Dipole Antenna
Dipole antenna
Dipole Antennas A dipole antenna is an antenna with a center-fed driven element for transmitting or receiving radio frequency energy. From a physics viewpoint, this type of antenna is the simplest practical antenna.
What are the advantages of dipole antenna?
Half-wave Dipole Antenna The operating frequency of this antenna ranges from 3 kHz to 300 GHz. The advantages of a half-wave dipole antenna are, they are not heavy, cost-efficient, its input impedance is similar to the transmission line's input impedance, etc.
What is the range of dipole antenna?
A calculable dipole antenna has been developed which is used to provide traceability for antenna factor over the frequency range 20 MHz to 2.2 GHz, to uncertainties as low as ± 0.15 dB.
What is dipole antenna and its types?
Dipole antennas are balanced in that they are bilaterally symmetrical, and they are fed with balanced, parallel wire RF transmission lines. There are three types of dipoles: Ideal half-wavelength dipole. Folded dipole. Hertzian dipole.
What is monopole and dipole antenna?
Antenna Elements and Arrays However: the monopole antenna has a field only in the top half of the space, having zero radiation below the ground plane. In contrast, the equivalent dipole structure has fields in both sides, with the radiation to the bottom side symmetric to that above.
Does a dipole antenna have to be straight?
Dipole antennas need not be installed in a horizontal straight line. They are generally tolerant of bending, sloping or drooping as required by the antenna site. Remember, however, that dipole antennas are RF conductors.
Where is dipole antenna used?
Dipoles are balanced antennas and are the most fundamental form of antennas. A standard dipole antenna has an omnidirectional radiation pattern. Dipole antennas are used in various applications such as in phased arrays and feeding sources to larger antennas.
What is the working principle of 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.
How long is a 20 meter dipole antenna?
20 Meter Dipole at 42 feet.
What is dipole antenna PDF?
The dipole antenna (Figure 5.19) is one of the simple and widely used antennas in ZigBee applications. This antenna consists of two wires (or traces on a PCB board). The size of each wire is approximately a quarter of the wavelength of the desired frequency of operation.
What is microstrip dipole antenna?
Microstrip antennas consist of a conductive strip, a dielectric substrate, and a conductive ground plane, and can be used to replace horn antennas for material characterization. From: Reference Module in Biomedical Sciences, 2021.
How is the dipole antenna polarized?
Further, the E-field only has one vector component and consequently the fields are linearly polarized. When viewed in the x-y plane (for a dipole oriented along the z-axis), the E-field is in the -y direction, and consequently the dipole antenna is vertically polarized.
Whats the difference between dipole and monopole?
In essence, the difference between a monopole and dipole antenna, is that a dipole antenna uses an additionally radiator to generate a synthetic ground plane between the symmetric radiator elements, where a monopole antenna requires a physical ground plane.
What is a monopole used for?
The monopole is often used as a resonant antenna; the rod functions as an open resonator for radio waves, oscillating with standing waves of voltage and current along its length. Therefore the length of the antenna is determined by the wavelength of the radio waves it is used with.
What is meant by monopole?
Definition of monopole 1 : a single positive or negative electric charge also : a hypothetical north or south magnetic pole existing alone. 2 : a radio antenna consisting of a single often straight element.
Does a dipole antenna need a ground plane?
Answer: No. The 1/2 wave antenna (also called a dipole antenna) is built of two 1/4 wave elements that interact with one another to launch the electro-magnetic wave. It does not require a ground plane to work efficiently.
Does the size of an antenna matter?
So the answer is yes, size does matter, but bigger isn't always better. It all depends on what your transmitting and receiving frequencies are. Theoretically, a longer antenna will have a greater range, but it is far more important for optimal radio performance that the length of the antenna matches the frequency.
How do you orient a dipole antenna?
Angle between dipole legs: The angle between the sloping wires must be at least 90° and preferably 120° or more. This angle dictates the centre support height as well as the length of ground needed to accommodate the antenna. Angle between dipole legs should be at least 90° and preferably around 120°.
How does current flow in a dipole antenna?
The charge and current on the dipole create fields that are perpendicular to each other. The electric field, E, flows from the positive charge to the negative charge placed on the elements by voltage applied to the antenna as shown in Figure 3(a).
Is a BalUn needed for a dipole antenna?
If a dipole antenna is fed with a coaxial cable from the transceiver, it is always a good idea to use a “BalUn”. BalUn means: Balanced to Unbalanced. This enables us to adapt an unbalanced fed system (coaxial cable) to a balanced antenna system (dipole antenna).
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