The bandwidth of the traditional rectangular patch antenna is about 0. Keywords bandwidth, dielectric constant, microstrip antennas, substrate thickness. Microstrip antenna has various applications because it have various advantages as to conventional antenna. To meet these requirements, a onelayer patch antenna was developed based on the ris metamaterial approach. For am radio at khz, the microstrip patch would be the size of a football field, utterly impractical. For high frequency designs we usually use high dielectric constant materials like roger etc. The dualband operation of a microstrip patch antenna on a duroid 5870 substrate for ku and kbands is presented. A microstrip patch antenna has the advantages of low. Not just for patch antenna, mostly we used fr4 substrate for low frequency designs because it is lowcost and easy available in the market. The most commonly employed microstrip antenna is a rectangular patch which looks like a truncated microstrip transmission line. The common arrangement of patch antenna can be made up of a radiator on front side of the substrate while a ground plane on the back side of patch antenna. But the biggest disadvantages is that it has very narrow bandwidth and low gain.
Here we discussed different dielectric substrate frequently used in microstrip patch antenna to enhance overall efficiency of antenna. Substrate is a base or container on which microstrip patch metallic sheet antenna is fabricated and it plays important role in microstrip antenna functioning. Next, the effect of cover layer on impedance matching, q factor hence bandwidth and frequency correction is discussed. In terms of its performance, the microstrip patch antennas can provide dual and circular polarizations and can be operated using two frequencies. By using complementary rhombus resonator crr, a smallsize and lowprofile microstrip patch antenna mpa with broad bandwidth has been proposed. If the ratio lw is close to unity, the radiation pattern will be symmetric but may not provide a resonable input impedance. Bandwidth improvement for compact microstrip patch. In this paper we are going to enhance gain and bandwidth of microstrip patch antenna. The radiating elements and the feed lines are usually photo etched on the dielectric substrate. What is the effect of a substrate in a microstrip antenna.
The basics of patch antennas, updated orban microwave. Such antennas are low weight, highly compact and efficient and are. In order to compare the different types of antennas, the physical dimensions of the antenna can be confronted to the bandwidth achieved. The most common type of microstrip antenna is the patch antenna. The qfactor of the antenna can be improved by considering a thick substrate, but that will lead to more power delivered to the surface waves, which results in unwanted power losses. Lowcost dielectric substrate for designing low profile. As shown in the schema below, high bandwidth cannot be reached with both small surface and small volume. Different substrates use in microstrip patch antennaa survey. The gain bandwidth product is a constant, therefore an effort has been made to improve the bandwidth of the patch antenna while ensuring desired radiation pattern. Inserting a proper feeding plays a good role in the bandwidth enhancement. Hence the substrate is important in antenna design which causes to miniaturization as well as broadband ing the antenna. A thicker substrate increases the gain to some extent, but may lead to undesired effects.
A thicker substrate is mechanically strong with improved impedance bandwidth and gain. Apr 01, 2017 the substrate between patch and ground plane plays important role in design it decides the bandwidth as well as size of the microstrip antenna. How to increase the bandwidth of my microstrip patch. The proposed antenna has been designed and fabricated on ceramicptfe composite material substrate of high dielectric constant value. Study on bandwidth enhancement techniques of microstrip antenna. The vswr, gain pattern and return loss performance are used for the analysis of the configuration. Effect of feed substrate thickness on the bandwidth and radiation. Anyone can help me out that how can i increase the bandwidth. The fabrication of the proposed antenna is performed with slots and a duroid 5870 dielectric substrate and is excited by a 50. The finite element method based, full wave electromagnetic simulator hfss is efficiently. This paper proposes a small sized, lowcost multiband monopole antenna which can cover the wimax bands and cband.
Lenghtheffective wavelength2under root of relative permitivity of substrate. A compact square loop multiband patch antenna design on high dielectric ceramic composite material was proposed. Some of them resort to the material side by using thicker or bi layered substrate 1,2 or reducing the dielectric constant 3. During the past years, numerous methods have been proposed to enhance the bandwidth of mpas, such as increasing the thickness of the substrate 8, 9, decreasing the substrate dielectric constant 10, 11, loading chip resistor, using parasitic patches in single layer and multilayers configuration 15, employing electromagnetic band gap structures 1619, and using backed edgefed cavity 20, 21.
