Additional benefits of patch antennas is that they are easily fabricated making them cost effective. The gain of the monopole antenna also decreases as the size of the ground plane decreases. How to increase gain of a microstrip patch antenna. I observed that as i increase the ground plane size, the gain increases at first and then decreases. Typical half wave patches have efficiencies well above 90%. Antenna design a conventional microstrip patch antenna is usually.
Design of a yagiuda antenna with gain and bandwidth enhancement for wifi and wimax applications vinay bankey 1 and n. For instance, many antenna types have very narrow bandwidths and cannot be used for wideband operation. This paper present a design of a frequency selective surface fss to improve gain and efficiency of a microstrip patch antenna operating in xband at 10 ghz. Slots to microstrip antenna to improve the performance like gain.
Increasing microstrip patch antenna bandwidth by inserting. These shorting pins tremendously perturb the field distribution beneath the patch due to their shunt inductive effect. The eshaped patch antenna has the highest bandwidth followed by ushaped patch antenna and hshaped patch antenna. To improve gain of patch antenna, 1 antenna vswr should be near to unity 2 substrate material must have lowest loss. It is a measure of how directional an antenna s radiation pattern is. The coupling is controlled by varying the distance between the slots 14. Omnidirectional pattern gain antennas to achieve a greater increase in this circular or omnidirectional pattern, we can stack multiple vertical dipole antennas above each other, as shown in figure 3. An amplifier type active microstrip antenna as a transmitting antenna with enhanced gain and bandwidth has also been implemented. L of the patch is to be calculated using the following equation 536.
Note that antenna gain isnt specified in db, but rather dbi or dbd db with respect to isotropic radiation or a dipole. An antenna that radiates equally in all directions would have effectively zero directionality, and the directivity of this type of antenna would be 1 or 0 db. Advantages of patch antennas the unique property of the microstrip patch antenna is its twodimensional structure. This is actually an advantage compared to antennas that have their gain. As shown in figure 2, the patch antenna consists of one ring slot at the center and smooth bevel and bevel at the edge of the patch antenna to enhance the. Also, if the antenna is lossy, the efficiency falls.
Gainenhanced patch antennas with loading of shorting pins. Pashan, pune411 021, india abstractthree hexagonal patch antennas are designed for circular. Bandwidth is enhanced by inserting slots on patch of microstrip patch antenna. Their low profile design, often square or rectangular, allows them to be mounted to flat surfaces. Techniques to increase gain and impedance bandwidth of a cross. Effects of ground plane size on antenna gain electrical. The proposed patch antenna is printed on a of fr4 substrate with thickness of 1.
Gain enhancement of a microstrip patch antenna using a reflecting. This design procedure is a set of simple design steps for the rectangular uslot mircostrip patch antenna on microwave substrates. How to improve the microsrip patch antenna performance or. A thicker substrate increases the gain to some extent, but may lead to undesired effects. The resonance method which involves the addition of a superstrate, increasing of gain by reduced parasitic element or a reduced surface wave 24. U slit loaded rectangular patch microstrip antenna. Microstrip patch antennas or simply patch antenna are increasingly useful because the antenna is printed directly onto a circuit board.
A gps patch antenna has high gain towards the zenith highest point in the sky, and gradually decreasing gain towards the horizon. Gain enhancement of the patch antenna using tsrr nri. Observe that the s11 of the antenna do not show any impedance bandwidth within the frequency range and that the current e patch antenna design might not be an optimized one. However they have major disadvantage of low gain and several methods has used to improve the gain of microstrip patch antenna. How can i improve the gain of a patch antenna and what is the. But despite of its bountiful advantages, patch antennas also experience some.
But the bandwidth would become smaller in this way. Many researchers are working to enhance the gain of the patch antennas using different designs, ideas, and materials 411. Introduction as a practical matter, the maximum directive gain directivity of an antenna depends upon. To improve the gain and the impedance bandwidth, optimize the antenna using the optimizer tab. A single patch antenna on fr4 can produce gain of 35dbi. Antenna gain is related to the antenna type, fr4 is lossy material therefore you can not expect large gain from fr4. Microstrip antennas, air substrate antenna, improved gain microstrip antenna, antenna radiation patterns, antenna gain. For an antenna with a directional pattern, less power will. Moreover, an approximately perfect matching is achieved. It should be noted that the presented stacked patch antenna in ref. Metamaterial enhances microstrip antenna gain microwaves. The proposed antennas may find applications in wireless local area network wlan. The fundamentals of patch antenna design and performance. Enhancing the bandwidth of a microstrip patch antenna.
An isotropic radiator will distribute this equally in all directions. Improving microwave antenna gain and bandwidth with phase. The aim of the project is to design a rectangular microstrip patch antenna with enhanced gain and bandwidth and study the effect of antenna dimensions length l, width w and substrate parameters relative dielectric constant. Also, if the antenna is lossy, the efficiency falls rapidly as the gain is increased over that of the uniformly illuminated aperture. This paper presents that, the detail steps of designing and simulating the rectangular patch antenna and rectangular patch antenna array in kuband. Anvesh kumar 2 1department of ece, vnit, nagpur, india as a lab engineer 2department of ece, vnit, nagpur, india as a research scholar abstract there are various patch antennas used for wifi and wimax applications.
The gain of this designed antenna is shown below in figure 14. If higher gain is desired, the antenna must necessarily be a narrowband device. These are about 2 db apart, so you really need to specify which one. The directivity of a patch can be estimated quite easily. The gain changes depending on the size of the ground plane. To increase antenna gain, you can change dielecdtric constant and thickness or, if you have no problems about accomodation or about antenna pattern, you can use a patch antenna array. I have designed a micro strip rectangular patch antenna.
