The efficiency is also increased with a lower value for the permittivity. Samadhiya Return loss and Impedance Bandwidth of Rectangular microstrip Patch Antenna with proposed metamaterial structure is shown in Fig. Samadhiya 4 Simulation Results In this section, the simulated results are presented. Increasing the height does induce surface waves that travel within the substrate which is undesired radiation and may couple to other components. International Journal of Engineering and Technology, 1 3 2012 205-216 ©Science Publishing Corporation www. The simulated S-Parameters are then exported to Microsoft Excel Program for verifying the Double-Negative properties of the proposed metamaterial structure.
. Schultz, Composite medium with simultaneously negative permeability and permittivity, Phys Rev Lett 84 2000 , pp. The following equation roughly describes how the bandwidth scales with these parameters:. The wider the patch becomes the lower the input impedance is. Equation 1 above can be solved for L to illustrate this: Hence, if the permittivity is increased by a factor of 4, the length required decreases by a factor of 2. One technique is to use a substrate with a very high permittivity.
Particularly in cell phones, the designers are given very little space and want the antenna to be a half-wavelength long. After the fabrication of proposed antenna the antenna parameters like return loss and bandwidth are measured on the spectrum analyzer. It has also been seen that with these improvements this structure also possesses double negative properties within the operating frequency ranges. Increasing the height also increases the efficiency of the antenna. The Dimensional view of this design is shown in the Fig. In spite of having a lot of advantages low profile, low cost and omni directional radiation patterns etc.
The impedance of the antenna increases with higher permittivities. Marsi, Microstrip Antenna gain enhancement using left-handed metamaterial structure, progress in Electromagnetic Research M. The impedance bandwidth of the patch antenna along with the proposed metamaterial structure at 2. Using higher values for permittivity is frequently exploited in antenna miniaturization. Return loss and Impedance Bandwidth of Rectangular Microstrip Patch Antenna is shown in Fig. This work is mainly focused on increasing the potential parameters of microstrip patch antennas and analyzing the dual band operation of proposed antenna.
The permittivity of the substrate controls the fringing fields - lower permittivities have wider fringes and therefore better radiation. Along with these improvements it has also been verified that this structure satisfies Double Negative property within the operating frequency ranges. The proposed antenna is designed to resonate at 2. S-Parameter Smith Chart of Rectangular Microstrip patch antenna with proposed metamaterial structure is shown in Fig. Antenna performance can also be analysed by using different structure of patches and feeding techniques. The height of the substrate h also controls the bandwidth - increasing the height increases the bandwidth.
The parameter specifications of rectangular microstrip patch antenna are mentioned in table 1. Pendry, Negative refraction males a prefect lens, Phys Rev Lett, 85 2000 , pp. This antenna can also be operated at 2. Decreasing the permittivity also increases the antenna's. This is true in general, even for more complicated microstrip antennas that weave around - the length of the longest path on the microstrip controls the lowest frequency of operation. Dual band operation of the proposed antenna can be verified from the Graph given in Fig.
As such, this page gives a general idea of how the parameters affect performance, in order to understand the design process. First, the length of the patch L controls the resonant frequency as seen. Several researches have been done to overcome their drawbacks. This is the same principle that applies when noting that increasing the thickness of a dipole antenna increases its bandwidth. This graph has been plotted by taking the values of return loss in dB within the operating frequency range obtained from the Frequency analyzer. Smith Chart in figure 11 shows the impedance variation within the simulated frequency range.
This graph shows that there is a slight variation in operating frequencies. Setup which is used for antenna parameters measurement is shown in Fig. This is clear from Fig. According to this graph the return loss and bandwidth at 2. These are calculated from the above discussed formulae. They proved that the array of metallic wires can be used to obtain negative permittivity and split ring resonators for negative permeability. Equation 1 below gives the relationship between the resonant frequency and the patch length: 1 Second, the width W controls the input impedance and the radiation pattern see the radiation equations.
Table 1: Rectangular Microstrip Patch Antenna Specifications Dimensions Unit Dielectric Constant єr 4. . . . .
. . . . .