0
There are two types of loop antenna used in radio, small and large. It is a loop of wire usually circular or square with the circuit (transmitter or receiver) connected at the two adjacent open ends.
A large loop is one wavelength in circumference and radiates a wave along the axis of the loop. It can also be thought of as a folded half-wave dipole.
A small loop also known as a magnetic loop is one tenth of a wavelength or less in circumference and radiates in the plane of the loop. Used as a receiver, a small loop gives an output signal voltage proportional to the magnetic component of the arriving radio wave.
Small loops for receiving can be made from a coil of wire on a ferrite rod, and this type of loop is also called a loopstick antenna.
Intermediate-sized loops have a rather unpredictable pattern so tend not be used.
What else can I help you with?
Can magnet be used as an antenna?
Yes, a magnet can be used as part of an antenna system, commonly known as a magnetic loop antenna. The magnet helps to concentrate and focus the radio frequency energy, improving the antenna's efficiency and performance. It is a popular choice for portable and low-profile antenna setups.
Why does my radio antenna only work when I touch it?
The radio antenna may only work when you touch it because your body is acting as a conductor, improving the antenna's reception by grounding it and reducing interference.
What expression can be found to represent the total work done by the agent pulling the loop?
The total work done by the agent pulling the loop can be represented by the expression "work equals force times distance."
How do you get a timer to work in a loop to slow it down in vb6?
You can use the Sleep function in VB6 to introduce a delay within your loop. This function pauses the execution for a specified number of milliseconds. Just insert Sleep(milliseconds) in your loop to slow it down.
Why is it necessary for circuits to maintain a closed loop?
Circuits need to maintain a closed loop to allow the flow of electric current. If the loop is broken, the current cannot flow, and the circuit will not work. This is essential for the proper functioning of electrical devices and systems.
What is Directivity of the small loop and short dipole has ratio?
The directivity of a small loop antenna is higher than that of a short dipole because the loop antenna is more directional and concentrates radiation in one direction. The ratio can vary depending on the dimensions and configuration of each antenna, but in general, the loop antenna can have a directivity several dB higher than the dipole.
What is the Radiation pattern of loop antenna?
cardioids
How loop antenna and dipole antenna can be used interchangeably?
A full-wave loop antenna can be interchanged with a folded dipole without much difference. The input impedance is similar and the only difference is in the directivity: a full wave loop radiates along the axis of the loop, while a vertical folded dipole is omnidirectional.
What did Andrew alford invent?
Andrew Alford is known for his work in developing the Alford loop antenna, a type of radio antenna. It is commonly used in shortwave radio receivers for its compact and efficient design.
Can magnet be used as an antenna?
Yes, a magnet can be used as part of an antenna system, commonly known as a magnetic loop antenna. The magnet helps to concentrate and focus the radio frequency energy, improving the antenna's efficiency and performance. It is a popular choice for portable and low-profile antenna setups.
What year was the aerial invented?
In 1888 Heinrich Hertz created a spark gap transmitter and a receiver sporting a loop antenna.
Why does my radio antenna only work when I touch it?
The radio antenna may only work when you touch it because your body is acting as a conductor, improving the antenna's reception by grounding it and reducing interference.
How you will identified antenna on aircraft?
When it comes to identifying an antenna on aircraft, there are a few types. Some of them are loop, master beacon, communication and loran antennas. Normally communication or com antennas can be found underneath the planes or on top.
How does a smart antenna work?
A smart antenna is used to identify signal signature and to track an antenna beam on the target. Some are for beamforming which is used to create the radiation pattern of the antenna.
When a vertical dipole antenna is used in conjunction with a loop antenna for direction finding then the field pattern obtained will be?
Loop antenna generate the same field as electrical dipole, but E and H are exchanged (a proof can be obtained this way: you align an electrical dipole with an axis, say z, and a loop antenna with z - you have to define surface orientation - then you apply duality theorem, calculate far field and you got it). For instance, in spherical coordinates (r,phi,theta) you have el. dipole {Etheta,Hphi} loop ant. {Ephi,Htheta} So, you can superpose the two fields and see that you have gained polarization independency (if an electrical dipole is aligned with z-axis and has its gap at z=0, it will receive very well Etheta, not at all Ephi (plane z=0), if you put a loop antenna "around" electrical dipole - like a ring around dipole's gap, lying on z=0 plane - it will receive very well Ephi (plane z=0) ). This is the way to make triaxial sensor, which have to be polarization independent.
What does antenna power overload mean?
it means take the antenna out of the power outlet, it won't work!
How does yagi-uda antenna differ from a folded dipole a loop antenna and a helical antenna?
Wow, your question on how a yagi-uda differs from a folded dipole, a loop antenna, and a helical antenna relates very much to how does a lawn mower engine relate to a V-8. The principals in all the antennas remains much the same. So I will deal with them in the order asked. The Yagi in its simplest form consists of 3 elements. The center element is the driven element and is essentially a dipole. Behind it is a slightly larger element called a reflector which does just that, it reflects signals to and from the dipole and in front there is the smaller director which helps focus energy. This is a directional antenna with gain. The folded dipole goes back to the basic dipole except it has makes a full loop. They are just as about as long as regular dipoles. With the loop of wire out there, they tend to have a wider band width than regular dipoles - but are not as tolerant of being used at even multiples of their cut frequency as the wires tend to cancel out each other. Oh, btw, yagi's have been made using folded dipoles. You must use ladder line or a 4:1 balun on folded dipoles, with perhaps the exception of the terminated folded dipole which has a resistor where the two elements of the dipole come together. The loop antenna? Which loop? I assume you are talking the traditional loop and not the magnetic loop. The full loop is normally computed to be 1005/frequency=feet. While you could take the time to tune the antenna, it might just be easier to put in a balun and an antenna tuner. The main advantage of a loop over the previous reviewed antennas is that it does fairly well even though fairly close to the ground where the previous 2 antennas should be at least 1/2 a wave length up for good performance. Helical antennas are generally good for just one band. In fact, due to the loading they cause they are best if used on a single frequency as their feed line requires them to be provided the connecting feed the is the electrical equivalent of a 1/2 wave at that frequency of operation. This may work well at VHF and above as an entire band can be tuned satisfactory, but in HF it would limit you to a very small segment of the band. Helical antennas definitely are the lawn mower engines of the antenna world. Look up antenna elmer on your favorite search engine. You have entered into a world where there is still a lot homework left to be done.
