enhancement For Microstrip Patch Antenna Using Stacked Patch And Slot, IEEE, 2009. 6. Amit A. Deshmukh, and K. P. Ray, Compact Broadband Slotted Rectangular Microstrip Antenna, IEEE Antennas And Wireless Propagation Letters, Vol.8, 2009. 7. Chow-Yen-Desmond Sim, Wen-Tsan Chung, and Ching-Her Lee, Compact Slot Antenna For USB Applications, IEEE Antennas And Wireless Propagation Letters, Vol.9, 2010. 8. Ka Hing Chiang, and Kam Weng Tam, Microstrip Monopole Antenna With Enhanced Bandwidth Using Defected Ground Structure, IEEE Antennas And Wireless Propagation Letters, Vol.7, 2008. ISSN:2347-2200/V1N1/ pp-34-40/ IJSE