My Homemade Circular Polarized Antenna

by Random_rc | May 21, 2014 | (0) Posted in Just Fun

 

My Homemade 5.8Ghz Circular Polarized Antenna's

I have reacently made a cloverleaft and a skew-planar antenna. i have a few tips as well.

 When i was testing these antennas on the transmitter, after 5 min or so it had hardly changed in temperature, where with the stock antennas the transmitter would get warn(change in about 5-15 degrees celsius(49 - 59 degrees Fahrenheit.). the reason why i think the transmitter doesn't get hot is because the SWR is lower than the stock antennas( i don't have a SWR meter yet but hopefully i will get one (when i do i will post another artical about it)) so this means that the TX shouldn't get hot from the reflected RF power. 

This is my cloverleaf 

This antenna goes on the transmitter(TX)

This is my skew-planar

This antenna goes ont the receiver(RX)

 

Tips about building:

  1. when measuring the length of the copper lobe make the distance a little longer like insted of 52.65mm (or something else) cut it to 53mm because the wire cutters aren't always on the edge of the cuters they are usually around <1mm. 
  2. same with bending the wire, make it a little bigger (not too much bigger other wise it wont be accurate.
  3. also if you are not sure just play around and cut one then meaure it and if it is shorter then increase the lenght and then go back once you have cut it and measure the actall distance.
  4. once you are happy with the lobes dip the tops in paint like i did. They look nicer and won't oxidise.
  5. it is easier to get a premade cable but i crimped the cables myself.
  6. i used sf- 142 which is a higher quatilty than rg 142 wich is better the rg316 (less loss in the cable)

Cable

 it is quite hard to se but it says "SF-142"

Here is the data sheet : SF-142 

 

 

these antennas are much better than the standard liner antenna(stock)

 

i am using the foxtech fpv reciever, so i need a Rp-SMA

here are the connectors

here are some more photos

 

 

A youtube video might be coming out later of the fpv test comaring to the stock antennas

COMMENTS

Chad on May 24, 2014
Nicely done. Great tips
The specs on that coax are good in fact like you said much better than most in fact a great choice. (http://disti-assets.s3.amazonaws.com/cdmelectronics/files/datasheets/4719.pdf link to spec sheet) You are also correct about transmitter efficiency. the better the antenna the more effective radiated power from the antenna you will get. you can also change the wire diameter of your elements which can also effect center frequency and bandwidth increasing/decreasing performance.
Keep up the good work.
Log In to reply
Random_rc on May 24, 2014
thanks, I have now added the data sheet, but the link that you posted didn't work for me. hopefully a video will come out later of a fpv flight with my ft Versa(it is ready just have to find a day)
Log In to reply
Random_rc on May 24, 2014
it works but I have to remove the extra bit. because when I paste it in the browser it adds in extra stuff ( I think it has something to do with flite test)
Log In to reply

You need to log-in to comment on articles.


My Homemade Circular Polarized Antenna