Amplifying the 2.4ghz spektrum

[rclinks2002]

Hello,
I am currently working on a project that requires a 2.4ghz radio system. I have ran into a small range issue with the spektrum radio system from horizon hobby. I was wondering if anyone knew what sort of amplifier I would need. I would assume that a wireless (802.11b/g) linear amp would work but I would like clarification. Thanks
Ben M

[dalbert02]

I would say you would be better off using a higher gain antenna. It would be cheaper and work as well. 3db gain is the same as 10 times your amp power.
-dave

[vector_vortex]

While there are some amps that would do the job no worries, it really should be built into the system. At 2.4Ghz when PCB trace lengths have to be spot on for impedance matching an aftermarket add on this is going to be difficult. Check out Maxim's MAX2421 or TI's TRF1123 maybe a prebuilt evaluation board could be the way to go as those components are mighty small.

Have Fun

[treehog]

http://www.rcgroups.com/forums/showthread.php?t=657685

came across this innglider forum today

any ideas

[macboffin]

2.4 gigs is the frequency that micro-wave ovens utilise; it is the excitation frequency of water molecules. It is NOT a good idea to be around 2.4 gigs at much more power than the DX7 puts out, and even that amount may have long-term health effects.
Boiled brains, anyone?

[Gary Mortimer]

I had been wondering if this 2.4 Ghz gear is a good thing for health reasons.

It would'nt take much for them to make a breakout transmitter that sits on the roof of your car and communicates via bluetooth perhaps with higher gain antennas on it.

G

[hihptsi]

2.4 gigs is the frequency that micro-wave ovens utilise; it is the excitation frequency of water molecules. It is NOT a good idea to be around 2.4 gigs at much more power than the DX7 puts out, and even that amount may have long-term health effects.
Boiled brains, anyone?


i like my brains fried... in a burrito with lotsa sour cream and hot sauce.

[bzfrank]

(2.4 Ghz) is the excitation frequency of water molecules

No, the lowest excitation frequency of water is indeed 22.23 GHz.

[dalbert02]

My microwave says 2450Mhz on the label inside...
-dave

[Dan_Jones]

Gary, they already have your car mounted amplified antenna! I saw on future weapons a device for crowd control that uses millimeter wavelengths to cause warming pain in humans. They said it causes water molecules to vibrate in our skin but it only penetrated the outer surface of the skin.

http://www.govexec.com/features/0501/0501s4s2.htm

I want to support the first few posts that suggested better antennas. From what I have seen, that is the cheapest and easiest way to maximise performance without causing more cancer (or hair loss in my case.. :D )

Dan

[vector_vortex]

For the microwave does not use the excitation frequency of the molecule but heats due to the dipole moment. Apparently there are 915Mhz microwaves too. This leads to the 915Mhz ISM band for spread spectrum communications.

see: http://en.wikipedia.org/wiki/Microwave_oven#Description

For the millimetre wave crowd control system see.
https://www.jnlwp.com/ActiveDenialSystem.asp
especially the movies.

[E.N.]

Check out the ExtremeLink systems. Boast 5miles range LOS.

Ian:cool:

[treehog]

I mean the RC is unit is hung low down and is the signal hitting below the belt :eek:

Am I going to breed two headed geekerherz ;)

oh why didnt I stick to stamp collecting and get cancer of the tounge instead from licking horse glue on stamps :)


Ralf

[Medve]

Very simple guys. Just wrap everything you want to keep, noggin, family jewels, etc. in aluminum foil to stop the diaelectric heating. he he he I can just see it now at the local field. "hey Bob, I'm outa foil, can I borrow a chunk"? OK OK, just messin with ya all, but I guess it is something keep in mind when we hit microwave range.

[actionplus]

Well, from the tests I have done.
The range plus the throughput of the 2.4G wireless will degrade quite a bit. Hopefully there is not many microwave ovens out in the fields :p

Anyway, I think that is why they are also using it in conjunction with the S.Sprectrum technoloy. Helps with the inference.

As far as boosting the power.
Use these PA. RFMD 5163. It should provide you with at least 26dBm of power. If that is too much, try the RFMD2126.
I suggest good terminations. Don't want to have it reflecting back into the antenna and over-heating your system.

Hope that helps.