Whats the difference between a dipole and a ground plane. Effect of slots in ground plane and patch on microstrip antenna. Pdf effect of slots in ground plane and patch on microstrip. A ground plane antenna is essentially one half of a dipole mounted vertically. Coaxialfed rectangular patch antenna lumerical support. The simulation results show that the gain of a circular patch antenna varies with the ground plane size. In general, the ground plane size of the patch antenna should be 23 times the patch size, so as to maintain a good front and rear ratio.
The gain and hpbw varied periodically with increasing ground plane. As this antenna can only radiate above the ground plane, a monopole antenna will have a gain of 3 db over an equivalent dipole. My understanding is that when building or installing an antenna designed to operate over a ground plane e. The distance between the patch and the ground plane the substrate or dielectric height h determines the bandwidth. Patch antenna ground plane effect on radiation pattern. Research student, department of applied electronics, gulbarga university, gulbarga, karnataka, india. Theory and experiment on microstrip antennas, ieee transactions on.
With dipoles, one half of the antenna is your ground. The antenna s feed is a through hole and reaches the bottom of board, where it meets a 50 ohm transmission line. Ground mounted antennas are often very easy and convenient to use. The image is a tool for understanding the earths effect on patterns. Its not feasible to center the antenna in the devices i worked on, so wed kind of shove the antenna in the corner of the pcb. In this paper, the geometrical theory of diffraction gtd r. What is fringing effect in microstrip patch antenna. Effect of rf antenna ground on radiation efficiency. In this example, fdtd is used to simulate a coaxialfed rectangular patch antenna mounted over an infinite pec ground plane, in which the antenna s return loss, directivity, and farfield patterns are found with the help of the directivity analysis group. The distance between the patch and the ground plane the. The term monopole is also used to describe this antenna. This indicates the size reduction of slotted patch antenna is more than slotted ground plane patch.
Rf ground and ground planes ham radio q and a episode 4. The computing time for a patch antenna with infinite ground plane using image theory is much shorter than that for a finite ground plane. The characteristics studied include return loss, gain, halfpower beamwidth hpbw, and radiation pattern. The fundamentals of patch antenna design and performance. The gain for the ground plane is very nearly constant and equal to an isotropic antenna at low heights and real ground conditions. Next, we apply the previous results to the case of a circularly polarized antenna, in order to optimize the ellipticity ratio. Effect of partial ground plane removal on the radiation. The antenna performance can be positive or negative. Patch antenna ground plane electrical engineering stack. Usually, a copper is used as a ground plane with thickness of 35 micron. Effect of ground plane size on a rectangular microstrip. Consider the microstrip antenna shown in figure 1, fed by a microstrip transmission line. The proposed lowcost, compactsize circular patch antenna on 3 cm 5.
Here is an example of an artificial ground plane added by someone to an 8 dbi 2. The finite ground plane effect on microstrip antenna radiation pattern. In antenna theory, a ground plane is a conducting surface large in comparison to the wavelength, such as the earth, which is connected to the. He said it is 12 inch behind the patch mounted with insulated plastic. The effect of the partial ground plane removal in different configurations on the radiation characteristics of a msa are investigated numerically. As the name indicates the antenna ground plane acts as a simulated ground. Because the impedance changes, the antenna will no longer be in the sweet spot the 50 spot, meaning that it will suffer impedance mismatch loss. As we know, there exists a current loop between the patch and ground plane when the.
While they have less reduction of rearward radiation than a larger design, they. The effects of varying the size of the ground plane of a rectangular microstrip antenna, which can excite te modes, are investigated in this paper. Ground plane monopole and marconi antennas are one quarter wavelength high. The ground plane 1 start with a vertical dipole in freespace cut off one half of the dipole replace the missing half with a ground plane or counterpoise omnidirectional if oriented vertically also called a monopole 20. What is the optmized size for a ground plane for micro. Wu 11 reported an analysis of microstrip antennas with. Study the ground plane effect of a multiband antenna for. However when it is not possible to ground mount an antenna because of ground conditions or it is necessary to elevate the antenna, another solution is to use a ground plane. The magnetic conducting patch and ground planes replace the electric conducting patch and ground plane. Ground plane gain equivalent to 2 dipole 3element yagi may have up to 5 dbd gain 20.
In electrical engineering, a ground plane is an electrically conductive surface, usually connected to electrical ground. At one end a rf source is connected and other end is. As the name indicates the antenna ground plane acts as a. In this view, we retain the concept that ground is an integral part of the antenna and an ungrounded vertical must have some structure that replaces the real ground. As the latter is the actual practical structure, it would be of advantage to find a cad formula to account for the impedance perturbation from an infinite ground plane to a small finite ground plane. The ground plane is a conductor and metals reflect electromagnetic radiation. May 04, 2018 in this video, i have explained microstrip antenna or patch antenna by following outlines. 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 monopole antenna fields below the ground plane in figure 1a are zero. Effect of ground plane for enhancing the bandwidth and virtual size reduction of modified rectangular microstrip antenna. This paper presents the effect of the slots in ground plane and patch on resonant frequency, impedance bandwidth, gain and side lobe. Is a ground plane necessary for transmitting and receiving. The design micro strip antenna consists of a patch and modified rectangular ground plane which is d esigned using dielectric constant 2. Microstrip antenna or patch antenna basics in antenna and.
