Design and performance evaluation of microstrip antenna. Microstrip patch antennas represent one family of compact antennas that offers the benefits of a conformal nature and the capability of ready integration with a communication systems printed circuitry. In this feed configuration the patch antenna appears in series with the feed because of slot coupling. Microstrip transmission line feed method is used to predict the skin effects on a patch antenna and their impact on antenna efficiency, resonance frequency and. Microstrip patch transmissionline model and inset feed the transmissionline model for a rectangular microstrip antenna has been extensively discussed in the literature 15. Microstrip antenna design using transmission line model. The input impedance of the antenna must be matched to the feed line by choosing the correct position for the feeding point. A rectangular patch with srr and parasitic patch antenna along with similar prototype microstrip line fed patch antennas are shown in fig. Microstrip antenna antenna radio transmission line. So, the microstrip line was compared to an antenna, and it wasnt until about 15 years later, when the microstrip patch antenna was proposed, which was based on precisely the same concept. The most two models of the rectangular patch antenna are transmission line model and the cavity model. The aperturecoupled patch element 4, 6 consists of two substrates, with a ground plane in between. Its physical characteristics include the microstrip width w, the microstrip thickness t, the substrate height d, and the relative permittivity constant. As shown in the geometry for a single aperturecoupled patch in figure 2, a microstrip feed line is printed on the bottom feed substrate, while the patch.
Antenna shape side of a dielectric substrate which other side has a radiating. Feed line calculations of microstrip antenna ijraset. In this video, im giving a little overview on how to use hfss to design a microstrip patch antenna. The radiating patch and the feed lines are usually photo etched on the dielectric substrate. Additional benefits of patch antennas is that they are easily fabricated making them cost effective. Simulation is done using the circuit model derived from the transmission line.
In order for the antenna to operate under the fundamental tm10 mode, the length of the patchmust be slightly less than. The most common type of microstrip antenna is the patch antenna. A broadband single feed circularly polarized patch antenna with wide beamwidth is presented. Design specifications of microstrip line feed patch antennasare given as. Microstrip line feeding method aperture coupled microstrip feed method proximity coupling method 1. The tradeoff between optical transparency and electrical conductivity will be evaluated for a range of visible regions. Their low profile design, often square or rectangular, allows them to be mounted to flat surfaces. The basic antenna element is composed of conducting material of dimension length. A microstrip patch antenna is very simple in the construction using a conventional microstrip fabrication technique1. For a standard rectangular patch antenna, each of the complex slot.
The following image shows a microstrip or patch antenna. Selecting best feeding technique of a rectangular patch. Construction of a microstrip antenna embodies a dielectric substrate with a groundplane conductor on one side and a thin, radiating conductor element on the opposite side fig. Coupling between the patch and the feedline is made through a slot or an aperture inthe ground plane.
Bandwidth enhancement ofrectangular microstrip patch. Consider the microstrip antenna shown in figure 1, fed by a microstrip transmission line. Fed with a halfwavelength transmission line previously, the patch antenna was fed at. Using the transmission line model, the antenna was designed to operate with a resonant frequency of 4. Design simulation and fabrication of microstrip patch antenna. Another method of feeding microstrip antennas is the aperture feed. Transmission line method is the easiest method as compared to the rest of the methods. The simplest way for estimating this is the transmission line model for the patch antenna.
Microstrip patch antennas radiate primarily because of the fringing fields. The proposed rectangular microstrip patch antenna having dimension 40. Representation of microstrip antenna using transmission line model. The patch is coupled to four asymmetric cross slots via a microstrip ring with eight matching segments underneath the ground plane, traversing through the arms of the cross slots in a serial manner. Microstrip antennas generally prefer to printed antennas used for narrowband range at ultrahigh frequencies and microwave communication.
Name is the property name and value is the corresponding value. Microstrip line feed is one of the easier methods to fabricate as it is a just conducting strip connecting to the patch and therefore can be consider as extension of patch. Antennas using patches as constitutive elements in an array are also possible. This paper presents the transmission line model for analyzing the microstrip line inset fed patch antenna and also presents a curve fit formula for locating the exact inset length to obtain 50 i input impedance. Analysis on the basis of transmission line model was selected because it is the simplest of all models in the matter of complexity of analysis. Transmission line model the rectangular patch the tl model is the simplest of all, representing the rectangular patch as a parallelplate transmission line connecting two radiating slots apertures, each of width w and height h. This design approach helps analyzer microstrip insetfed patch antennas and. This method represents the rectangular microstrip antenna as an array of two radiating slots, separated by a low impedance transmission line of certain length.
It concerns a transmissionline model which features the following three major. Aperture feeds another method of feeding microstrip antennas is the aperture feed. Fang microstrip antenna design handbook garg et al title says it all, but a few inaccuracies have been found antenna theory constantine balanis used for antennas i elen 715. Because the antenna must be fed with the microstrip, the connection to a point inside the metal patch. To determine the width w, the microstrip patch antenna calculator was used to provide an initial. Microstrip patch antennas or simply patch antenna are increasingly useful because the antenna is printed directly onto a circuit board. The inner conductor of the probe line is connected to patch lower surface through slot in the ground plane and substrate material 6. This paper presents a double layered slotted square patch microstrip patch antenna with a single probe feeding to the lower patch. Pdf modelling and simulation of a rectangular microstrip. Transmission line model of dual patch aperture coupled. It is simple to model and easy to match by controlling the inset position. The transmission line model is the simplest of all and it gives good physical insight. A wave port extends the trace in negative x direction to the left of the actual port position. Microstrip square patch antenna using cst by shamsur.
