Ground plane for patch antenna pattern

A naive response would be that the antennas pattern would be unaffected except to be rotated 180 degrees, i. Here, the solid ground plane is assumed to be sliced into 5 strips which they are symmetrical on current direction as shown in figure 1c. Radiation patterns of the circular patch with finite ground plane size are computed and compared with the experimental data, and the agreement is found to be good. 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. Patch and ground plane design of microstrip antennas by material. This calculator can be used to design a quarter wave ground plane antenna, with radials. A patch antenna is a type of radio antenna with a low profile, which can be mounted on a flat surface. Figure 2 present the simulated 2d cut view and 3d far zone eplane radiation patterns for this antenna.

The bottom of patch is filled with ground but the layer adjacent to the ground filled layer is a power plane. In a patch antenna, most of the propagation is above the ground plane and can have high directional gain. Endfed vertical jpole and horizontal zepp imax 2000 vertical. The patch antenna, microstrip transmission line and ground plane are made of high. 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. An analytical technique to determine the effects of finite ground plane on the radiation characteristics of a microstrip antenna is presented.

In this work, microstrip antenna with w and vshaped radiating patches have been proposed. An antenna ground plane is not to be confused with an electrical ground. The patch antenna in figure 7 shows how simple these antennas can be. The distance between the patch and the ground plane the. An antenna pattern measurement technique for eliminating the fields scattered from the edges of a finite ground plane. From this structure, it is clear that if the antenna is excited, there will be conductive currents on the patch and the middle strip, then generating the coupling currents among the strips and the patch as well as between the neighboring strips. A microstrip patch or array with infinite ground plane is a theoretical antenna, but patch with finite ground plane is of practical interest. Asymptotic method in prediction ofe plane radiation pattern of rectangular microstrip patch antennas an finite ground. Ground mounted antennas are often very easy and convenient to use. The substrate and ground plane size effect on radiation. Here square and circularshaped modified ground planes have.

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. Its good to have 1 wavelength ground plane size, but half wave can work though the antenna can start to detune a bit. The term monopole is also used to describe this antenna. To control the radiation pattern a fourfed circular patch antenna was modeled and. The ground plane antenna packed with specially made gp antenna mounting hardware. These results show that a microstrip patch antenna mainly radiates in the vertical direction. Effects of ground plane size on a square microstrip patch antenna. The main disadvantage of these antennas is their relatively large size compared to other types of antennas. The characteristics studied include return loss, gain, half power beamwidth hpbw, and radiation pattern. It is possible to simulate this function by replacing the real earth with a conducting plane. Pdf reconfigurable patch and ground plane microstrip antenna to. A metal surface the larger and flatter, the better is required underneath the cb antenna to launch the signal out into the atmosphere. Also the centre frequency of the antenna will changes in size of the groundplane. Influence of the ground plane structure on the radiation.

Effects of ground plane size on a square microstrip patch antenna designed on a lowpermittivity substrate with an air gap, 2010 international workshop on antenna technology iwat, lisbon, 2010. A typical mobile cb antenna does not transmit horizontally, it radiates in a downward pattern. The antenna efficiency is defined as the ratio of the radiated power to the input power. The characteristics studied include return loss, gain, halfpower beamwidth hpbw, and radiation pattern. One familiar application of this type of patch antenna is the. I used to work for a company that made electronics with gps patch antennas in them. The earth ground below the antenna, a conducting surface a. 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. Antenna product search contact vhf base loaded chrome coil antennas, no ground plane mhb5802s base loaded field tunable 3 db gain antennas mhb5800 and muf4503 series. The concept of infinite ground becomes even more important for arrays. The fundamentals of patch antenna design and performance. The patch antenna, microstrip transmission line and ground plane are made of high conductivity metal typically copper. The relative complex dielectric constant of the earth is. The radiation pattern of microstrip or patch antenna is.

Antenna experts manufactures ground plane antenna for 3066 mhz. This antenna is often built of printed circuit board material and the substrate makes up the patch antenna s dielectric. In general the companies that sell gps antennas suggest a ground plane minimum size. In slots of different shapes such as triangular or re9 ctangular were placed on the ground plane under the feed line of the radiator for bandwidth increasing and. One should read the text above to note that this text should be. The radiation patterns exhibit typical patch antenna characteristics. 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. The gain and hpbw varied periodically with increasing. Modeling infinite ground plane in antennas and arrays. In its most basic form, a microstrip patch antenna consists of a radiating patch on one side of a dielectric substrate which h as a ground plane on the other side. If the ground plane is too small, the antenna shifts frequency, and thatll kill your sensitivity much more than the patterns going askew. 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. In the following some results are reported for the patch moving on the diagonal of the ground plane, starting from the center see fig. The effects of the earth ground are included using the fresnel reflection coefficients.

