What is the radiation pattern of folded dipole antenna?

The radiation pattern of half-wave folded dipoles is the same as that of the half-wave dipole antennas. Half-wave folded dipole antennas are used where optimum power transfer is needed and where large impedances are needed. This folded dipole is the main element in Yagi-Uda antenna.

What happens when dipole antenna is folded?

A folded dipole is an antenna, with two conductors connected on both sides, and folded to form a cylindrical closed shape, to which feed is given at the center. Hence, it is called as half wave folded dipole antenna. The directivity of Folded dipole Antenna is bi-directional. The input impedance is higher.

How is a folded dipole antenna better than a half wave dipole antenna show the input impedance of a folded dipole antenna is 292 Ω?

Explanation: The impedance of folded dipole is four times the impedance of the half dipole. So its impedance is higher than the half dipole. Since folded dipole is a balanced antenna we use a balanced feeder so Balun is used. It is a dipole antenna with two ends folded back and connected to each other forming a loop.

How is the radiation pattern of folded half wavelength dipole antenna?

The radiation pattern of a half-wave dipole has the shape of a doughnut. 6. What is the beam width for a half wave dipole antenna? Explanation: The beam width is measured between the points on the radiation curve that are 3 dB down from the maximum amplitude of the curve.

What is the importance of folded dipole antenna?

One of the main reasons for using a folded dipole antenna is the increase in feed impedance that it provides. If the conductors in the main dipole and the second or “fold” conductor are the same diameter, then it is found that there is a fourfold increase (i.e. two squared) in the feed impedance.

Why folded dipole antenna is used in Yagi antenna?

The folded dipole is a standard approach to increasing the Yagi impedance. It is widely used on Yagi antennas including the television and broadcast FM antennas. The simple folded dipole provides an increase in impedance by a factor of four.

What is the impedance of two folded dipole antenna?

The antenna impedance for a half-wavelength folded dipole antenna can be found from the above equation for ZA; the result is ZA=4*Zd. At resonance, the impedance of a half-wave dipole antenna is approximately 70 Ohms, so that the input impedance for a half-wave folded dipole antenna is roughly 280 Ohms.

What happens when the radiation resistance of the antenna matches?

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.

Why is half dipole preferred over other dipole antennas?

Most important thing about half dipole antenna is radiation analysis. It gives more directive pattern as compared to one dipole antenna. GAIN is high. It’s length (half of the wavelength) gives you the better performance than other lengths…..

Can a dipole antenna be bent?

One way to fit a dipole antenna in a restricted space is to bend the legs. They can be bent horizontally, drooped downward, or any other imaginable configuration to fit in the space available.

What is the gain of a dipole antenna?

When mounted horizontally, the radiation peaks at right angles (90°) to the conductor, with nulls in the direction of the dipole. Neglecting electrical inefficiency, the antenna gain is equal to the directive gain, which is 1.5 (1.76 dBi) for a short dipole, increasing to 1.64 (2.15 dBi) for a half-wave dipole.

Is the radiation pattern of half wave folded dipoles the same?

The radiation pattern of half-wave folded dipoles is the same as that of the half-wave dipole antennas. The following figure shows the radiation pattern of half-wave folded dipole antenna, which is Omni-directional pattern.

What does a folded dipole antenna look like?

The folded dipole antenna consists of a basic dipole, but with an added conductor connecting the two ends together. This makes a ‘loop’ of wire that is a short circuit to DC. As the ends appear to be folded back, the antenna is called a folded dipole antenna. The basic format for the folded dipole aerial is shown below.

What is the impedance of a folded dipole?

For the instance for a three wire folded dipole, with all wires or conductors having he same diameter, the impedance is increased by a factor of three squared, i.e. 9. This means that the nominal value for a folded dipole with three conductors is 9 times 73Ω or approximately 600Ω

Can a unbalanced feeder be used on a dipole antenna?

Unbalanced feeders can be used provided that a balun (unbalanced to balanced transformer) is used. The additional part of the folded dipole antenna is often made by using a wire or rod of the same diameter as the basic dipole section. However this is not always the case.

What is the radiation pattern of folded dipole antenna? The radiation pattern of half-wave folded dipoles is the same as that of the half-wave dipole antennas. Half-wave folded dipole antennas are used where optimum power transfer is needed and where large impedances are needed. This folded dipole is the main element in Yagi-Uda antenna. What…