What is electric dipole antenna?

What is electric dipole antenna?

A dipole antenna commonly consists of two identical conductive elements such as metal wires or rods. The driving current from the transmitter is applied, or for receiving antennas the output signal to the receiver is taken, between the two halves of the antenna.

What is dipole antenna and how it radiates its radiation field?

Similarly, the current in the dipole establishes a magnetic field encircling the dipole as shown, which also moves away from the antenna. The electric and magnetic fields together form the radiated electromagnetic field.

What type of radiation pattern is produced by a Hertz dipole antenna?

The radiation field pattern of a Hertzian dipole is the plot of |E| as a function of θ at a constant r. Hence, it is proportional to sin θ, and it can be proved that it is a circle.

Do I need to ground a dipole antenna?

A dipole does not need a ground. However, you can connect your station to a DC ground to comply with NEC (National Electrical Code). You might want to consider an isolation 1:1 transformer (https://www.balundesigns.com/1-1-baluns/ ). Dipoles should not be grounded, it will unbalance the load.

What is the function of dipole antenna?

Dipole antennas are used in many areas, both on their own and as part of more complicated antennas where they can form the main radiating element. They are used in many forms of radio system from two way radio communications links, to broadcasting broadcast reception, general radio reception and very many more areas.

How do you extend a dipole antenna?

To raise the frequency of minimum SWR, trim the antenna shorter. Cut each of the dipole’s segments by equal amounts so that the two halves maintain equivalent lengths. If the minimum SWR is minimized at a higher frequency than desired, you must lengthen the wire segments.

What do you need to know about the dipole antenna?

The dipole is any one of a class of antennas producing a radiation pattern approximating that of an elementary electric dipole with a radiating structure supporting a line current so energized that the current has only one node at each end.

How is the dipole of an electric field defined?

The electric dipole moment associated with two equal charges of opposite polarity separated by a distance ‘d ’ is defined as the vector quantity having a magnitude equal to the product of the charge and the distance between the charges and having a direction from the negative to the positive charge along the line between the charges.

What kind of antenna is called Hertzian dipole?

This type of antenna is called a Hertzian dipole, after the German physicist Heinrich Hertz. The magnetic vector potential generated by a current distribution is given by the well-known formula (see Sect. 4.12 ) Suppose that the wire is aligned along the -axis, and extends from to .

What happens when the size of the dipole increases?

As the dipole gets larger, the input resistance increases, along with the reactance. At slightly less than 0.5 the antenna has zero imaginary component to the impedance (reactance X=0), and the antenna is said to be resonant . If the dipole antenna’s length becomes close to one wavelength, the input impedance becomes infinite.