One of the usually used methods to enhance the gain of mi. Based on the equivalence principle of huygens surface, we propose metasurface. Gain calculate of patch antenna in cst studio antenna,microstrip, patch antenna,coaxial cable,radio,microwave engineering,probe feed,cst,coaxial feed using cs. Many researchers are working to enhance the gain of the patch antennas. Impedance bandwidth and gain improvement for microstrip. The vswr is below 2 for the frequency range 4 to 8 ghz. The substrate material used for the proposed antennas is alumina 96%, with the dielectric constant of 9. The gain of an antenna refers to the ratio of its radiation power in a specific direction to its power in the isotropic direction 3. The array gain, dipolelike directivity and unidirectional characteristic are combined for approximately 8 to 9 dbi gain approx. High gain patch antenna using a frequency selective. Also making antenna arrays is a way of increasing the. The copper patch antenna displays a realized gain of. It consists of a flat rectangular sheet or patch of metal, mounted over a larger sheet of metal called a ground plane.
The designed antenna gain is greater than 6 dbi across 2640 ghz. The direction of the maximum gain of the antenna is above the patch ie, in the direction of theta, while minor lobes are on the. Often, the desired bandwidth is one of the determining parameters used to decide upon an antenna. The beamwidth is similar in both the xand yplanes, creating roughly a cone of radiation outward from the patch. Pdf gain and bandwidth enhancement techniques in microstrip. The gain of patch antennas can be increased by using mul tiple patches. The vswr is below 2 for the frequency range of 4 to 8 ghz. Effect of antenna size on gain, bandwidth, and efficiency. The basics of patch antennas, updated orban microwave. If it is a patch antenna, increasing the substrate height could lead to gain enhancement.
Gain enhancement of a microstrip patch antenna using a. To increase the gain the coupling is supplied by adding another slot in the ground plane as shown in fig1. Maximizing gain and improving impedance bandwidth of e. Here, we present a transparent metasurface for compensating the outofphase radiation from a microstrip patch antenna to improve its radiation gain and bandwidth. What are the best techniques to increase the gain antenna. The bandstop frequency selective surface fss designed at the operating frequency of the antenna is used.
The radiation pattern of this design is shown below in figure 15. How to increase antenna signal strength through design. A patch antenna is a type of radio antenna with a low profile, which can be mounted on a flat surface. Simulated and measured results are presented to validate the usefulness of the proposed antenna structure for uwb applications. Gain enhancement in microstrip patch antennas by replacing. There are four well known methods of increasing the gain of an antenna. As a flat antenna, arrays can have a large aperture, with corresponding high gain, but having low volume and weight. The antenna possesses a good return loss but a gain of 1. A new gain enhanced patch antenna with loading of shorting pins is proposed in this paper. This generally means using better materials, keeping the antenna clear of lossy media, and improving distribution and phase of antenna currents through better electrical design. Design of slotted ground hexagonal microstrip patch antenna and gain improve ment with fss screen nagendra kushwaha and raj kumar research scholar, department of electronics engg. This is the power dissipated in the radiation resistance of the radio antenna. In fact, the input impedance becomes frequency sensitive so rapidly that, for large antennas, no significant increase in gain over that of the uniformly illuminated aperture is possible.
Determine centre frequency, fo set center frequency as fo and the lower and upper frequency bounds of the bandwidth as flow and fhigh, respectively. I am trying to design a patch antenna, so i ran several fullwave simulations and increased the ground plane size each iteration, extracting the gain. The structure is modeled on photonic crystal substrate having a. The results of simulation for horizontally inserted slots are the same as that for microstrip patch antenna without slots. In this paper, we study the influence of the ebg superstrate on the performances of an aperture coupled rectangular microstrip patch antenna. Use of high permittivity superstrate loading technique gives an increase in antenna gain of about 10 dbi with a smaller radiating patch. This work is mainly focused on increasing the gain as well as reducing the size of. Developing a low cost high gain antenna can increase the wireless coverage. I have designed a microstrip rectangular patch antenna. Click here to go to our page on circular patch antennas new for september 2018. Gain calculate of patch antenna in cst patch antenna. Thus metamaterials is used to improve antenna radiated power with increased directivity.
Antenna gain can be only be increased two ways, by reducing losses or by increasing directivity. Deschamps in 1953, but didnt become practical until the 1970s when it was developed further by researchers such as robert e. Additionally, ive read a paper which claimed that the gain of the antenna changes. The following figure1 shows the gain pattern of the antenna in the farfield. Four metallic pins are symmetrically placed in the two diagonals of a square patch resonator to electrically short the patch and ground plane. Gain of the antenna is chiefly determined by the directionality of the antenna and the surface area. The distance between the patch and the ground plane the substrate or dielectric height h determines the bandwidth. Improving microstrip patch antenna directivity using ebg. The new fss structure is then applied as a superstrate to a conventional microstrip patch antenna. They are the original type of microstrip antenna described by howell in 1972. Metasurface, as a planar version of artificial metamaterial, provide an effective way to manipulate electromagnetic wave propagation. Moreover, the designed antenna has a smaller size of 27. Improving the gain of a patch antenna researchgate. Air as a substrate can give you maximum gain for a specific design since it has no dielectric loss.
Sometimes this requires the antenna occupy a larger spatial area. Gain enhancement of patch antenna integrated with metamaterial. How can i improve the gain of a patch antenna and what is. A patch antenna radiates power in certain directions and we say that the antenna has directivity usually expressed in dbi. Fss structure is configured as a superstrate for the microstrip patch antenna. Since you have a defined frequency, you need to make the antenna bigger to get more gain. If the antenna had a 100% radiation efficiency, all directivity would be converted to gain. Abstract a novel design of a new frequency selective surface nfss is presented, characterized and employed for the gain enhancement of a microstrip antenna operating at 5.
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