Novel design of Multiband Slotted and Miniaturized Microstrip Patch Antenna for X and Ku -band Applications


 This article takes a research on a novel design of a multiband slotted microstrip patch antenna. It depicts a multi ultra wideband compressed and developed antenna with double F- slots, four rectangular slots, and side corner cuttings on the patch using partial Ground. The proposed multiband microstrip patch antenna can resonate at six unique frequencies between 8 GHz and 19 GHz in X and ku bands and execute the reflected power of − 23.8351 dB, − 32.9380 dB, − 14.6726 dB, − 22.2810 dB, − 19.0592 dB, and − 18.8137 dB at 8.6181 GHz, 12.3116 GHz, 14.1960 GHz, 15.6281 GHz, 18.1910 GHz, and 18.9447 GHz, respectively. The gained voltage standing wave ratio (VSWR) is less than 1(0.3918). A maximum directivity and gain of 6.9104 dB and 6.3769 dB is achieved at the resonating bands. Moreover, the effectiveness of the proposed multi-band patch antenna has been verified through the radiation pattern and radiation efficiency of measured results. The low size, weight, and cost of the geometry of this antenna make it entice for Radar engineering, police radars for measuring the speed of the vehicles, for military applications, for navigation intentions, and in finding out the weather forecast and Satellite broadcast communication, space-crafts, wireless computer networks, etc.


Introduction
A milestone in wireless communication systems is the execution of the Microstrip patch antenna which is progressing to accomplish the challenging demands of the new breed of antenna technology. In present-day wireless communication systems antennas are broadly used because of their inherent pro ciencies of a low pro le, lightweight, consistent design, low cost, ease of fabrication, and ease of integration with circuits. Since wireless communication devices have become a crucial part of our daily communication life, the need for a low pro le miniaturized multi-and wideband antennas has been developed. Communication systems that operate in the X-band are normally built engaging separate antennas for all bands. It is advisable to con gure a single antenna that operates in multiple frequencies for multitasking, because it is fetching more and more essential to utilize such systems in one setting [1]. A microstrip patch antenna in its uncomplicated form comprises a radiating patch on one face of a dielectric substrate and a ground plane on the contrary. With respect to the shape, microstrip antenna patches can be usual or unusual. Common regular shapes are rectangular, square, circular, elliptic, and triangular, among others. These shapes have been generally carried out and the design approaches are well established. They are employed as consistent antennas for airplanes, cars, missiles, safeguard devices, and many other implementations. Commonly shaped antennas are more frequent, because they are easy to evaluate and normally present symmetric radiation patterns. The unevenly shaped patch antenna relates to a microstrip antenna whose patch measurement is con gured to execute a speci c antenna property such as compactness, wideband characteristics, and multi resonant operation [2].The current spectrum assignment for ultra-wideband (UWB) radio communication has kindled and renewed interest in the subject of UWB antennas. Several designs have been latterly suggested for UWB antennas. However, traditional UWB antennas are "multi-narrowband" and, therefore, are not optimized to receive a single coherent signal across their entire operating bandwidth. Besides, higher-frequency cutoff performance is wanted for a UWB system to attain a better signal-tointerference ratio (SIR), with the growing demand for higher-frequency in data communications so as to bring down the interference from other indoor radio frequencies. On the other hand, the UWB antenna's performance and behavior must be stable and foreseeable over the matching band. Moreover, the denigration of escalating and contortion of the pulse, sufficient impedance matching, gain planeness and linear phase all over the entire-bandwidth are requirements of successful transmission and reception of UWB pulses. The size of the antenna, which must be retained small without compromising performance is the main another account in the design [3]. The Federal Communications Commission (FCC) systems admit the UWB wireless communication band operates at 3.1-10.6 GHz, with acutely low power ejection levels, is simply interceded with nearby communication systems such as the 3300-3600 MHz WiMax communication system, the 5150-5820 MHz and 5720-5870 MHz WLAN system, X-band between 7250-8400 MHz, Wi-Fi between 5470-5725 MHz and C-band between 3700-4200 MHz [4]. In [5] V. Bhanumathi and S. Swathi, has established an Inverted L-Shaped patch which is con gured on the top of the substrate and a U-Slot is engraved in the in nite ground plane and it is detected to be obtaining maximum return loss -24dB at the frequency range of 5 to 8GHz with a compact size of 24 × 36x 1.6 mm having altered ground structure which is determined to be appropriate for UWB applications. In . The notion of transformer is utilized for nest matching in a special microstrip feeding line and is also adequate to reach wide bandwidth with substrate dimensions 38 × 35 × 1.57mm. Microstrip Patch Antenna (MPA) employing hybrid fractal slot (Koch-Minkowski and Koch-Koch) along with partial ground plane for wideband applications. The de ciency of these above antenna review holds that the size of the ground plane and thickness of the substrate is wide and therefore antenna loss turns high and radiation e ciency becomes less. To reduce the antenna's loss and enhance the radiation e ciency is carried out by the reduction of the size of an antenna not only in the patch but also in the ground. Our paper is designed based on this idea and the simulation results show the best enhancement in radiation e ciency and lower in return loss with multi band with respect to the above analysis. The main focus being reduction and enhancement of radiation e ciency with multi-band which causes multi-task. In our novel antenna, different approaches at size reduction in the patch have been proposed such as placing double F shapes and four rectangular slots in the bottom of the patch and also having cuts on the corner of the patch left and right sides to workout multiband functions .The simulated and improved outcomes are weighed up in terms of return loss, VSWR, Gain, Directivity, and radiation e ciency. The bene t of this approach is that the return loss of the antenna gets reduced, and the radiation e ciency of the antenna gets enhanced with multi-bands. The statistical study of various antenna design variables is carried out to achieve optimum Radar and Satellite applications.

