modified rectangular microstrip antenna

The geometries of conventional rectangular microstrip antenna (CRMSA), modified rectangular microstrip antenna (MRMSA) and Antenna-1 are shown in Fig. 1 to 3 respectively. These antennas are located in X-Y plane. As shown in Fig. 1 the CRMSA consists of rectangular geometry patch of length ‘L’ and width ‘W’ fed by using microstripline feed of length ‘L f ’ and width ‘W f ’. The quarter wave transformer of length ‘L t ’ and width ‘W t ’ is used between the patch and

Multiple transmit and multiple receive antennas has emerged as one of the most significant technical breakthroughs in next generation wireless communications. MIMO is the use of multiple antennas at both the transmitter and receiver to improve communication performance. MIMO technology has attracted attention in wireless communications, because it offers significant increases in data throughput and link range without requiring additional bandwidth or transmit power, higher spectral efficiency and reduced fading. Because of these properties, MIMO is an important part of modern wireless communication standards such as IEEE 802.11n (Wifi), IEEE 802.16e (WiMAX), 3GPP Long Term Evolution (LTE), 3GPP HSPA+, 4G and 5G systems to come. In today’s environment, technology demands antennas which can operate on different wireless bands and should have different features like low cost, minimal weight, low profile and are capable of maintaining high performance over a large spectrum of frequencies. In this paper microstrip patch antenna array are used, because of its attractive features of low profile, light weight, small size, low cost, easy fabrication [1]. Two modified rectangular shaped radiating patch element are arranged perpendicularly to each other on one side of the substrate, other side on which some rectangular defective ground structure[5-8] and their 2x1 MIMO implementation proposed which can be operated frequency range 7.14-7.42GHz, 7.6-8.2GHz, 8.2-8.6GHz, 9.8-10.2GHz frequencies for VSWR≤2, ECC less than 0.01; Mutual coupling is less than -10 dB. The antenna design is simulated using the CST microwave suit 2015. In section 2, the proposed antenna geometry is presented and in Section 3 the results are presented. The final conclusion of the paper is given in Section 4.

Now days the communication plays an excellent role in the worldwide society and almost all the communication systems are changing rapidly from wired to wireless. Wireless communication is much more flexible way of communication and antenna is the most important part of it. Recently the microstrip antenna is very useful due to its low cost, ease of Installation and integration with feed networks, low profile and small size [1-9]. On the move internet browsing, E banking, digital cable TV, etc and small handheld devices it is often require that the antenna to be achieve low profile good gain and wideband/multi-band characteristics. A number of approaches have been reported to obtain compact dual band micro-strip antenna such as loading of rectangular, circular and triangular patches by shorting pins, crossed slot and the use of a rectangular ring [2]. But the microstrip patch antenna has one serious drawback of narrow bandwidth as it limits the useful frequency band [2-3]. Several techniques have been used to enhance the bandwidth by interpolating surface modification into patch configuration. The most common techniques used to enhance the bandwidth and reduce the size of patch are multilayer techniques in which multiple layers of substrates are either stacked or arrange with airgap between them. In these kind of arrangements one layer is fed by coaxial Probe feeding techniques and others are been excited electromagnetically. In Airgap coupling generally we used three layers, two substrate’s layer and between them an airgap. In this arrangement lower layer is of same substrate on which we designed our patch. Over this layer we create an airgap and over this airgap we create another substrate layer on which we designed our patch. The substrate used to designed this antenna is FR4 substrate.

Several important observations from the results of the return loss are detailed as follows. First, the dimension of the rectangular patch basically corresponds to the quarter wavelength of the associated resonant frequency [18, 19]. In addition, the parameter results in not only the resonant frequency shifting but also the return loss level between the first and second resonant frequencies. For the second observation, the first resonance is barely changed for all different ground plane sizes as shown in Figures 3 When the ground plane is reduced in either length or width, the first resonant frequency is shifted slightly at around 3 GHz. These two observations imply that the resonant frequency is typically determined by the rectangular microstrip antenna size and slightly detuned by the size of the ground plane. The observation is that, as shown in Figure 2, the first resonant frequency is dependent on the size of the rectangular microstrip antenna as mentioned above while the second resonant frequency and the bandwidth obey the dimension of the cut area at the ground plane corners [20, 21]. The rectangular L- slot and diagonal cut are used to improve the impedance matching of the propose antenna to reduce the reflection of surface current, thus adjusting the parameters of slot cut to reduce return loss or enhance the bandwidth of UWB antenna.

A rectangular microstrip patch antenna with capacitive feeding is presented here. To overcome various problems in other feeding, capacitive feeding technique has used. The designed antenna consists of stacked arrangement of a rectangular radiating patch and a small feeding strip which is fed by coaxial feeding probe. Using capacitively fed rectangular patch antenna, the bandwidth achieved is 40%, for operating frequency of 2.427GHz. The effect of key design parameters like feeding strip length, feeding strip location, and feeding probe height are studied.

