The firestik firefly lg3m2lg4m2 no ground plane antenna kit with molded side mount is a great antenna kit for rv or any other. Analysis of the effects of rectangular ground plane on. Many com parisons between theory and experimentation are pre sented. Meanwhie the takeoff angle appears to be in the range of 15 to 20 degrees for most cases at low heights. Antenna fundamentals an antenna is a device for converting electromagnetic radiation in space into electrical currents in conductors or viceversa, depending on whether it is being used for receiving or for. Ictpituursi school on wireless networking for development the abdus salam international centre for theoretical physics ictp, trieste italy, 5 to 24 february 2007. Antenna gain relative to a dipole antenna can be expressed in decibels as dbd.
The outer conductor terminates in the ground plane and the inner conductor connects to the end of the helix. The polarization of an antenna refers to the orientation of. Before starting to build the antenna, you can stiffen up ordinary 14 gauge copper. The history of radio engineerings term antenna pdf. Pdf in this paper, the design of a ground plane that does not produce drastic transmission loss despite of its electrically small size is. A ground plane is a useful tool to combat digital crosstalk, which is strictly speaking an internal emc phenomenon.
High performance 40 meters vertical without radials. The antennas size and shape largely determines the. A transmitting antenna transforms electric currents into radio waves and a receiving antenna transforms an electromagnetic field back into electric current. A ground plane antenna is more of less one half of the dipole and mounted above the ground plane. Antenna theory wire antennas monopole antenna long wire or traveling wave antennas yagi uda antenna. Whats the difference between a dipole and a ground plane. Following pictures are examples of different types of antennas. The magnetizing field or h plane lies at a right angle to the e plane. The radiator, which is based on a microstrip patch. It works fine with low swr, but nearly all the repeaters i want to reach are northish of me and i dont just dont have enough umph to make it into the further ones. Foundations of antenna engineering kildal antenn ab. I needed a simple portable ground plane for the local ares y2k deployment, where i would be stationed at one of the local fire stations. Find, read and cite all the research you need on researchgate.
Ground mounted antennas are often very easy and convenient to use. Index terms directivity, far field, finite ground plane, monopole antenna, radiation pattern. I wanted high efficiency 40 meter antenna with lowangle radiation. A no ground plane antenna is designed to use the ground or water to transmit horizontally. Trying to make 14 wave 2m ground plane directional qrz forums. They will then also be able to download a greyscale. A monopole antenna is a type of dipole antenna formed by replacing one half of the dipole antenna with the ground plane at a right angle to the remaining half. Blog antenna ground plane calculation arcadian antenna. Ground currents all around the antenna make the image work. If the ground plane is large enough, the monopole behaves exactly like a dipole because its reflection in the ground plane forms the missing half of the dipole. In telecommunication, a ground plane is a flat or nearly flat horizontal conducting surface that serves as part of an antenna, to reflect the radio waves from the other antenna elements. The building had a flat asphault roof, about 15 feet up, and i wanted to use my 2meter 58wave magneticmount whip. Pdf ground plane size reduction in monopole antennas for. That image isnt an actual current or dipole at the position of the image antenna.
At one end a rf source is connected and other end is. The electric field or e plane determines the polarization or orientation of the radio wave. Another way to look at vertical antennas 1notes appear on page 32. Crosstalk coupling between two tracks is mediated via inductive, capacitive and common ground impedance routes, usually a combination of all three figure 5. To recover the spherical wave spectrum of the finite ground plane source as if.
The amountsize of the groundplane required for the optimal performance of a monopole antenna is determined by the frequency you are transmittingreceiving at. It is used as a geometrical technique in calculating the radiation pattern of the antenna. Study of the quarter wave vertical 20m antenna with. Tc 964 communicationselectronics fundamentals wave propagation, transmission lines, and antennas july 2004 distribution restriction. Radial attach each radial with a 632 screw, lockwasher and nut 20. The paper presents the design and investigation of a flexible alltextile antenna operating in the wireless body area network wban ultrawideband uwb specified by the ieee 802.