Antenna Design And Theory
The proposed antenna is possessed of a double F-Slotted patch with four rectangular slots in the bottom of the patch, cuts at left and right corners of the patch and it is fed with the microstrip line to attain 50-ohm impedance for better impedance suit. Substrate FR4-epoxy of dielectric constant 4.4 has been selected for this proposal. The height of the substrate is ℎ = 1.43 .
The length and width of the substrate (Ls×Ws) are 40mm × 26mm. Measurements of the partial ground plane (Lg×Wg) is 16.2mm×12.12mm. Diverse speci cations surveyed for this novel design are designated below in table 1.
The antenna design is con gured with double F slots having a partial Ground to encounter the essentials for the Radar and ku band implementation. This antenna has a wideband operating in the frequency range of 8-19 GHz.
A rectangular microstrip patch antenna is presented with novel deformity inserted in the patch using a partial ground plane. Fig .1(a) shows a microstrip patch antenna with the partial ground without any change in the patch. In Fig.1 (b) double F slots are combined with the radiating patch, with four rectangular slots at the bottom of the patch, two at the lower edge of the left side and two at the lower edge of the right side whose lengths and widths are upgraded to execute good consequences in antenna characteristics and preferred results. To create advances in the characteristics of the suggested antenna, additionally, two cuts at the left and right corners are made in the antenna. Figure .1(c) shows the front view of the presented antenna with a partial ground to attain X and Ku-band characteristics and to bring nearer a standard return loss and to elevate the radiation e ciency of the antenna. The upgraded proportions of all the antenna parameters are declared in Figure 1.(a), 1.(b), and 1.(c). are referred to in the In terms of return loss, VSWR, gain, directivity, radiation e ciency, various patch con gurations put forwarded an antenna performance. We interpose the slots on the patch, so as to get an a rmative impact on outcomes. At various stages of design limitations, the illustrated layout model is exhibited and validated. Fig. 2(a), (b), and (c) represent the design limitations at various junctures. Above Fig. 2(a)   .0592, and -18.8137 respectively. Thus, the HFSS simulation result con rms that the return loss for the aimed multiband has been attained.

VSWR of designed antenna
VSWR is an essential requirement for the proper function of the antenna which implies the impedance matching between the source and the feed is optimum. It depicts the pattern and behavior of the antenna. In gure 5, the VSWR investigation has been shown. The VSWR obtained at the favored multiband is 1.11 at frequency 8.61 GHz, 0.39 at frequency12.31 GHz, and 1.33 at frequency15.62 GHz, 1.94 at frequency 18.19 GHz respectively. Thus, the proposed antenna is capable of providing the coveted VSWR outcomes.

Gain of the proposed Antenna
The power radiation in a given direction is revealed by the antenna gain. Figure 6 GHz respectively. We come to know from the directivity plot that the maximum amount of radiation intensity which is equivalent to 6.9104 dB is attained at a resonant frequency of 18.9447 GHz.

Radiation Pattern
The 3D radiation patterns for the elevation and azimuthal plane respectively of the proposed antenna is illustrated in gures above. The radiation pattern indicates the graphical portrayal of the radiation properties of the antenna as a function of space. The radiation pattern reports how an antenna causes energy radiation into space and reception. frequencies, return loss, and radiation e ciency, a fair comparative analysis is presented with the other considered antennas. The antenna performance lies in the X and ku frequency band.
The main focus of our designed antenna is to achieve "Size reduced", "multiband resonant frequencies" and hence can be taken up for multi commercial purposes. This antenna has been pro tably executed after numerous modeling and simulations by Ansoft HFSS 13.0 software to get the best solution of the parameters for overall performance. After getting good results from the simulated and measured parameters, the target was achieved.

Conclusions
In this research work, with the insertion of the slots, the effective patch size is marginally reduced but the performance of an antenna is signi cantly improved which causes multi-band resonant frequencies, very less return loss, and excellent radiation e ciency. The proposed compact rectangular microstrip patch antenna designed with double F Slots, four rectangular slots, side cuttings, and partial ground which covers multiple frequencies range between 8 GHz and 19 GHz which is found to be suitable for X and ku band applications. It is more e cient which achieves 96% e ciency. Due to the high radiation e ciency, ultra-wideband (UWB), reasonable gain, stable radiation pattern, less return loss ensures that the proposed antenna could be more suitable for radar, microwave imaging, satellite wireless communication applications and etc.