MICROSTRIP RECTANGULAR PATCH ANTENNA USING COPLANAR PARASITIC ROD ELEMENTS WITH SUBSTRATE INTEGRATED FEEDING LINE TECHNIQUE

Microstrip antenna technology is fast growing technology in present days there are broadly used in mobile communication and satellite communication. The microstrip antennas are very low cost and low profile and ease fabrication. However, the bandwidth utilization is the drawback for this system. Now proposed methodology can be reduced that drawback and provide efficient bandwidth utilization factor in proposed method design a microstrip rectangular patch antenna using co-planar parasitic rod elements with substrate intergrading feeding line technique. This proposed method, microstrip rectangular patch antenna is designed for the enhancement of bandwidth, Improvement in front to back ratio, reduction in losses and high-quality factor and power handling capability. The 5072 SRIVASTAVA, CHOUDHARY, SHARMA, JHA, KUMAR, BUTUL, KAPSE proposed method enhances the bandwidth ratio from 4% to 18% it shows that the proposed method gives the best results compared to the existing approach. The simulation and 3D plot results can be obtained from Ansoft HFSS (High-frequency structure simulator) Software.


INTRODUCTION
A microstrip antenna is a wide beam narrowband antenna [1] developed easily by printed circuit technology such as fabricated [2] by etching the antenna element pattern in the metal trace bonded on an insulating dielectric substrate, which procedures a radiating element and another continuous metallic layer on the other side of substrate as ground plane [3]- [23]. Nor only the one shape we use different shapes like square, rectangular, circular, and elliptical shapes also can be used as a radiating patch. As a replacement for of dielectric substrate, we use dielectric spacers [4] for some of the microstrip antennas which give broader bandwidth, but which are more costly. The popularity of microstrip antennas [6] has increased over the past few decades, and it has become a major topic of research for academia and industry. Microstrip antennas offer some advantages such as low profile, low cost, ease of fabrication and wrapping the antenna on a flexible substrate are few among them. Due to its structure and small volume, it finds application in the fields of communication [7], Aeronautics and Medical (Hyperthermia).
The proposed method of this paper is using coplanar parasitic road elements design a microstrip rectangular patch antenna. The effect of parasitic road element [8] on the radiation characteristics of a microstrip patch antenna is investigated that operates in the dominant mode and also effect on the front-to-back ratio of the microstrip patch antenna [9]. For adding coplanar parasitic road elements to designing of microstrip antenna a farther more technique is used that is substrate integrated feeding line technique [10]. This proposed method can enhance the bandwidth utilization.  Measured results indicate that the array can achieve a gain of 17.6 dB at 41.5 GHz and the first side lobe levels are -24.1 dB in the E-plane and -20.4 dB in the H-plane. The holistic FTBR is better than 27 dB in both planes. Z to 3.5 GHz having a fractional bandwidth of 74.5%.

Parasitic Patch Configuration
In Parasitic elements are leading to a tuned response that is designed in resonate close to driven radiator element in resonant frequency. An impedance bandwidth of the antenna is effective wider, and it is termed as a double resonance phenomenon technique, and that is the result. A wider effective impedance bandwidth of the antenna is the result, and it also termed as double-resonance phenomenon technique. With this same design. To maximize the substrate thickness; a double substrate layer is used that leads to excitation of surface waves.
The patch width is formulated as Where, fo = specified central frequency where is the effective extended length because at the rectangular patch edges a parasitic effect is obtained.
µ ∈ are the permeability and permittivity in free space, ε rp are the effective permittivity of the patch ε = The second step is to determine the width d of the gap. The two reflection poles can be appropriately adjusted by the gap width d, aiming to realize a dual-pole wideband performance.

a. Two layers of Substrate in parasitic patch
A less percentage is enhanced in bandwidth with a one-layer substrate. It improves the BW (bandwidth) with an effective result, and antenna surface is minimized in a double layer of the substrate compared to the single patch. A perfect E boundary is assigned for a plane and the ground.
Vacuum is used for the air box, and RT/duriod 5880 (TM) is used for substrate1. We used similar

Co-Planar Parasitic Rod elements
A conventional Microstrip Antenna with parasitic rod elements adjacent to the radiating edges of Microstrip antenna is done to improve Front-To-Back Ratio. Length of parasitic elements is kept identical to the length of the radiating side of a patch antenna. A microstrip antenna with a finite ground plane produces more back radiation from the edges of the antenna owing to a surface wave diffraction of the ground plane. To revoke the diffracted energy from edges of a ground plane, parasitic elements length is kept identical to that of the finite ground plane. By designing a conventional microstrip patch antenna, with a full metallic ground plane, the effect of the parasitic rod element on the radiation characteristics of a microstrip patch antenna is investigated that operates in the dominant mode (TM10). By using hollow parasitic rods and varying the radius of the rod, the effect of parasitic rod elements was investigated on the front-to-back (FTBR) ratio of the microstrip patch antenna, In the back-lobe region of the microstrip patch antenna, the magnitude of diffracted surface waves by the E-plane edge is much higher than the magnitude of surface wave diffracted by the H-plane edge. The field reflected by rod elements creates a second field for cancelling the antenna's field at the back side of a patch antenna.

Substrate Integrated waveguide Design techniques
These devices are a form of the dielectric-filled waveguide (DFW), so DFW is a starting point.
For TE10 mode, the waveguide cut off frequency is not affected as the dimension "b" is not mandatory. It only reduced the dielectric loss to the substrate consists of thickness unknown. For a rectangular waveguide, cut off frequency of arbitrary mode is found by the following formula Where, c = speed of light m, n = mode numbers a, b = dimensions of the waveguide For TE10 mode, the more shortened version for this formula For dielectric-filled waveguide (DFW) with an equal cut-off frequency ad is is The determined dimension "a" for the DFW, we can now pass to the proposal equations for substrate integrated waveguide.
Where, d = diameter p = pitch (distance between the vias) The following two situations are mandatory in SIW Design Where guided wavelength is    As in the case of the microstrip line feeding, by spurious radiation of the feeding part, the radiation design of the antenna is unchanged. The simulation results proved that the antenna array covers the 18GHz ISM band and radiates with a low side lobe level and a good front-to-back ratio

CONCLUSION
The design of microstrip rectangular patch antenna using coplanar rod parasitic elements that Improves the front to back ratio and reduction in losses. The design by two layers Substrate coupled with Integrated Substrate waveguide of coplanar parasitic Rods increases the power handling capacity and increase in quality factor. The simulation outcomes proved the antenna array covers the 18GHz ISM band and radiates with a low side lobe level and a good front-to-back ratio.
By decreasing the S parameter value, the dielectric losses and the conductor losses are minimized.
The frequency in wideband avoids the repeated electromagnetic analysis.