Microstrip patch antenna design calculator 1 mosin i memon and 2 prof. The current at the end of the patch is zero and the current is maximum at the center of the halfwave patch. When feed, a standing wave will occur as shown in fig. 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. Fringing effect of microstrip antenna in antenna and wave. Higher the substrate, the greater is the fringing field. Design and analysis of microstrip patch antennas using. Design of an sband rectangular microstrip patch antenna.
An optimization procedure for a probefed rectangular microstrip patch radiator cad. But illustrates sizes and importance of good antenna design why microstrip antennas. The antenna consists of a single printed circuit board with an rf connector and perhaps an absorptive load. This study will help for authors and researchers to get a fair idea of which substrate should be given preference and why to fabricate microstrip patch antenna. This fringing field will radiate and create a radiation pattern that is determined by multiple design variables. The fringing fields along the edges can be explained and modeled as equivalent capacitance and radiation resistance of the transmission line as shown in fig. Microstrip patch antennas radiate primarily because of the fringing fields between the patch edge and the ground plane. Due to fringing field the electrical length of patch is always larger than its physical length. This radiation pattern shows that the antenna radiates more power in a certain direction than another direction. May 04, 2018 in this video, i have explained fringing effect of microstrip antenna by following outlines.
Deore masters thesis electrotechnology publish your bachelors or masters thesis, dissertation, term paper or essay. Design analysis of microstrip patch antenna in xband. The patch antenna is a good place to start for antenna fundamentals with more coming. The fringing fields can behave like as radiating slots and electrically the patch of the microstrip antenna. Note that since the current at the end of the patch is zero open circuit end, the current is maximum at the center of the halfwave patch and theoretically zero at the beginning of the patch. Design and fabrication of microstrip patch antenna on. The rectangular patch is one of the two most popular microstrip antenna types in wireless design the other being the circular patch.
The electric field radiates along the z axis, whereas the magnetic field is present in the x, y plane. At the start of the patch antenna a half wavelength away, the voltage must be at minimum v volts. Fringing fields are taken into account by extending the length of the patch antenna a and the width of the radiator b outwards using the design formulas of the microstrip lines. The fringing fields around the periphery are taken care of by extending the patch. The effects of fringing fields on the capacitance of a circular microstrip disk are studied with the dual integral equation formalism for practical microstrip circuits when the substrate thickness. These field extensions are known as fringing fields. An early model of the microstrip antenna is a section of microstrip transmission line with equivalent loads on either end to represent the radiation loss. Fringing fields at the border of the patch are not. The patch s radiation at the fringing fields results in a farfield radiation pattern. A microstrip patch antenna comprises of a patch element, which is a radiating material on one side of a dielectric substrate and a ground plane on the other side of it.
Er fixed by substrate 7 examples of patch antenna structures hplane pattern perpendicular to patch. Also, to add to the above answer, the radiation mechanism in patch antenna is due to the fringing fields. The pattern of a rectangular patch antenna is rather broad with a maximum direction normal to the plane of the antenna. Keywords fringing field, microstrip antenna, effective dielectric constant and. The permittivity should be low for large bandwidth but high to make the patch antenna smaller. A practical guide to the design of microstrip antenna arrays. The method is capable of accurately predicting currents, impedance and resonant frequency for any arbitrary surface patch antenna. One is for a normal patch antenna in which the varactor diode is connected across the patch and the ground plane. Nov 25, 2016 in microstrip antenna, it is the fringing fields that are responsible for the radiation. For good antenna performance, a thick dielectric substrate having a. A novel ellipticallyslotted patch antennabased biosensor. For good antenna performance, a thick dielectric substrate having a low dielectric constant is desirable since this provides better efficiency, larger bandwidth and better. Designing for designing of a microstrip patch antenna, we have to select the resonant frequency and a dielectric medium for which antenna is to be designed. Hence, the fringing efields on the edge of the microstrip antenna add up in phase and produce the radiation of the microstrip antenna.