The printed array to be considered is one using aperturecoupled bowtie microstrip patches. The radiation pattern of microstrip or patch antenna is. Microstrip patch antenna with coaxial feeding using cst simulator. This paper we use here the transmission line model for designing hexagonal shape having ground cut microstrip.
Therefore, inset fed patch antenna with a microstrip line feed was considered as a base structure. Hfss design of rectangular patch antenna using microstrip line feedingedge feeding. Microstrip antenna design using transmission line model in. In the modern days the development in communication systems engineering requires the development of low profile antennas that are capable of maintaining high performance over a wide spectrum of frequencies. A novel microsrip antenna is presented here, which is formed by using two aperture coupled rectangular patches fed back to back by a single feed line placed in. Patch antennas and microstrip lines 51 amount of power that is transferred to the load or the amount of power reflected back. Ijcsi international journal of computer science issues. Design formula for inset fed microstrip patch antenna. When the antenna is excited, the waves generated within the dielectric undergo reflections and the energyis radiated from the edges of the metal patch,which is very low. A microstrip transmission line is shown in crosssection in the following figure. Microstrip line feeding microstrip line feed is one of the easier methods to fabricate as it is a just conducting strip connecting to the patch and therefore can be consider as extension of patch.
Corporatefeed multilayer bowtie antenna array design. And a coupling slice instead of a resistive load is used as matching load of the microstrip ring for. The coaxial feed line is used with substrate permittivity. The key factors in the design of microstrip patch antennas having operating. Transmissionline analysis of patch antennas in this model, a rectangular microstrip antenna patch, of figure 3, is viewed as a resonant section of a microstrip transmission line, since it has a physical structure derived from microstrip transmission. Analysis of microstrip line fed patch antenna for wireless. Transmission line model an overview sciencedirect topics. Transmission line model of dual patch aperture coupled microstrip. This technological trend has focused much effort on the basic concepts. Modeling of different feeding techniques for a microstrip patch. In this technique, the feed circuitry transmission line is shielded from the antenna by a conducting plane with a hole aperture to transmit energy to the antenna, as shown in figure 5. In the case of a microstriplinefed antenna, where the source and the transmission line characteristic impedance or the transmission line and the antenna edge impedance do not match, waves are reflected. The patch is of length l, width w, and sitting on top of a substrate some dielectric circuit board of thickness h with permittivity. Patch antenna design using transmission line model raymaps.
Accurate transmissionline model for the rectangular microstrip antenna article pdf available in microwaves, antennas and propagation, iee proceedings h 16. Antenna design the dimension of the antenna can be estimated by the transmission line model. Properties not specified retain their default values. The discretised model of such a scheme is shown in figure 8 b. Pdf accurate transmissionline model for the rectangular. 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. Typical radiation pattern of microstrip antenna the patch is generally made up of a conducting material such as copper or gold and can take any possible shape like rectangular, circular, triangular, elliptical or some other common shape. By using a straightforward transmissionline model, it is possible to accurately model and analyze microstripline insetfed patch antenna designs. The preferred models for the analysis of microstrip patch antennas3 are the transmission line model, cavity model, and full wave model which include primarily integral equationsmoment method.
Optical microstrip patch antennas design and analysis. Method of analysis transmission line model represents the microstrip antenna by two slots of width w and height h. We design a patch antenna with required dimensions and implement that model or simulated in hfss. According to the transmission line model, the length l and width w of the patch are calculated as although the design of the patch is quite simple, the design of the feeding mechanism is not that straightforward. The feed mechanism plays an important role in the design of microstrip patch. The patch antenna, microstrip transmission line and ground plane are made of high conductivity metal typically copper. The nonresonant slot is represented as an inductor in series wi th the rlc network representing the patch resonator. The transmissionline model agrees to the cos4 impedance variation for insetfed microstrip antennas with an addition of a corrective extended feed length upto the inner radiating edge. This model is used to perform parametric studies of the patch for various values of r 2 r. Accuracy of the formula is compared with the results obtained from the em simulator.
The two patches on the both sides of the microstrip feed line are acting as parallel loads. Hfss tutorial 1 microstrip patch antenna with coaxial feeding. The microstrip patch antenna model used for the numerical simulation in ansoft hfss is shown in fig. Two slots, each having a complex admittance, are placed at a distance of about. The model no longer gives the exact dimensions after introducing the defects in the ground. You can specify several namevalue pair arguments in any order as name1, value1. The coupling aperture is usually centered under the aperturecoupled feedpatch, leading to lower cross. A simple modified transmission line model for inset fed antenna.
446 1035 202 1306 343 1095 6 1146 931 254 388 277 275 897 790 292 900 838 426 813 1321 1520 1124 289 1170 646 390 1149 371 1501 518 86 802 952 430 1245 1399 634 982