Makes the antenna a little longer electrically thicker conductors are longer electrically. The image antenna just represents all of the currents induced in the ground all around the antenna. This disadvantage can be somewhat offset, however, by the ability to mount the shorter antenna in the center of a surface that will act as an acceptable ground plane e. Vhf and uhf antenna systems 1821 fig23these drawings illustrate the dimensions for the 144mhz groundplane antenna. There are many types of antennas depending upon their wide variety of applications. Enhanced bandwidth of uwb microstrip antenna using uslot. 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. There are updated free pdf versions of the book available subject to registration via. Figure 4 shows the return loss graph of antenna with uslot and ground plane which is finite one. These are preliminary notes, intended only for distribution among the participants. Patch and ground plane design of microstrip antennas by. For this it appears that the ground plane is large enough. An antenna counterpoise, or ground plane, is a structure of conductive material. The idea is simple enough hang a wire vertical from a support, using two elevated but sloped radials to form a basic ground plane antenna.
Ground plane gain equivalent to 2 dipole 3element yagi may have up to 5 dbd gain 20. Due to the variety of methods of analysis and design, and the. On the continuum of antenna designs between a ground plane antenna and a coaxial vertical dipole, why is it that sometimes there is a welldefined optimum size of the ground plane, or rather the antenna element which is not pointing upward, whereas sometimes it doesnt seem to matter much. The proposed antenna features an innovative and compact uwb radiator on top of the overall structure with a full ground plane on its reverse side. Communicationselectronics fundamentals wave propagation. This conductive mechanical device is the transducer that converts the radio. Groundplane antennas for 144, 222 and 440mhz for the fm operator living in the primary coverage area of a repeate r, the ease of construction and low cost of a 14.
The gain for the ground plane is very nearly constant and equal to an isotropic antenna at low heights and real ground conditions. In which i describe what quarter wave monopole antenna is, give mathematical description along. It provides good impedance matching and higher bandwidth. Pdf infinite ground plane antenna characterization from limited. A ground plane antenna is a form of dipole antenna designed to work with an unbalanced feed line. The image antenna for a dipole over perfect earth is a dipole at the same distance below. Antenna theory 8 antenna can also be termed as an aerial. 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. An antenna is a device that provides a transition between electric currents on a conductor and electromagnetic waves in space. Ground plane is partial providing good impedance match with width 30mm and 8mm length. Introduction onopole antennas are half the size of their dipole.
In this view, we retain the concept that ground is an. 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. Ease of fabrication and cost makes the ground plane antenna one of the popular antennas in communication systems. In this case, its a multiband antenna the customer is using it can be used from 700 mhz 2700 mhz so the ground plane required could be anywhere from 464 square inches. Radial slowly twist the wire while pulling it to keep it taught. Ushaped slot is used to decrease the overall antenna impedance. Study of the quarter wave vertical 20m antenna with elevated ground plane explanation of the models calculated swr an swr of 1. Thus, an antenna with a gain of 3 dbd would have a gain of 5. Since the radials are elevated, the ground losses are minimized, even though there are only two of them. In radio engineering, an antenna is the interface between radio waves propagating through. This shortened easytobuild vertical, with noradials, is made from surplus military camouflage poles. For a horizontallypolarized antenna, the h plane usually coincides with the verticalelevation plane. Study of the quarter wave vertical 20m antenna with elevated. Cypress can provide a list of suitable antenna design specialists, if requested.
The following symbols are used to describe the helix and ground plane as shown in fig. In telecommunications and antenna design, an image antenna is an electrical mirrorimage of an antenna element formed by the radio waves reflecting from a conductive surface called a ground plane, such as the surface of the earth. A ground plane antenna is a variant of the dipole antenna, designed for use with an unbalanced feed line such as coaxial cable. Most antennas reversibly link radiation fields to currents flowing in. It resembles a coaxial antenna whose lower section consists of straight elements called radials instead of a hollow conducting cylinder. Updated with color and gray scale illustrations, a companion website housing supplementary material, and new sections covering recent developments in antenna analysis and designthis book introduces the fundamental principles of antenna theory and explains how to apply them to the analysis, design, and measurements of antennas. It has gain and wave angle comparable to a fullsized ground plane antenna with radials. A no ground plane antenna will not perform as well as a traditional cb antenna of the same length, but in situations where you do not have an adequate ground plane such as on a boat, rv or motorcycle, they do the trick. Next, we apply the previous results to the case of a circularly polarized antenna, in order. Note that the better ground conditions give a lower angle. Due to its image in the ground plane dotted lines, a monopole antenna has the same radiation pattern over perfect ground as a dipole antenna in free space. Antenna design and rf layout guidelines cypress semiconductor. Nowadays, antennas have undergone many changes, in accordance with their size and shape.