The fringing fields along the width can be modeled as radiating slots increasing electrical length of patch than physical length 6. Hence, when designing a patch antenna it is typically trimmed by 24% to achieve resonance at the desired frequency. The designed antenna is emulated and analyzed by ie3d software. The microstrip patch antenna consist of a radiating patch on one side of the dielectric substrate which has a ground plane on the other side. The fringing fields around the antenna can help explain why the microstrip antenna radiates. Enhancing patch antennas performance using micromachining and ebg technologies dipto dey, sridhar kallapudi and rakhesh singh kshetrimayum.
In antenna design, it is common to select a topology and then lookup the design equations for that antenna. Microstrip patch antennas radiate primarily because of the fringing fields between the patch edge and the. The return loss and the various gain plots have been studied along with the radiation patterns. This causes radiation at the two edges of the antenna, as shown by the fringing fields in the diagram. Decreasing the permittivity also increases the antennas bandwidth. Effective dielectric constant of microstrip antenna 5. Consists of a metallic strip placed above a ground plane fringing electric fields from the two edges of the patch add to cause radiation. For good antenna performance, a thick dielectric substrate having a low dielectric constant jun, 2019 microstrip patch antennas radiate primarily because of the fringing fields between the patch edge and the ground place. This paper will investigate and discuss the design of microstrip patch antennas, using the theoretical method developed by abdalhameed and excell 1996. Jan 24, 2012 this shift is due to fringing fields around the antenna, which makes the patch seem longer. Shows a typical geometry of an equilateral triangular patch antenna with. Microstrip patch antenna design santa clara university. The basics of patch antennas, updated orban microwave.
Microstrip antenna an overview sciencedirect topics. It is the fringing fields that are responsible for the radiation. This tm notation often leads to confusion and here is an attempt to explain that. Fringing field with partial ground plane the antenna could be imagined as an impedance transformer, transforming the impedance of a microstrip line 50. In a patch antenna the surface conductor element does not form the radiating element, as in other antennas dipole, monopole, etc. Fringing field, microstrip antenna, effective dielectric constant and resonance. Fringing field is a function of effective dielectric constant. Design parameters and tradeoffs are presented for microstrip antennas. This had been the one of the main drawback of microstrip antennas. Fringing fields article about fringing fields by the free. It is because of these fringing fields that the patch looks electrically greater than its physical dimension. Fringing fields help in radiation and give more directive radiation pattern but.
The desired radiation efficiency, directivity, beam width and gain can be achieved by selecting proper design parameters and substrate material of the patch antenna. As discussed earlier, the design issues include antenna di. In this part of the workshop you will design a microstrip patch antenna. Design and radiation characterization of rectangular. Design parameters of rectangular microstrip patch antenna 4. Microstrip patch antennas come in conformable shapes like square, rectangle, elliptical, circular etc. The most common type of microstrip antenna is the patch antenna.
The electric field does not stop abruptly near the patch s edges like it would in a cavity. Curvature has a great effect on fringing field of a microstrip antenna and. The general dimensions are 2, however due to the specific dynamics of the antenna and the fringing fields, the exact dimensions require more careful calculations. In a patch antenna, most of the propagation is above the ground plane and can have high directional gain. Design smart antenna by microstrip patch antenna array. The basic structure of the microstrip patch antenna design is shown in fig.
This is one of the tradeoffs in patch antenna design. Design and performance analysis of microstrip patch. Design of a rectangular microstrip patch antenna using inset. Antennas using patches as constitutive elements in an array are also possible. Design of a dual patch triangular microstrip antenna. Hi, i was recently tasked to come up with a circuit diagram on how i would connect varactor diodes to my patch antenna so that i can tune the antenna electronically. The voltage is maximum fig 2 electric field lines to design the patch antenna, following things has to be determined reff effective dielectric constant. Some popular analytic modeling techniques for patch antennas are based on this leakycavity concept and the fundamental mode. Though, fringing fields effects on the performance of antenna and its resonant frequency have been presented before, effects of curvature on fringing field have not been reported before. Consider the side view of a patch antenna, shown in figure 4.
