Antennas- Multiple/Simultaneous Frequencies

[Mikebits]

Maybe you can post the advertisement, and allow us to evaluate it.

 

[dknguyen]

It's kind of every page for all their air receivers:
Spektrum RC

 

[Tesla23]

Oh yeah, I've been talking about wire antennas the whole time. None of those special dual polarity ones.

What initially sparked this question (in case it's gotten lost), was the receiver had two antennas- each oriented 90 degrees to each other.

?? Are you sure it mightn't be a dual polarity antenna ??

 

[dknguyen]

?? Are you sure it mightn't be a dual polarity antenna ??

Pretty sure. THe antennas are just straight pieces of wire- no fancy coiling or anything. Is that what you mean?

The spatial and polarity diversity is supposed to come from placing the base units and satellite units at different locations in different orientations (except for the odd unit where the antennas are mounted in different directions which provide polarity diversity in the same unit).

THe two smallest units have just one antenna- I know these ones do not transmit on dual frequencies.

 

[Tesla23]

Pretty sure. THe antennas are just straight pieces of wire- no fancy coiling or anything. Is that what you mean?

Two antennas at 90 deg is typically a dual polarisation antenna. You might be thinking helical antennas and circular polarisation.

Look it's impossible to say what the system does, but I did have a quick look at the claims of US patent 7,391,320, they claim to use a combination of transmit diversity (that's an interesting one), along with frequency diversity, path diversity, time diversity, antenna diversity and polarization diversity (orig claims 24-26). If you downloaded the patent it is likely that they will give you lots of details of how the system might work.

 

[Mikebits]

Those guys are using CDMA/GSM type technology... So it is like like FDMA.