The illustrated patch antenna provides bandwidth enhancement compared to antenna without slots of the same physical dimensions. The patch antennas gain is shown here as a function of frequency. Also, from fig3b,we find that, the microstrip patch has a very narrow bandwidth of 45. This paper proposes a small patch antenna on metamaterial substrate. As reported in 30, a power division network was employed in a monopole antenna, and a 10. Jun 03, 2015 in order to design a microstrip patch antenna at first the designer is to select the substrate material and its thickness. Bandwidth enhancement of microstrip patch antenna using metamaterials. Resonance frequency and bandwidth of rectangular microstrip. The patch antenna is made from polyethylene dielectric substrate and aluminum adhesive strip conductive layers. However, there is another issue of axial ratio bandwidth that needs to be concerned especially for a circularly polarized patch antenna.
Microstrip patch antennas, in their conventional form, are narrowband structures. There are various methods to increase the bandwidth of microstrip patch antennas. A single patch antenna provides a maximum directive gain of around 69 dbi. Microstripfed patches have very narrow bandwidths, almost invariably less than 5%. A dielectric substrate similar to that shown in fig. We report an improved cavity model called modified wolff. Why should fr4 substrate be mostly used in microstrip. The antenna consists of a triangular patch as the main radiator printed on an fr4 substrate with dielectric constant. Communication can be broadly defined as the transfer. Multilayer microstrip antenna use two microstrip patched with. Rectangular patch antennas are notoriously narrowband. The newly invented metamaterial antenna contributes the best return loss of more than 20. Even if you can achieve impedance bandwidth as large, pattern and gain bandwidth would be smaller.
Other features of this antenna include frequency agility, feedline flexibility, wide bandwidth, omnidirectional patterning and beam scanning. The substrate between patch and ground plane plays important role in design it decides the bandwidth as well as size of the microstrip antenna. The antenna generated omnidirectional radiation patterns with. An additional resonance is introduced by the crr to broaden the bandwidth. Antenna bandwidth is described on the basis of gain. Dualband operation of a microstrip patch antenna on a duroid. First of all, a thicker substrate with a low dielectric constant or a ferrite composition provides a wider bandwidth but. The microstrip patch antenna calculator determines the length l and width w of a rectangular microstrip patch antenna for a given resonant frequency or vice versa.
A compact monopole antenna with rectangular and triangular slots etched on the partial ground and the center of the rectangular patch achieves a wide usable fractional bandwidth of 148% in 29. The microstrip patch antenna dimensions are calculated. Microstrip patch antenna parameters and experimental setup simulation, fabrication and measurement 58 2. A microstrip fed rectangular patch antenna is designed to operate between 902 and 928 mhz uhf rfid frequencies. It is observed that as value of g increases the antenna impedance, bandwidth bw and antenna radiation efficiency. The above equation says that the microstrip antenna should have a length equal to one half of a wavelength within the dielectric substrate medium. What is the purpose of a substrate in a microstrip patch. Compact doublep slotted insetfed microstrip patch antenna. Microstrip patch antenna, radar, defense wireless communication, return loss, gain, bandwidth etc.
A singlelayer microstripfed patch antenna with capabilities of both bandwidth enhancement and harmonic suppression is proposed. While this model uses an inset feeding strategy that does not need any additional matching elements. But the biggest disadvantages is that they are narrow band antennas. Impact of substrate thickness on patch antenna performance. Axial ratio bandwidth of a circularly polarized microstrip. Figure 4 shows the overall radiation efficiency of the patch antenna, which ranges from 84% to 89% across the operating bandwidth. Bandwidth improvement of microstrip patch antenna using. The main component of the microstrip path antennas are substrate, patch, ground plane, line fed. Enhancing the bandwidth of a microstrip patch antenna using slots. Common microstrip antenna shapes are square, rectangular, circular and elliptical, but any continuous shape is possible. The frequency of operation of the patch antenna of figure 1 is determined by the length l. The effect of changing substrate material and thickness on. A patch antenna is a narrowband, widebeam antenna fabricated by etching the antenna element pattern in metal trace bonded to an insulating dielectric substrate, such as a printed circuit board, with a continuous metal layer bonded to the opposite side of the substrate which forms a ground plane. I have designed a microstrip patch antenna in hfss at 28 ghz, its bandwidth is almost 1.