The radiated fields can be obtained by treating the antenna as an aperture. I have been working really hard on micro strip patch antenna design using hfss, and i do understand fringing effect in patch antenna but my question is how does the fringing effect will affect the. However, the electrical length is larger than the physical length of the radiating side due to the fringing fields. This shift is due to fringing fields around the antenna, which makes the patch seem longer. Generally, patch antenna has a shape of rectangle, and it can be feed with copper cable or microstrip line in our case. Structure of a microstrip patch antenna microstrip patch antennas radiate primarily because of the fringing fields between the patch edge and the ground plane. The patch antenna operates based upon the effects of a fringing electric field that is generated between the conducting patch and the ground plane. The design of a microstrip antenna begins by deciding used for the antenna so the size of the patch. In the drawing above, blue area is the substrate and brown area represents the top conducting layer which is half of the antenna. Radiation occurs mostly due to the fringing field between the patch and ground. Some popular analytic modeling techniques for patch antennas are based on this leakycavity concept and the fundamental mode of a rectangular patch is often denoted using cavity theory like the tm10 mode. Consider the side view of a patch antenna, shown in figure below. International conference on recent trends in engineering. L at each edge resulting from the fringing of fields.
Note that since the current at the end of the patch is zero open circuit end, the c. Let us first consider the rectangular microstrip shown in figure 5. Zhelev introduced a design of a small conformal microstrip gps patch antenna 14. The second approach was a more conventional patch antenna array beamsteering concept, whereby rf mems phase shifters, fed via a wilkinson power divider, were used for configuring the phase distribution of the signals of the antenna array. A collection of design formulas for circular and rectangular microstrip antennas excited in the lowest resonance mode are presented. Keywords dielectric substrate, microstrip patch antenna, triangular patch, xband, radiation characteristics. In this paper, initially we focus on the design and performance issues of microstrip antennas. What is fringing effect in microstrip patch antenna.
The patchs radiation at the fringing fields results in a certain farfield radiation pattern. Fringing fields represent extensions of the elements and have been considered when resonance dimensions are determined. These features of microstrip antennas make them suitable for various applications like, vehicle based satellite link. There are numerous substrates that can be used for the design of microstrip antennas. Design and performance analysis of microstrip patch antenna. How does the fringing effect in a patch antenna affect. Fringing fields are a part of the electric field lines that are partly in the substrate dielectric and partly in the air figure 2. Design of a rectangular microstrip patch antenna using. I have been working really hard on micro strip patch antenna design using hfss. Design of equilateral triangular microstrip patch antenna with coaxial feeding technique abstractthis paper presents design of equilateral triangular microstrip patch antenna with operating frequency at 2. Design of the patch we will follow a design approach such as the one described in 1.
How does the fringing effect in a patch antenna affect the. Design and implementation of rectangular patch antenna for triband operation prashant s. In this video, i have explained fringing effect of microstrip antenna by following outlines. This article introduces some of the basic concepts of patch antennas. The geometrical structure and configuration with detailed design parameters of the proposed patch antenna are shown in figure 1. Patch antenna design of a dual patch triangular microstrip antenna dual patches offer wider bandwidth for wireless applications in the 2. Apr 22, 2017 it is the fringing fields that are responsible for the radiation. Microstrip patch antennae radiate primarily because of the fringing fields between the patch edge and the ground plane.
The resonant length of the antenna is slightly shorter because of the extended electric fringing fields which increase the electrical length of the antenna slightly. This shift is due to fringing fields around the antenna. As an example, the size must increase to have it work at lower frequencies. Design of microstrip patch antenna elements nasaads. The amount of the fringing field is a function of the dimensions of the patch and the height of the substrate. The elements are modeled as cylindrical resonators with equivalent magnetic currents around the perimeters. Barnes cranfield college of aeronautics, cranfield university t his paper investigates the design, measurement and characteristics. The microstrip patch antennas are associated with several advantages of being low profile, versatile, conformal and lowcost devices. Microstrip patch antenna parameters and experimental setup simulation, fabrication and measurement 56 chapter 2. The design and simulation of patch antennas is widely used in mobile cellular phones today, and our emphasis in this work is on optimization of a 2.
