Abstractthis paper presents the effect of the slots in ground plane and patch on resonant frequency, impedance bandwidth, gain and side lobe. In this paper, we show the influence of the dimensions and the shape of the support. In the introduction it was mentioned that the enclosure and the components close to the embedded antenna like battery or display will interfere. 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. What is the optmized size for a ground plane for micro. An analytical technique to determine the effects of finite ground plane on the radiation characteristics of a microstrip antenna is presented. The microstrip antennas have been designed on er 4. There are usually four radials, three being a minimum, but you could use up to six. The gain of an omnidirectional antenna can be increased by narrowing the beamwidth in the vertical or elevation plane. Whats the difference between a dipole and a ground plane. The partial ground plane removal reduces the backlobe radiation of. A typical mobile cb antenna does not transmit horizontally, it radiates in a downward pattern. The ground plane is used for directing the electromagnetic energy in the forward direction. The antennas feed is a through hole and reaches the bottom of board, where it meets a 50 ohm transmission line.
The earth ground below the antenna, a conducting surface a least. 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. Because of the artificial ground provided by the radials, the height above ground should have little effect on this type of antenna. How will the ground plane effect your embedded antenna. In this article a broadband microstrip patch antenna is designed with slit incorporated in the rectangular ground plane. Patch antennas can show a very high gain, especially if they are mounted on top of a large ground plane 70 x 70 mm. Here, the practical resonance shifts to the lower from the aforementioned 5. The enhancement of bandwidth and virtual size reduction are achieved without altering the size of the rectangular patch and nature of broadband radiation characteristics. The ground plane is a conductor and metals reflect electromagnetic radiation. For a situation where the signals of interest are below the antenna in elevation e. Citeseerx effect of slots in ground plane and patch on. In this paper, the geometrical theory of diffraction gtd r. The patch is attached to the ground plane by foam, providing firm connections and flexibility in bending. 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 design and analysis of printed antenna with the reduced ground plane effect, fed by micro strip line for ultra wide band uwb communication systems is presented. In this paper we have introduced a new concept of strip lined truncated ground plane for inset fed microstrip patch antenna. This paper presents the effect of the slots in ground plane and patch on resonant frequency, impedance bandwidth, gain and side lobe. Citeseerx document details isaac councill, lee giles, pradeep teregowda. Once your ground plane gets large enough, the finite ground plane effects should be negligible. The size of your pcb will have an effect of the performance of your selected embedded antenna as well. The simulation results show that the gain of a circular patch antenna varies with the ground plane size. A groundplane antenna is more of less one half of the dipole and mounted above the ground plane.
How exactly a ground plane helps inproving antenna gain. A typical gain pattern for a quarter wave ground plane antenna is. The main disadvantage of these antennas is their relatively large size compared to other types of antennas. A metal surface the larger and flatter, the better is required underneath the cb antenna to launch the signal out into the atmosphere. Note that the signal is now fed singleended and that the ground plane acts as the return path. Making the ground plane larger also increases the gain, but as the ground plane size increases, diffraction near the edges plays less of a role and increasing the size of an already large ground plane has very little effect on gain.
Effects of ground plane size on a square microstrip patch antenna designed on a lowpermittivity substrate with an air gap, 2010 international workshop on. In reality it is very difficult to get an antenna rf grounding system that is lossless and it is accordingly difficult to fully realise this gain. The simulated results indicate that by cutting an elliptical patch at radiator, the proposed antenna yields a wide operating bandwidth of 2. Many numerical and measured results are presented to demonstrate the accuracy of. Effect of ground plane size on a rectangular microstrip. My understanding is that when building or installing an antenna designed to operate over a ground plane e. In the antenna in figure 1, the center conductor of a coaxial line serves as the feed probe.
Ease of fabrication and cost makes the groundplane antenna one of the popular antennas in communication systems. The slots on the patch or on the ground plane will help to design a. The effects of ground 31 chapter 3 the effects of ground t he ground around and under an antenna is part of the environment in which any actual antenna must operate. Effect of partial ground plane removal on the radiation. Most antennas on the pcb are implemented as quarterwave antennas on a copper ground plane. I am designing a four layer board in which a patch antenna is used for a gps receiver. It uses the standard formula, 234f mhz to calculate the element lengths. As this antenna can only radiate above the ground plane, a monopole antenna will have a gain of 3 db over an equivalent dipole. For example, some patch antennas are approximately half a wavelength on each side. Influence of the ground plane structure on the radiation. As we know the current distribution on the ground plane of the conventional patch antenna mainly concentrates just under the patch, as shown in figure 3, which is the vector current distribution of the resonant frequency 5. Actual environments are different, and the ground plane is necessarily limited. Patch antenna ground plane electrical engineering stack. This assumes that there are no earth or grounding losses.
