What is the effect of side lobes in Yagi-Uda antenna?

The directional pattern of the Yagi-Uda antenna is highly directive as shown in the figure given below. The minor lobes are suppressed and the directivity of the major lobe is increased by the addition of directors to the antenna.

What is the radiation of a Yagi-Uda antenna?

What is the radiation pattern of a Yagi-Uda antenna? Explanation: Radiation pattern of a Yagi-Uda antenna is end-fire. It has its main beam parallel to the axis of antenna (boom). The addition of directors will increase the gain of antenna while reflectors will increase the directivity of antenna.

How does a Yagi antenna radiate?

A typical Yagi antenna has one reflector and one or more directors. The Yagi antenna propagates electromagnetic field energy in the direction running from the driven element toward the director(s), and is most sensitive to incoming electromagnetic field energy in this same direction.

What is the effect of back lobes in radiation pattern?

The minor lobes oriented at an angle to the main lobe are called “side lobes”. The minor lobe in the opposite direction (180°) from the main lobe is called the “back lobe”. Minor lobes usually represent radiation in undesired directions, so in directional antennas a design goal is usually to reduce the minor lobes.

What is meant by radiation pattern of an antenna?

The radiation pattern is defined as a mathematical function or a graphical representation of the far field (ie, for r≫2D2/λ, with D being the largest dimension of the antenna) radiation properties of the antenna, as a function of the direction of departure of the electromagnetic (EM) wave.

What is the radiation resistance of a half-wave antenna in free space?

Impedance for half-wave dipole antenna in free space is 73 Ω

Does a Yagi antenna need to be grounded?

The Yagi does not need to be grounded. However, we recommend a lightning surge protector in all building installations. The surge protector will prevent an electrical surge from damaging your amplifier.

What are the different lobes of principle radiation pattern of antenna?

Lobe Formation Here, the radiation pattern has main lobe, side lobes and back lobe. The major part of the radiated field, which covers a larger area, is the main lobe or major lobe. This is the portion where maximum radiated energy exists. The direction of this lobe indicates the directivity of the antenna.

How can I reduce my side lobes?

Sidelobe levels can be reduced by tapering the edges of the aperture distribution (changing from uniformity) at the expense of reduced directivity. The nulls between sidelobes occur when the radiation patterns passes through the origin in the complex plane.

What is the advantage of having reflector in Yagi-Uda antenna?

This can help in reducing the levels of interference received. Typically a reflector will add around 4 or 5 dB of gain in the forward direction. Director: The director or directors are made to be shorter than the driven element. There may be none, one of more reflectors in the Yagi antenna.

What happens when the radiation resistance of the antenna?

Explanation: When the radiation resistance of the antenna matches the characteristic impedance of the transmission line, the SWR is minimum and maximum power reaches the antenna. This allows maximum power to be transmitted.

What is radiation intensity of antenna?

Radiation intensity, or the antenna power pattern, in a given direction is defined as the power radiated from an antenna per unit solid angle. The radiation intensity is a far field parameter which can be obtained by simply multiplying the radiation power density by the square distance, i.e., (2.99)

Is a Yagi antenna better?

The antenna’s design filters out almost all signal noise coming from the opposite direction. This makes Yagis a good choice when you have a high demand application like telecommunications. It is easier to aim a Yagi antenna than some arrays.