_{1}

This paper presents the tri-band slot loaded patch antenna for mobile communication. The antenna consists of parallel slots loaded circular disk with defected ground structure antenna (DGS). The antenna without DGS, acts like wide band antenna and bandwidth is 34.45% (3.47 - 4.92 GHz) with maximum gain of 4.97 dBi, which can be used in WiMax application. This structure has the following advantages: 1) co-axial feeding technique, which is very simple as compared to other feeding technique, 2) simple and cost effective and 3) it is more efficient than the antenna without DGS. This antenna has been analyzed using IE3D simulation software.

Slot loaded circular disk antennas, with defected ground structure for WLAN, WiMax systems, mobile phone, radar, have been reported by several researchers [

Also the concert of the antenna was investigated by the performance of the surface currents on the patch. The sizes of three parallel-slots are selected in such a way so that planned antenna can display triple frequency activities with good matching condition. Without defected ground plane, antenna works like wideband antenna with good gain which is very useful in WiMax applications. The performance of our current design is better than the results published in [

The geometry of a tri-band circular disk patch antenna with (DGS) is depicted in

Due to the fringing effects, electrically the shining patch of the antenna looks bigger than its physical size; the increment on L is given by:

where the effective (relative) permittivity is,

This is associated to the ratio of h/W. The larger value of h/W is, then the smaller effective permittivity is [

The resonant frequency for the TM_{100} mode is:

An optimized width for an efficient radiator is,

Analysis of circular disk microstrip antenna is same as that of rectangular patch apart from the effective radius and its resonant frequency. Therefore, the analysis of a circular disk patch is carried out by assuming that it is equivalent to a rectangular patch [

panded rectangular patch of dimension

If the substrate parameter (

Step 1: Using Equation (6) to get out the patch width W.

Step 2: Calculate the effective permittivity using the Equation (2).

Step 3: Compute the expansion of the length using the Equation (1).

Step 4: Determine the length L by solving the equation for L giving the solution.

From Equation (6), (f_{r}) is the resonance frequency at which the rectangular/circular microstrip antenna is to be planned. The radiating edge W, patch width is typically kept such that it lies within the variety for efficient radiation. By using the above equations we can get the values of concrete length of the patch as:

The final optimized parameters of the antenna are given in

Our aim is to design the multiband antenna with the help of parallel slots loaded circular disk patch with (DGS). First, we have designed rectangular ground plane with rectangular slot cut on copper plate. We used the FR4 dielectric on copper plate with thickness of 1.6 mm. After that we stacked a parallel slots loaded circular disk patch with ground plane. With the above idea, the guideline of the design can be shown in four steps, which are given below.

First Step: In first step, by using above formulas, we have design three parallel slots loaded circular disk patch stacked with, without defected ground. We found that the results like broadband antenna with frequency range (3.47 - 4.92 GHz) and central frequency 4.20 GHz. The individual bandwidth of the broadband antenna is 34.45% with maximum gain is 4.97 dBi. All results of broadband antenna can be simply shown in Figures 2-4.

Parameter | Value |
---|---|

Lg | 20.0 |

Wg | 30.0 |

Ls | 8.0 |

Ws | 10.0 |

R | 10.0 |

L_{1}, L_{2}, L_{3} | 10.0 |

W_{1}, W_{2}, W_{3} | 2.0 |

S | 3.0 |

FR4 | 4.4 |

h | 1.6 |

Through calculation and optimization, a broadband three parallel slots loaded disk antenna is achieved as shown in Figures 2-4. The radiation pattern of the broadband antenna is good in both E and H plane, which is shown in

We have already done more work on broadband antennas, so we are thinking about multiband antenna and then work on the next steps which are given below.

Second step: In second step, we think about the ground defected design, so we cut a rectangular slot on ground plane and stacked circular disk over a defected ground and got the multiband performance, which is my proposed antenna. The dimensions for this proposed design are listed in

The Figures 5-7, indicate that the performance of the proposed antenna is tri-band antenna. The variation of S_{11} parameter with frequency is shown in

Third step: In third step we used only two parallel slots on circular disk and ground defected is similar as earlier step. The dimensions for this design are listed in

If we used the double slots on circular disk patch the dual band antenna performance was found, which have already done in my previous work. The S_{11} and gain variation of the dual band antenna is shown in

Fourth step: In fourth step we used only single slot on circular disk and ground defected is same as earlier step. The dimensions for this design are listed in

_{11 }results between single, double and triple slots loaded on cir-

cular patch with defected ground plane. The simulated impedance bandwidths with 10 dB reflection coefficients of three different bands are 7.83%, 13.09% and 3.63% with gains, 2.30 dBi, 3.61 dBi and 0.67 dBi respectively. This is only for three parallel slots loaded on circular patch, which is shown in

In this paper, a compact triple band circular disk antenna is realized by loading three parallel slots on circular disk and rectangular slot on the ground plane. The proposed antenna has impedance bandwidth covering the C-band (4.47 - 4.83 GHz, 7.30 - 8.13 GHz) and X-band (9.53 - 9.89 GHz) frequencies. The design guidelines and appropriate equations are described and validated via IE3D simulations. The proposed antenna can be used in mobile applications.

Nagendra P.Yadav, (2016) Tri-Band Parallel Slots Loaded Circular Disk Patch Antenna for C and X-Band Applications. Wireless Engineering and Technology,07,12-23. doi: 10.4236/wet.2016.71002