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. Selecting the right antenna gain for the application is the subject of much analysis and investigation. You typically need a half wave ground plane to minimize frequency shift. The source field from the radiating patch is calculated by two different methods. Chapter 2 dealt mainly with theoretical antennas in free space, completely removed from the influence of the ground. Most radiation analyses of microstrip antenna are based on the assumption of an infinite ground plane. 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. I used to work for a company that made electronics with gps patch antennas in them.
The size of the ground plane of your embedded antenna will effect the performance. 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. It has been observed as the slot length increases the resonant frequency. An elliptical patch uwb antenna with reduced ground plane.
Patch antenna ground plane effect on radiation pattern. The magnetic conducting patch and ground planes replace the electric conducting patch and ground plane. A groundplane antenna is a form of dipole antenna designed to work with an unbalanced feed line. Ceramic patch antennas are very popular because of the low costs and the huge variation of available sizes 40 x 40 mm down to 10 x 10 mm. The antenna is designed following the conventional design steps by applying duality theorem to it in order to excite the te modes. This chapter is devoted to exploring the interactions.
In microstrip patch antennas, a radiating patch sits above a substrate and below the substrate there is a ground plane. Does mounting a ground plane antenna upside down change. Amazons choice for ground plane antenna nagoya gpk01 21 radials nmo mount ground plane kit for base or field use, so239 connector, mounts to 2 pole, mast, pipe 4. This paper presents effect of slots on microstrip patch antenna and its parameters. How to predict groundplane effects on patch antenna.
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. The uniform geometrical theory of diffraction gtd is employed for calculating the edge diffracted fields from the finite ground plane of a microstrip antenna. I currently work for a different company that makes electronics with gps patch antennas in them. The ideal patch is unbalanced, so you should have most of the surface current distribution on the patch surface. Study the ground plane effect of a multiband antenna for. The developed antenna was found to operate at an uwb frequency of 10. The effect is shown on bandwidth, gain, radiation pattern, return loss, axial ratio and size of an antenna. Citeseerx effect of strip lined truncated ground plane. The image is a tool for understanding the earths effect on 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. This study presents a new, simple method for reducing the backlobe radiation of a microstrip antenna msa by a partially removed ground plane of the antenna. Ground mounted antennas are often very easy and convenient to use. Patch antennas come in various shapes and sizes and consist of a patch of metal directly above a ground plane.
The basics of patch antennas, updated orban microwave. This calculator can be used to design a quarter wave ground plane antenna, with radials. Effects of ground plane size on antenna gain electrical. The patch antenna, microstrip transmission line and ground plane are made of high conductivity metal typically copper.
This page allows you to calculate the length for a quarter wave ground plane antenna. Effect of ground plane for enhancing the bandwidth and. The effect of simulated return loss, swept gain and radiation pattern of the proposed antenna have been obtained due to variation of slit dimensions. The effect of the partial ground plane removal in different configurations on the radiation characteristics of a msa are investigated numerically. An antenna ground plane is not to be confused with an electrical ground.
The bottom of patch is filled with ground but the layer adjacent to the ground filled layer is a power plane. As the name indicates the antenna ground plane acts as a. Passive patch antenna application note ground plane effect on gain for apae series patch antenna is a passive component and therefore, its gain is defined as antenna directivity times the radiation efficiency. Effect of slots in ground plane and patch on microstrip. Its good to have 1 wavelength ground plane size, but half wave. The horizontal radiation pattern is a circle where the antenna radiates equally well in all directions. If the ground plane is too small, the antenna shifts frequency, and thatll kill your sensitivity much more than the patterns going askew. The below patterns are taken from scans of a 25mm25mm2mm patch on an extended 35mm groundplane. 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. To investigate the effect of the ground plane size on the radiation characteristics of an msa, a conventional msa with a full metallic ground plane that operates in the dominant mode tm. It has been observed as the slot length increases the resonant frequency shifted to the lower side by 19. The finite ground plane effect on the microstrip antenna.
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