Once your ground plane gets large enough, the finite ground plane effects should be negligible. Note that the better ground conditions give a lower angle. Usaf antenna research and development program, oct. An analytical technique to determine the effects of finite ground plane on the radiation characteristics of a microstrip antenna is presented. The size of your pcb will have an effect of the performance of your selected embedded antenna as well. Most radiation analyses of microstrip antenna are based on the assumption of an infinite ground plane. The fringing fields around the antenna can help explain why the microstrip antenna radiates. Gps patch integration application note antenna solutions. Bandwidth improvement of microstrip patch antenna using. Bandwidth enhancement of uwb microstrip antenna with a. The effect of a ground near any antenna for example. The patch is of length l, width w, and sitting on top of a substrate some dielectric circuit board of thickness h with permittivity. Baissinot, flat aerial for ultra high frequencies, french patent no.
Also, many different researchers have studied the effects of ground plane size on the bandwidth and radiation patterns. I understand that a patch antenna has a radiation pattern similar to the following picture from wikipedia when the patch antenna is centered over the ground plane. These are design parameters of antenna due to ground effect. Actual environments are different, and the ground plane is necessarily limited. Since monopole antennas rely on a conductive surface, they may be mounted with a ground plane to approximate the effect of being mounted on the earths surface. The finite ground plane effect on the microstrip antenna. In this article a broadband microstrip patch antenna is designed with slit incorporated in the rectangular ground plane.
Even though the slot theory can only be employed for rectangular patch and copolar calcula tion, the gtd, however, can be combined with other theories, such as. The halfwave rectangular microstrip antenna has a virtual shorting plane. Many comparisons between theory and experimentation are presented. A ground plane is a useful tool to combat digital crosstalk, which is strictly speaking an internal emc phenomenon. Effect of ground plane deformation on electrical performance. Here rectangular patch and partial ground plane is used. Similarly as the slot width increases the resonant frequency. A metal patch mounted at a ground level with a dielectric material inbetween constitutes a micro strip or patch antenna. The term has two different meanings in separate areas of electrical engineering. The induced currents on the ground plane and on the upper surface of the patch are determined from the discontinuity of the near field produced by the equivalent magnetic current source on the physical aperture of the patch.
A quarterwave monopole is a ground plane dependent antenna that must be fed singleended. It is found that for a monopole antenna like a quarter wavelength vertical, the ground acts as a plane to reflect the radio waves so that an image of the top half of the antenna is seen in the earth. The bottom of patch is filled with ground but the layer adjacent to the ground filled layer is a power plane. The amount of reduction depends on the extent to which the ground plane extends beyond the patch area. Therefore, as you increase the size of your ground plane, you need to redetermine where to feed the signal so as to minimize impedance mismatch loss. If the antenna is connected to a good earth ground, it is. In terms of the operation of a monopole, the reflection in the ground means that it appears that there is an image of the top half of the antenna below the ground in other words like a vertical dipole. The antenna must have a ground plane to be efficient, and ideally the ground plane should spread out at least a quarter wavelength, or more, around the feedpoint of the antenna.
The patch antenna, microstrip transmission line and ground plane are made of high conductivity metal typically copper. In verticals, something below must provide ground to complete the rf wave. The effect of simulated return loss, swept gain and radiation pattern of the proposed antenna have been obtained due to variation of slit dimensions. Enhanced bandwidth of uwb microstrip antenna using uslot. All the dimensions of proposed antenna are given in table 1. And the effect of the coaxial cable, the changes of the impedance, and the. Effect of ground plane size on a rectangular microstrip patch. International journal of electronics and communication.
Effects of ground plane size on a square microstrip patch. The finite ground plane effect on the microstrip antenna radiation patterns abstract. This is usually achieved with radials, either attached to the base of the vertical, or buried below a ground mounted antenna. Since the image is 180 degrees outofphase with the antenna and effectively the same distance below ground as the antenna is above ground, it becomes obvious there will be a null along the ground with a horizontally polarized antenna. Consider the side view of a patch antenna, shown in figure below. While this conceptual framework has served us well for over 100 years, it tends. I have looked online a bit and it seems to me that the general belief is that the larger the ground plane up to a certain extent, the better. Some antennas are designed with etched ground plane. The source field from the radiating patch is calculated by two different methods. In telecommunication, a microstrip antenna usually means an antenna fabricated using. This antenna is often built of printed circuit board material and the substrate makes up the patch antennas dielectric.
