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bocchesegiacomo
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I can't understand how a ferrite rod antenna works. Someone can explain it to me?
Welcome to the PF.bocchesegiacomo said:I can't understand how a ferrite rod antenna works. Someone can explain it to me?
Electrical Engineering, or at least what is your background in electronics so far? If you are just starting out, that is fine. It's good to be curious and want to learn.bocchesegiacomo said:What is EE?
Nah, you could use a mere 75 meters also...Seriously, I have thought about the problem for hams using mobile antennae, where you have say a 6 foot whip and special matching networks to get say a 20 meter signal to go through a 2 meter long antenna. I thought about the idea of using a small airfoil attached to a long wire attached to the top of the whip and say you have a 3 meter long wire at right angles to the whip and held in space by the air going by the moving car. That would seem to me to reduce the tuning problem. Of course you better stop talking when the car stops:)berkeman said:Electrical Engineering, or at least what is your background in electronics so far? If you are just starting out, that is fine. It's good to be curious and want to learn.
Here is a tutorial about ferrite rod antennas that I found quickly with Google -- it looks pretty good.
http://www.radio-electronics.com/info/antennas/ferrite_rod_antenna/ferrite_rod_antenna.php
Ferrite rod antennas are used to make short receiving antennas when a normal (half wavelength size) antenna would just be too big. Like for AM radio stations, which are generally using a frequency band around 1MHz, so 1 wavelength is 300 meters. A 150 meter antenna would be kind of hard to fit in your car...
I know electronics quite well but i don t know much about magnetic fields, electromagnetic waves and antennasberkeman said:Electrical Engineering, or at least what is your background in electronics so far? If you are just starting out, that is fine. It's good to be curious and want to learn.
Here is a tutorial about ferrite rod antennas that I found quickly with Google -- it looks pretty good.
http://www.radio-electronics.com/info/antennas/ferrite_rod_antenna/ferrite_rod_antenna.php
Ferrite rod antennas are used to make short receiving antennas when a normal (half wavelength size) antenna would just be too big. Like for AM radio stations, which are generally using a frequency band around 1MHz, so 1 wavelength is 300 meters. A 150 meter antenna would be kind of hard to fit in your car... [emoji2]
Thank youberkeman said:Electrical Engineering, or at least what is your background in electronics so far? If you are just starting out, that is fine. It's good to be curious and want to learn.
Here is a tutorial about ferrite rod antennas that I found quickly with Google -- it looks pretty good.
http://www.radio-electronics.com/info/antennas/ferrite_rod_antenna/ferrite_rod_antenna.php
Ferrite rod antennas are used to make short receiving antennas when a normal (half wavelength size) antenna would just be too big. Like for AM radio stations, which are generally using a frequency band around 1MHz, so 1 wavelength is 300 meters. A 150 meter antenna would be kind of hard to fit in your car... [emoji2]
I am also able to use differential equations for electronicsberkeman said:Electrical Engineering, or at least what is your background in electronics so far? If you are just starting out, that is fine. It's good to be curious and want to learn.
Here is a tutorial about ferrite rod antennas that I found quickly with Google -- it looks pretty good.
http://www.radio-electronics.com/info/antennas/ferrite_rod_antenna/ferrite_rod_antenna.php
Ferrite rod antennas are used to make short receiving antennas when a normal (half wavelength size) antenna would just be too big. Like for AM radio stations, which are generally using a frequency band around 1MHz, so 1 wavelength is 300 meters. A 150 meter antenna would be kind of hard to fit in your car... [emoji2]
Ferrite rod antennas are commonly use for receive antennas because they are compact. They are not generally used for transmission, because they are not very efficient transmitters of that long-wavelength RF.bocchesegiacomo said:I asked you that question because I am interested in wireless transmission of Energy and maybe ferrite rod antennas can be Used for wireless transmission of Energy I have understood that that kind of antennas arent very efficient.
Not in the near field, but it does in the far field.bocchesegiacomo said:Ok thank you.but i did an experiment on wireless transmission with resonant coupling and i have seen that the inverse square distance law does not work
Here there is a photo about the concentration of the field on the resonant coil by wikipediaberkeman said:Not in the near field, but it does in the far field.
If you have a link to a mainstream paper about wireless energy transmission, you can link to it here and ask specific questions. Do not post any YouTube videos or links to papers by Nikola Tesla, etc. please.
That is no help at all.bocchesegiacomo said:Here there is a photo about the concentration of the field on the resonant coil by wikipediaView attachment 218552
And notice how the two coils are lined up closely, so there is a lot of coupling between them. That is how some electric toothbrushes are charged when placed in their holders next to the sink. That is not far-field energy transmission.bocchesegiacomo said:Here is the right imageView attachment 218553
A ferrite rod antenna is a type of antenna that uses a cylindrical rod made of ferrite material as its core. It is commonly used in radios and other electronic devices to receive and amplify radio signals.
A ferrite rod antenna works by converting the magnetic field of incoming radio waves into an electrical current. This is achieved by wrapping a wire coil around the ferrite rod and connecting it to a circuit, allowing the antenna to receive and amplify radio signals.
One advantage of using a ferrite rod antenna is its compact size, making it suitable for portable devices. It is also more sensitive to magnetic fields, making it effective for receiving weak signals. Additionally, it has a directional reception, which allows for better tuning and filtering of specific frequencies.
The reception of a ferrite rod antenna can be adjusted by changing the direction of the antenna. Rotating the antenna can improve the signal strength and quality. Additionally, adjusting the length and position of the wire coil around the ferrite rod can also affect the reception.
One limitation of a ferrite rod antenna is that it is susceptible to interference from nearby electronic devices and metal objects. It also has a limited frequency range, making it less suitable for receiving signals from very high or very low frequencies. Additionally, the reception can be affected by changes in atmospheric conditions.