The fringing fields near the surface of the espa are responsible for its radiation. For good antenna performance, a thick dielectric substratehaving a low dielectric constant is desirable since this provides better efficiency, larger bandwidth and better radiation 8. In microstrip antenna, it is the fringing fields that are responsible for the radiation. Lowcost dielectric substrate for designing low profile. The fringing field and resonance frequency of cylindrical microstrip. The equivalent magnetic surface currents m s are also shown. Equilateral triangular microstrip antenna a new design. The patch s radiation at the fringing fields results in a far field radiation pattern. Consider a square patch antenna fed at the end as before in figure 1a.
Side view of patch antenna with e fields shown underneath. Hence, a wider patch provides a wider dimension from which fringing can occur and hence is more suitable as a radiator than a narrower one which is used more as a transmission structure. Nov 23, 2015 the fringing fields around the antenna can help explain why the microstrip antenna radiates. The wider the patch becomes the lower the input impedance is. Rectangular patch antennas are notoriously narrowband. The microstrip patch antenna emanate because of the collection of opposite charges forming fringing fields between the patch edge and the ground plane. Design analysis of microstrip patch antenna in xband sabyasachi guha1, anil kumar dubey2, reena rathee3. The design and analysis methods of a patch antenna have been discussed. Hence, the fringinge fields on the edge of the microstrip antenna add up in phase and produce the radiation of the microstrip antenna. Performance analysis of a microstrip printed antenna conformed on. Microstrip antenna or patch antenna basics in antenna and wave propagation by. Design of a rectangular microstrip patch antenna at 1ghz. The radiation increases with frequency increase and using thicker substrates with lower permittivity, and originates.
The fringing must be taken into account because it influences the resonant frequency of the antennas. The permittivity of the substrate controls the fringing fields lower permittivities have wider fringes and therefore better radiation. Because of the fringing effects, electrically the patch of the microstrip antenna looks greater. The patch antenna element developed for the phased array sar pharus operating at 5. New procedure for design of microstrip patch antennas using.
Secondly, the microstrip antenna was designed to operate at 100 mhz, but it is resonant at approximately 96 mhz. Tutorial a practical guide to the design of microstrip antenna arrays roger hill philips research laboratories surrey, england a microstrip antenna array is one of the simplest forms of antennas available. Design and performance issues of microstrip antennas. A patch antenna is an antenna having narrow bandwidth and widebeam of radiation fabricated by photo etching technique on the dielectric substrate 2. L feed w ms e s patch y x figure 2 fringing electric fields that are responsible for radiation. A microstrip patch antenna is a radiating patch on one side of a dielectric substrate, which has a ground plane on the underside.
The efficiency is also increased with a lower value for the permittivity. Due to the effect of fringing, a microstrip patch antenna would look electrically wider compared to its physical dimensions. These field extensions are known as fringing fields and cause the patch to radiate. Pdf effect of fringing fields on the capacitance of. Consider the side view of a patch antenna, shown in figure. The fringing field has an important effect on the accurate theoretical modeling and performance analysis of microstrip patch antennas. Design simplicity and input impedance adjustment through feed point positioning. The polarization can be either circular or linear depending on the design of the patch. The first decision to be made in design of the patch antenna is to set the resonant or operating frequency f r for the antenna.
The 2nd one is a small patch antenna where the patch is shorted to the ground plane. Design of probe feed microstrip patch antenna in s band. For good antenna performance, a thick dielectric substrate having a low dielectric constant patch antenna design calculator 1 mosin i memon and 2 prof. The em waves fringe off the top patch into the substrate, reflecting off the ground plane and radiates out into the air. The general design principle is to trim the patch antenna by typically 24 % to obtain resonance at the desired centredesign frequency. In second case you short to ground the fringing fields from the edge of the patch element. If this inhomogeneous medium air and the dielectric is replaced with a homogeneous one, then all properties of the line or patch remain unchanged 3. In order to achieve good antenna performance, a thick dielectric substrate having a low dielectric constant is desirable as this provides better efficiency, larger bandwidth and better radiation. Design and implementation of rectangular patch antenna for.
349 1387 435 657 921 1220 1039 1587 147 899 1107 5 556 1263 1195 679 407 1148 1152 1232 1462 767 1296 25 1306 1492 1049 1150 525 1232 533 1454