The antenna is simulated using the simulation tool HFSS 13.0. The antenna can be used in a cognitive radio application for sensing and communicating purposes. The reconfigurable functions are obtained using only one switch. By switching ON and OFF status of the switch, antenna can work in two cases for underlay mode applications. The proposed antenna can also be used as multiband or multimode antennas. As a result, they can well meet the WB cognitive radio communication requirement and effectively change the modes to prevent potential interference between secondary users and primary users.

Microstrip patch antennas have a radiating patch, dielectric substrate and ground. Selecting substrate is a key step in designing because a property of an antenna varies with a different substrate materials. As we know that the demand of microstrip antenna is increasing day by day because of their large number of advantages such as low cost, low volume, easy integration and light weight etc. These advantages make microstrip antenna applicable for various applications such as mobile, radar, satellite communication field, etc [1-3].

frequency the oscillation ceases. That why this frequency shows that the operating frequency of the antenna should be less than the resistive cut off frequency. And the self- resonance frequency is the frequency at which the imaginary part of the input impedance is zero that’s why this frequency is known as self-resonance frequency [5, 8]. The location of the tunnel diode is such that the device impedance is matched with input impedance of the microstrip. And the diode location y 0 is given as.

Recently, there are rapid developments in wireless communications, and in order to satisfy the IEEE 802.11 WLAN/WiMAX standards, the printed monopole antennas are required. These printed monopole antennas are very suitable to be integrated on the circuit board of a communication device, leading to the attractive features of occupying very small volume of the system and decreasing the fabrication cost of the final product. With the use of this kind of printed monopole antennas, a concealed antenna for the system can be obtained; that is, there are no protruded portions in appearance for the antenna [1]. For short- and long-range applications, many antenna designs suitable for wireless local area network (WLAN: 2.4–2.483, 5.15–5.35, and 5.725–5.85 GHz) and worldwide interoperability for microwave access (WiMAX: 2.5–2.69, 3.3–3.8, and 5.25– 5.85 GHz) operation have been studied [2-6]. The simplest way to implementing planar forms of the antenna is using the microstrip feeding technology. Microstrip antenna in its simplest form consists of a radiating patch on one side of a dielectric substrate and a ground plane on the other side of the substrate [3]. Recently several interesting designs of the slot antennas with diverse geometric configurations for the bandwidth enhancement and the size reduction functions have been widely studied[4]. Size reduction and bandwidth enhancement are becoming major design considerations for practical applications of micro strip antennas. For this reason, studies to achieve compact and broadband operations of micro strip antennas have greatly increase [5]. Defected Ground Structure is one of the methods which is used for this purpose. The defect in a ground is one of the unique techniques to reduce the antenna size. So design the antenna with the defected ground structure, the antenna size is reduced for a particular frequency as compared to the antenna size without the defect in the ground.

Microstrip antennas are also crucial in variety of applications as transmitters and or receivers in our modern wireless society. So far no literatures reported 2.45 GHz application of microstrip antenna in salt and sugar sensing. The 2.45 GHz microstrip antennas can be considered as a sensor in food or agricultural products, firstly introduced in this paper for substance determination in water. However, many methods [5-12] exist for the determination of moisture content and soluble solids content in agriculture products. However, these methods are complex and very tedious to be conducted and cause severe error during the measurement.

ABSTRACT: This paper presents the effect of pentagon slots on rectangular microstrip antenna. The proposed antennas operate for dual, triple and quad band as the pentagon slot is located at various quadrants of the rectangular patch without affecting the primary band. This antenna also gives the better gain of 5.99dB and exhibits broadside linearly polarized radiation characteristics. Simulated and experimental results are analyzed, presented and discussed.

this Paper presents the result for different dielectric constant values and the result is performed by thickness of 2.88mm and resonance frequency of 2GHz where 2.32 (Duroid) are gives the best result. In the recent years the development in communication systems requires the evelopment of low cost, minimal weight, low profile antennas that are capable of maintaining high performance over a wide spectrum of frequencies. This technological trend has focused much effort into the design of a Microstrip patch antenna. The proposed antenna design on different dielectric constant and analyzed result of all dielectric constant from 1 to 10, when the proposed antenna designs on Duroid substrate with dielectric constant 2.32. At 2GHz verified and tested result on MAT

ABSTRACT: This paper presents a waveguide fed circular patch microstrip antenna for 5GHz wireless applications. The proposed antenna describes a new feeding technique using rectangular waveguide. This antenna is fabricated over a double sided FR4 substrate of 1.6mm thickness with a dielectric constant of 4.3. The antenna analysis is carried out by matlab software. The return loss and radiation pattern of proposed antenna is explained. It is demonstrated that the proposed antenna can be used for 802.11a WLAN applications due to 5GHz resonant frequency.

and low profile antennas so use of these kind of antennas are more easy in portable and small communication de- vices where size is concerned . In this paper the analysis of T –slot rectangular microstrip patch antenna is presented. The antenna is designed for wide applications in C-band space communication and wireless LAN communication systems. The bandwidth of proposed antenna is 210 MHz and 87.1 MHz And Active VSWR of antenna is 1.316 and resonant frequencies are 7.09 GHz and 3.77 GHz . Antenna is simulated by HFSS software.