So, if the designer has a clear conception about the effect of changing substrate material and its thickness on the performance of the antenna, it will be easier to design an antenna. The distance between the patch and the ground plane the substrate or dielectric height h determines the bandwidth. Secondly, the microstrip antenna was designed to operate at 100 mhz, but it is resonant at approximately 96 mhz. Study on bandwidth enhancement techniques of microstrip. Antennas using patches as constitutive elements in an array are also possible. Bandwidth enhancement in patch antenna by metamaterial. The center frequency will be approximately given by. The antenna was designed for xband application with a specific cutoff frequency at 11. Although the reported antenna achieved multiband, impedance bandwidth was low and substrate cost was high compared with epoxy resin fibre.
Bandwidth and efficiency of a microstrip antenna depends upon many factors for eg. The antenna has three doublering resonators drrs etched on the metal patch, and a partial ground plane so that the impedance matching characteristics of the antenna are much better. What are techniques to increase the bandwidth of microstrip. Various substrates like foam, duroid, benzocyclobutane, roger 4350, epoxy, fr4, duroid 6010 are in use to achieve better gain and bandwidth. The proposed antenna can be used in the cband wireless. The metamaterialinspired antenna employs simple structures since there is only one substrate layer and an intact patch applied in the antenna. Fig 6 design of single patch antenna in hfss simulation results the 2x2 patch array antenna is simulated using ansoft hfss. Gain and bandwidth enhancement techniques in microstrip patch. In this paper, the design frequency and the thickness of the substrate were kept constant, while different substrate materials were used in the design of an inset fed rectangular patch antenna in other to study the effect of these substrate materials on the gain and radiation pattern of the. A microstrip patch antenna is basically a very thin metallic patch placed above a ground plane. Either single or multiple feed lines are used to provide excitation to the antenna. Effects of using different substrates on the performance of an inset. Different dielectric materials affect the electrical characteristics of a patch antenna differently. If you wanted to make a microstrip antenna to receive fm radio at 100 mhz it would be on the order of 1 meter long which is a very large circuit for any type of substrate.
A broadband rectangular microstrip patch antenna for. The overall gain of the patch antenna can be increased by increasing the substrate thickness, but this will also impact the size of the antenna. May, 2012 the secondthird aspect is the analysis and design of two gapdirect coupled parasitic patch along radiating edge of main patch and in forthfifth aspect is the analysis and design of two layer of substrate on parasitic patch design. Pdf substrate height and dielectric constant dependent. How can i increase the bandwidth of a microstrip patch antenna. Often microstrip antennas are also referred to as patch antennas. Printed wideslot antenna design with bandwidth and gain. Bandwidth enhancement of microstrip patch antenna using. It is relatively easy to print an array of patches on a single large substrate using. It is good for expanding the operating bandwidth and enhancing the radiation gain. This paper presents a compact sized insetfed rectangular microstrip patch antenna embedded with doublep slots.
We can increase bandwidth by using very low dielectric substrate material such as air wich have er1 and by increasing thickness between patch and ground. The parameters evaluated were gain, beamwidth and return loss. Bandwidth enhancement of circular microstrip patch antenna. Microstrip patch antenna calculator electrical engineering. A patch antenna is shorted to the ground plane with thin wires, which is called monopolar wire patch antenna is proposed in 2. The impedance bandwidth and radiation characteristics of an aperturecoupled microstrip linefed patch antenna acmpa with a high permittivity. A compact microstripfed patch antenna with enhanced.
Bandwidth enhancement of microstrip patch antenna using parasitic patch configuration abstract. The frequency of operation for the patch antenna design has been selected as 2. The antenna patch is deposited on the underside of the substrate which acts as a protective cover. Antenna bandwidth is an important parameter of antenna over the range of frequencies fulfilled by the desired antenna characteristics. Feeding is extremely important with the patch antenna, and it contributes to bandwidth, crosspolarization levels, and ripple. Introduction with the wide spread development in wireless communication technology in recent years, the requirement of compact size, low profile and broad bandwidth antenna has augmented drastically. For good antenna performance, a thick dielectric substrate having a low dielectric constant is desirable for higher bandwidth, better. Effects of using different substrates on the performance of. The most attractive feature of the substrate is the ability of enhancing the bandwidth of a patch antenna. Besides these advantages it increases weight and introduces surface wave losses. Bandwidth enhancement for thin substrate uhf rfid patch antenna.
