Question about elements impedance in dipole antenna design

[jsp]

dipole antenna design

i have some question about the dipole antenna design

suppose u have tx output 50ohm
and matching 50 to 300
at that point two lamda/4 line then what should be the imp of the elements of just for electrical length it should be quarter wave

thanks in advance

 

[Element7k]

Re: dipole antenna design

Hi jsp,

r u talking abt a folded dipole?

Cheers,
Element7k

i have some question about the dipole antenna design

suppose u have tx output 50ohm
and matching 50 to 300
at that point two lamda/4 line then what should be the imp of the elements of just for electrical length it should be quarter wave

thanks in advance

 

[nec3]

Re: dipole antenna design

I think he asks for the elements for "antenna matching unit".
If so:
There is no specific elements for the whole band of frequency.Divide the band into 5 or more and designate values.This is the way how it is done in HF.

 

[jsp]

Re: dipole antenna design

yes it is about the folded dipole

pl give some tips

thank you

 

[flatulent]

bandwidth

The SWR bandwidth of a folded dipole is less than a cylindrical dipole of the same spacing between wires. It is very difficult to make a dipole of 10% bandwidth of SWR under 3:1.

On the HF band frequency assignments for a station are in narrow ranges. They use dipoles in parallel, one resonant for each band.

The popularity of the folded dipole is that you can feed it with 300 ohm parallel wire line which has low loss. This is good for the VHF band.

Since transmitters and receivers of all types are designed for 50 or 75 ohm lines, it is best to use a feed line and antenna at those impedances.

 

[Element7k]

Re: dipole antenna design

Hi jsr,

I think this is what you need. Hope it helps.

https://members.tripod.com/~KE4UYP/Feed_Line.html

Cheers,
Element7k

yes it is about the folded dipole

pl give some tips

thank you