A Microstrip device literally means a sandwich of two parallel conducting layers separated by single thin dielectric substrate. The lower conductor is called ground plane & the upper conductor is a simple resonant circular/rectangular Patch. The metallic patch (usually Cu or Au) may take many geometrics viz. rectangular, circular, triangular, elliptical, helical, ring etc. The Microstrip patch antenna is commonly excited using a microstrip edge feed or a coaxial probe. The canonical forms of the microstrip antenna are the rectangular and circular patch MSAs. The rectangular patch antenna in is fed using a microstrip edge feed and the circular patch antenna is fed using a coaxial probe.

Figure1(a) shows the geometry of the proposed conventional MSA, where a low cost glass epoxy FR4 dielectric material with relative permittivity (εr) of 4.4 with thickness (h) of 1.6mm is chosen. The conventional MSA is designed for 6GHz with dimensions L and W radiating part, which is excited by simple 50 Ω microstrip feed having dimensions length Lf and width Wf using quarter wave length transformer of dimension length Lt and Wt for their impedance matching. The length Lg and Wg of the ground plane of the antenna is calculated by Lg=6h+L and Wg=6h+ W and all the dimensions are shown in table1.The photographic view of the MSA is as shown in Figure1 (b).

MSAs generally consist of a very thin (thickness, ) metallic strip or patch printed (photo-etched) on a small fraction of a wavelength ( , which represents the height of the substrate material above a ground plane, . The microstrip and the ground plane are separated by a dielectric surface, commonly called a substrate. The length of the rectangular patch is usual- ly . Different substrate materials have been employed for the design of the MSA, with their dielectric constant ( ) values ranging from range. Dielectric substrates for good antenna performance are thick materials with lower values since they have been found to provide better efficiency and larger bandwidth. Therefore, it’s essential for antenna design engineers to consid- er the choice of substrate very important. Although, thinner dielectric substrates with higher are more desirable in microwave circuits because they lead to smaller ele- ment size and they have relatively smaller bandwidths. The design cost is reduced in efficiency, and greater losses are experienced. In practical applications, MSAs are mostly used in microwave applications. Hence, a compromise has to be reached to achieve good performance [3].

1980; Richards et al., 1981; Carver and Mink, 1981; Deshpande and Bailey, 1982; Pozar, 1982; Gupta and Benalla, 1988; Richards, 1988; Abboud et al., 1988 ; James and Hall, 1989, Lo et al., 1989; Aksun et al., 1990; Bhartia et al., 1991; Hırasawa and Haneishi, 1992; Damiano and Papiernik, 1993; Zürcher and Gardiol, 1995; Pozar and Schaubert, 1995), have been developed for the determination of the input impedance of rectangular microstrip antenna with probe excitation fed from a coaxiall line. These methods have different levels of complexity, require vastly different computational efforts, and can generally be divided into two groups: simple analytical methods and rigorous numerical methods. Simple analytical methods offer both simplicity and physical insight. They yield results accurate enough for many engineering purposes. However, exact mathematical formulations in rigorous methods involve extensive numerical procedures, resulting in round-off errors, and may also need final experimental adjustments to the theoretical results. They are also time consuming and not easily included in a computer-aided design system, and provide little physical insight.

A novel metamaterial based microstrip patch antenna embedded with two square complementary split ring resonators (CSRR) for operating in C-band (4- 8GHz) is proposed. An effective microstrip patch antenna can be designed by etching two CSRRs in a conventional patch antenna. The proposed antenna operates at 5.4GHz. It is advantageous for designing a microstrip antenna with miniaturized size for satellite applications. At operating frequency, the antenna exhibits better performance. The CSRRs embedded on the patch antenna helps in miniaturization of the patch antenna. CST software is being used to simulate all the plotted geometry. Here VSWR, directivity, gain, axial ratio, radiation pattern of different designed antenna are evaluated. In future other different type of feed techniques can be utilize to evaluate the total performance of the antenna without ignoring the optimized parameters of it in the action. Exclusively and extensively focusing on the area of different design methods which principally intensify the efficiency and impedance bandwidth.

In the design of proposed antenna we make firstly design of a rectangular patch with calculated dimension of patch and ground plane and make design on the patch. Dimensional parameters of proposed antenna are list below table 2. Then we cut a slot on rectangular patch like a mirror image of c shape after this we measure the gain, return loss and all other parameters then we cut another slot by its corner of shape and again measure all parameters, finally we cut a slot from other edge corner and noted down all parameters. By operating this way the resonant peak shifted towards lower frequency side and as a result the bandwidth has been enhanced.