Microstrip patch antenna has been designed in order to rule out the conventional antenna as the patch antennas are used in most of the compact devices. For example by decreasing the qfactor of the patch and by increasing the substrate height and lowering the. A patch antenna is a narrowband, widebeam antenna fabricated by etching the antenna element pattern in metal trace bonded to an insulating dielectric substrate, such as a printed circuit board, with a continuous metal layer bonded to the opposite side. This paper presents an unconventional bandwidth enhancement technique for thin substrate uhf rfid linearly polarized patch antennas. Design techniques have been developed in order to achieve higher bandwidths, as will be demonstrated in this paper. The patch antenna s gain is shown here as a function of frequency. The dielectric constant plays an important role similar to that of the thickness of the substrate 5. Bandwidth enhancement for thin substrate uhf rfid patch. Resonance frequency and bandwidth of rectangular microstrip antenna on thick substrate. Parametric studies were conducted to illustrate the working principle of the proposed antenna. But patch antennas can also be formed with a collection of multiple patches on a dielectric substrate.
Microstrip patch antenna mpa is more capable than other antennas. Patch antenna is design with microstrip line inset feeding technique shown in fig. Here, we measure the antenna parameters by varying substrate thickness h from 0. Srr superstrate for gain and bandwidth enhancement of. This paper illustrates the design of a gap coupled modified square fractal microstrip patch antenna which has been designed to overcome this limitation. The percentage bandwidth of the rectangular patch microstrip antenna in terms of patch dimensions and substrates parameters is given as follows. Design approach a basic microstrip antenna msa is typically low power, low gain between 58 db and is fundamentally bandwidth limited to approximately 2 5% 1. The 10 db impedance bandwidth of the proposed antenna is 2. Bandwidth enhancement in patch antenna by metamaterial substrate.
Bandwidth enhancement in multipatch microstrip antenna array. Compared with the mpa without the crr, the bandwidth of the proposed antenna. Effect of height of the substrate and width of the patch. Improving bandwidth rectangular patch antenna using different. There are various shapes of patch antennas for example square, rectangular, circular, triangular, dipole, and elliptical. Improving bandwidth rectangular patch antenna using. But 27 ghz is too big of a bandwidth to cover with patch antenna. For example by decreasing the qfactor of the patch and by increasing the substrate height and lowering the dielectric constant the bandwidth of microstrip patch antennas can be increased. When air is used as the dielectric substrate, the length of the rectangular microstrip antenna is approximately onehalf of a freespace wavelength. Single microstrip antenna use low dielectric and thick substrate materials for wider bandwidth. The presence of arrays of microstrip elements provides greater directivity, higher.
A multilayer antenna substrate of low electrical loss, and the upper honeycomb, prevent surface wave propagation and increase the bandwidth. How can i improve the bandwidth of microstrip antenna without. Narrow bandwidth is a major constraint of microstrip antennas. Patch shape of singlefeed circularly polarized microstrip antenna the axial ratio 3db bandwidth of the circularly polarized microstrip antenna is much less than the impedance bandwidth of the linearly polarized microstrip antenna. The antenna is designed using high frequency structural simulator hfss software with return loss of almost40db and vswr 1 at 2. The substrate in microstrip antennas is principally needed for the mechanical support. Microstrip patch antenna bandwidth enhancement using amcebg. Impedance bandwidth is enhanced by intentional impedance mismatch at the edge of the patch.
The author has simulated micro strip patch antenna with prime focus of increasing bandwidth using various techniques of probe feed, parasitic patch around the main patch and two layer of substrate. Via application, the axial ratio 3db bandwidth the singlefeed circularly polarized microstrip antenna is limited at. Increasing microstrip patch antenna bandwidth by inserting. The simulation results show that embedding the slot and the slits in the triangular resonator increase the upper frequency bound resulting in a total bandwidth of 8. The microstrip antenna have various advantages like low cost, can be mounted on planar surface,light weight,support dual and triple band of frequency etc. Design and implementation of patch antenna 8 figure 2.