LOW POWER RF TRANSCIEVER?

[zarahmo]

please help.

we are currently using an easy radio rf module which can transfer data upto 250 meters and operates on low power. We need to extend this distance as far as possible for our application and it still needs to operate as a low power solution.
does anyone know of a different chip that is capable of over 1km data transfer?

kind regards,
zarah

 

[khouly]

try to increase the sensitivty of the receiver by adding LNA , with very low noise figure , but this will increase the receiver power
if u can manage this increase this solution will work

khouly

 

[polarized]

Hello,


If the system is using a loop antenna, try to change it maybe to a whip monopol antenna. For example, this is not really a mathematical approach, but in one system I have modified, I have simply cut the PCB loop antenna at one side and connected the "hot" end RF signal to a telescopic whip antenna. The whip antenna should have a GND area, but only under the antenna, not on the sides, as this will lower the range. I have 100m extra in range if I use the whip antenna instead of the loop antenna. The easiest way is to use a telescopic antenna due to mechanical reasons or a simple wire, of course calculate the wave lenght and make the antenna lenght equal to wave lenght/4 or similar etc...

 

[melc]

Instead of using a 0dBm output use a PA and extend the power up to +20dBm, than with a +15dBi antenna on both receiver and transmitter will run up to 8Km LOS or more... See Chipcon transcievers if you don't need too large bandwith and don't be so secretive with your transciever chip name...

 

[rigdoctor99]

And before you anything, find out if you are allowed to play on the frequency you are using....Do you need a licence......are you restricted in the distence you can transmit or the power you can use..............

COME ON PEOPLE, THERE ARE BAND-PLANS FOR A REASON...............

 

[biff44]

If you can point the antennas, go to high gain ones. that alone will get you the range.

Adding an LNA is good, but it will draw at least a couple mA, so not low power.

If the data rate is low, you could code the signal to get some coding gain. You would transmit maybe 5-10 times longer duration, but will go further.

 

[zarahmo]

All the suggestions are extremely appreciated!!! but i think what im after is recommendations of reliable, easy to use, low power, transcievers that could give me a long distance data download.

It has to be coupled with my ublox processor chip which can only handle a maximum of 14db in gain. My application is GPS tracking of animals. thus the further download distance i can get the better. I currently operate on a frequency of 434.00MHz.

any good suggestions are welcome. thank you.

zarah