What is major lobe in radiation pattern?
In a radio antenna’s radiation pattern, the main lobe, or main beam, is the lobe containing the higher power. This is the lobe that exhibits the greater field strength. The sidelobe in the opposite direction from the main lobe is called the “backlobe”.
What is back lobe in antenna?
The side lobe directly behind the main lobe is called the back lobe. The longer the antenna relative to the radio wavelength, the more lobes its radiation pattern has. In transmitting antennas, excessive side lobe radiation wastes energy and may cause interference to other equipment.
What does minor lobe usually represent?
Minor lobes usually represent radiation in undesired directions and should be minimized. Side lobes are normally the largest of the minor lobes. The level of minor lobes is usually expressed as a ratio of the power density, often termed the side lobe ratio or side lobe level (SLL).
What is the use of radiation pattern?
A radiation pattern defines the variation of the power radiated by an antenna as a function of the direction away from the antenna. This power variation as a function of the arrival angle is observed in the antenna’s far field.
What is the radiation pattern of an antenna?
A typical directional antenna radiation pattern in polar coordinate system representation, showing side lobes. The radial distance from the center represents signal strength. A typical antenna radiation pattern in cartesian coordinate system representation showing side lobes.
What are the side lobes of a radio antenna called?
The other lobes are called ” side lobes “, and usually represent unwanted radiation in undesired directions. The side lobe directly behind the main lobe is called the back lobe. The longer the antenna relative to the radio wavelength, the more lobes its radiation pattern has.
What are the disadvantages of a side lobe antenna?
Another disadvantage is that confidential information may be picked up by unintended receivers. In receiving antennas, side lobes may pick up interfering signals, and increase the noise level in the receiver. The power density in the side lobes is generally much less than that in the main beam.
What does the direction of a radiation pattern mean?
The direction of this lobe indicates the directivity of the antenna. The other parts of the pattern where the radiation is distributed side wards are known as side lobes or minor lobes. These are the areas where the power is wasted. There is other lobe, which is exactly opposite to the direction of main lobe.