Ground Plane Of Antena

I can t understand why we need to use a ground plane at 1 4 wavelength and not at 1 2 wavelength.

Ground plane of antena. As the name indicates the antenna ground plane acts as a simulated ground. I know that an antenna that has half a wavelength does not need the ground plane example a dipole antenna and when using a wavelength of 1 4 it is usually necessary to have the ground plane planar antennas pcb. A ground plane antenna is a form of dipole antenna designed to work with an unbalanced feed line. An antenna ground plane is not to be confused with an electrical ground.

This is a simulated ground made from a sheet of conductor which typically extends out to a quarter wavelength from the antenna. A ground plane antenna is more of less one half of the dipole and mounted above the ground plane. Our antennas are designed and manufactured to provide the best gain figure for the requirements of the band. The plane does not necessarily have to be connected to ground.

A typical mobile cb antenna does not transmit horizontally it radiates in a downward pattern. It resembles a coaxial antenna whose lower section consists of straight elements called radials instead of a hollow conducting cylinder. A ground plane antenna is a variant of the dipole antenna designed for use with an unbalanced feed line such as coaxial cable. 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.

The one pictured below is for receiving ads b aircraft signals on 1090mhz again using scrap copper but this time a purchased n type chassis socket. Often the conductor is simulated by a number of radials often a quarter wavelength long. 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 antenna consists of a button shape outer cylindrical structure and an internal central via connected to a top disc at one end and the metal ground plane at the other.

There are two or more radials each measuring 1 4. What is an antenna ground plane. Clarification needed ground plane shape and size play major roles in determining its radiation characteristics including gain. 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 ground plane antenna packed with specially made gp antenna mounting hardware. Below is a quarter wave ground plane antenna i made for 23cm 1296mhz which is made from off cuts of household mains copper wire and a scrap bnc socket from the junk box. Read more about the antenna ground plane. Many vertical antennas employ what is called a ground plane.