In this paper, we show the influence of the dimensions and the shape of the support. For this it appears that the ground plane is large enough. Note that since the current at the end of the patch is zero open circuit end, the c. This assumes that there are no earth or grounding losses. This antenna is often built of printed circuit board material and the substrate makes up the. By em ploying the gtd m ethod, the edge e ffect of the grou nd plane has been.
Lengthtodiameter effect makes the antenna a little longer electrically. A thicker substrate increases the gain to some extent, but may lead to undesired effects like surface wave excitation. Micro strip antenna consists of a very thin metallic strip placed on a. The ground or radials are the other half of the antenna. The effect of the radiation from the antenna and the conductor loss are. The uniform geometrical theory of diffraction gtd is employed for calculating the edge diffracted fields from the finite ground plane of a microstrip antenna. The patch antenna, microstrip transmission line and ground plane are. The effect of a fin ite ground plane on circularly polarized microstrip antennas has been studied. How exactly a ground plane helps inproving antenna gain. How will the ground plane effect your embedded antenna. A lot goes into designing antennas but with a little bit of guidance and explanation, antenna users network designers, systems integrators, end users can read through the antenna specifications and choose the right antenna style for their wireless network design. Results show that the tshaped ground plane with the presence of the diagonal cuts at the top corners and the rectangular slots can increase the bandwidth.
Selecting the right antenna gain for the application is the subject of much analysis and investigation. Aug 14, 2015 today we talk about the rf ground, what it is and when its necessary. In this paper a microstrip patch antenna is designed with rectangular ground structure with slit loaded on the ground plane to both enhance the performance and reduce the dimension. Meanwhie the takeoff angle appears to be in the range of 15 to 20 degrees for most cases at low heights. Microstrip patch antenna is a low profile, light weight, low cost, ease of. The planar invertedf antenna has been the subject of many different parametric studies to optimize the design. Microstrip patch antennas mpa are a class of planar antennas which have.
These are preliminary notes, intended only for distribution among the participants. More details on setting up the simulation and helpful tips can be found in the quarterwave monopole example. Antenna theory wire antennas monopole antenna long wire or traveling wave antennas yagi uda antenna reference. To make a smaller product, many commercial antennas have ground planes that are only slightly larger than the patch. The design of proposed antenna the design of the proposed antenna is shown in figure 1. Effects of ground plane size on antenna gain electrical. The proposed antenna provides very good result such as high gain, large bandwidth, and minimum return loss and better compactness. Influence of the ground plane structure on the radiation pattern of. The earth ground below the antenna, a conducting surface a. The vertical antenna is a monopole antenna, not balanced with respect to ground. The only change that needs to be noted is that the impedance of a monopole antenna is one half of that of a full dipole antenna. The patch is attached to the ground plane by foam, providing firm connections and flexibility in bending. The basics of patch antennas, updated orban microwave. This variant has better matching than the standard patch.
Analysis of the effects of rectangular ground plane on. In antenna theory, a ground plane is a conducting surface large in comparison to the wavelength, such as the earth, which is connected to the transmitter s ground wire and serves as a reflecting surface for radio waves. Its not feasible to center the antenna in the devices i worked on, so wed kind of shove the antenna. The larger the ground plane, the higher the antenna gain in general. These are very low size antennas having low radiation. The effects of ground plane size on the characteristics of a square microstrip patch antenna designed on a lowpermittivity substrate with an air gap were investigated. Figure 1 from ground plane effects on planar invertedf.
The size of the ground plane of your embedded antenna will effect the performance. What is the optmized size for a ground plane for micro strip antenna. Ictpituursi school on wireless networking for development the abdus salam international centre for theoretical physics ictp, trieste italy, 5 to 24 february 2007. The gain of an omnidirectional antenna can be increased by narrowing the beamwidth in the vertical or elevation plane. In this antenna, one corner of the patch or sometimes one edge is grounded with a ground pin. The ground or reflector seems to be about 12 inches square, as the 8dbi patch is 4. The ground or any large conductive surface plays the role of the second conductor of a dipole. The antenna is designed following the conventional design steps by applying duality theorem to it in order to excite the te modes.
I am designing a four layer board in which a patch antenna is used for a gps receiver. The radiation pattern of monopole antennas above a ground plane are also known from the dipole result. Pdf effect of a finite ground plane on circularly polarized. This study presents a new, simple method for reducing the backlobe radiation of a microstrip antenna msa by a par tially removed ground plane of the antenna. Effect of ground plane for enhancing the bandwidth and. Antenna theory and antenna terminology can seem complicated to the uninitiated. The antenna system requires a ground plane for the radio wave to form. The thickness of the ground plane or of the microstrip is not critically important. This means that an exceedingly good antenna rf ground is required. The finite ground plane effect on the microstrip antenna radiation.
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