Influence of the ground plane structure on the radiation pattern of. Pdf modified ground plane of patch antenna for broadband. A thicker substrate increases the gain to some extent, but may lead to undesired effects like surface wave excitation. Increasing microstrip patch antenna bandwidth by inserting.

Apart from the list appeared above we are experts to design and supply the ground plane antennas for out of bands antenna. 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. Patch antenna is a passive component and therefore, its gain is defined as antenna directivity times the radiation efficiency. Typical gain and axial ratio of a patch antenna with respect to ground plane size. An array of 16 wire patch antenna wpa fed by an integrated 16 ways power divider has been designed. The goal is to understand the radiation mechanism, polarization, patterns. These effects include frequency shift, gain, axial ratio and radiation pattern. Here the previously designed 8 element array with corporate feed, as shown in figure 6. The patch is of length l, width w, and sitting on top of a substrate some dielectric circuit board of thickness h with permittivity. The distance between the patch and the ground plane the substrate or dielectric height h determines the bandwidth. The radiated fields contributed by the induced current on the ground plane and the equivalent sources on the physical aperture yield the radiation pattern of the antenna. I currently work for a different company that makes electronics with gps patch antennas in them. Whats the difference between a dipole and a ground plane.

One familiar application of this type of patch antenna is the rectangular. Fringing fields in patch antenna 5 directivity and radiation pattern the radiation pattern of a standard patch antenna looks similar to that shown below in figure 5. Assuming losses in the reference antenna or the antenna used as a standard are minimal, all antennas obtain gain through pattern change. My trials at modeling this with eznec resulted in no change based on the antenna. As the number of elements increase the size of the ground plane increases dramatically as the space on the ground between the elements also needs to be meshed. The ag series is range of omni directional unity gain ground plane antennas that are ideal for local area coverage. Think of the ground plane being a metal roof of a vehicle and place the rubber duck antenna in the center with the antenna top end pointing straight up. Measurement of a circularly polarized patch antenna at 1. There are usually four radials, three being a minimum, but you could use up to six. Does mounting a ground plane antenna upside down change. The thickness of the ground plane or of the microstrip is not critically important. Typical radiation pattern of a 16 x 16 mm patch antenna figure 18.

What is the optmized size for a ground plane for micro. They are the original type of microstrip antenna described by howell in 1972. The antennas feed is a through hole and reaches the bottom of board, where it meets a 50 ohm transmission line. I am designing a four layer board in which a patch antenna is used for a gps receiver. 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. The position of the patch on top of the ground plane has effects on the radiation properties of the antenna similar to a variation of the size l. Effects of ground plane size on antenna gain electrical. Analysis of the effects of rectangular ground plane on. The car was modeled using a wire grid as shown in the figure.

In practice, monopole antennas are used on finitesized ground planes. All models are mounted at the roof height approx 25 feet above the ground to provide the maximum communication range and perfect omni directional coverage. A lowprofile antenna over a ground plane that radiates a directive lobe in the end fire direction is described in this paper. The basics of patch antennas, updated orban microwave. The influence of finite substrate and ground plane size on the radiation pattern performance of lprobe feed thick patch antennainpackage array in lowtemperature cofired ceramic ltcc for 60ghz wireless communications is investigated and compared when the antenna array is with and without the soft surface structure, which is used to reduce surface wave effect and improve the. While they have less reduction of rearward radiation than a larger design, they still have useful gain and directivity. A metal surface the larger and flatter, the better is required underneath the cb antenna to. A groundplane antenna is more of less one half of the dipole and mounted above the ground plane.

This is a simple rectangular patch built over a rectangular ground plane. It consists of a flat rectangular sheet or patch of metal, mounted over a larger sheet of metal called a ground plane. This affects the properties of the monopole antennas, particularly the radiation pattern2. Patch and ground plane design of microstrip antennas by. Ease of fabrication and cost makes the groundplane antenna one of the popular antennas in communication systems. The paper presents a broadband microstrip patch antenna for wireless communication. The wavelength corresponds to the velocity speed of the wave divided by its frequency. Owing to its low height, low cost, high robustness, and monopolar radiation pattern, the wpa has been chosen as unit cell of the array that must be placed on the. For example, some patch antennas are approximately half a wavelength on each side.

An antenna that is formed by etching out a patch of conductive material on a dielectric surface is known as a patch antenna. This is the vertical radiation pattern of a ground plane antenna over a socalled perfect ground. Typical gain and axial ratio of a patch antenna with respect to square ground plane size. As the name indicates the antenna ground plane acts as a. This design doesnt affect the frequency of operation. 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.

Patch antennas come in various shapes and sizes and consist of a patch of metal directly above a ground plane. William orr, radio handbook, 22 nd edition, howard w. The following image shows a microstrip or patch antenna. Also, the excitation to the antenna is provided using feed lines connected through the patch. The ground plane has substantial effects on the performance of the antenna. The dielectric material is mounted on a ground plane, where the ground plane supports the whole structure.

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