VHF/UHF antenna for nanosatellite

[ladevita]

i want to design UHF/UHF antenna for nanosatellite. specific frequency use is 144-146 MHz for VHF and 430-440 MHz for UHF. Anyone can give me some advise or formula to calculated it,what type of material and type of antenna suitable to used. the dimension for satellite is 30cm X 30cm X 30cm. Thanks

 

[VEBill]

Flexible steel tape measure has been used. It has the advantage that it rolls up neatly and becomes straight when released.

Have you browsed the AMSAT website ?

Also, Google the 'Oscar' and RS-... satellites.

 

[Higgler]

More info would be nice;
1) does the antenna need to fit onto your satellite and lay flat against a 30x30 cm face? or can it extend outside of your volume. If it's mounted on your surface, how thick can it be, how heavy also?
2) antenna pattern shape? if the satellite spins, is this antenna suppose to be omni-directional. What's the Antenna Polarization? linear or circular?
3) Material depends partly on your satellite orbit location, LEO, MEO, GEO, etc.


Wavelength in inches is 11,803/Frequency in MHz.
Hence you have 82 inches at the low end and 27 inches for the high freq.
At 144 Mhz, that's an 0.15 wavelength antenna. That will be much more difficult to design than the higher frequency antenna.


If you can have these antennas pop up or uncoil, then little wire antennas or VE1BLL's tape measure shape would make life easy and low cost.

kch

 

[ladevita]

Thanx for the information u both give to me. it help me alot to design my antenna.
this is more information about the antenna i want to design.

1) the antenna will extend outside of the satellite and will deploy after it reach at orbit.
2)Antenna pattern shape is in omni-directional because we use 3-stability axis.
3)the antenna polarization still don't consider but maybe we'll use vertically polarization or horizontally polarization waves.
4) satellite will be located at LEO orbit at 600 km from earth.

if i want to use dipole for my antenna it is suitable to use Flexible steel tape?. to calculate the length Flexible steel tape can i use this formula 2952V/FMhz (1/4 wavelength)
v= coaxial cable velocity factor

may u give suggestion website that i can find more about Flexible steel tape propeties and price of this material?

 

[VEBill]

The one that I saw (on the WWW) used a tape measure from their local hardware store. IIRC the image from the on-board camera showed the tape measure antenna (yellow of course, complete with inch markings) sticking out into space with the Earth in the background.