Matching network on a 868 MHz transceiver

[edaenrico]

Hi,

I'm designing a 2-way 868 MHz remote control.

I'm gonna use a Texas Instruments RF transceiver.
The matching network is an ordinary L-C-L network.


How can I tune the L-C-L network?


Keep in mind that:

1. I got a spectrum analyzer

2. I got a broad band antenna

3. I might score a Vector Network Analyzer

4. RF simulators are fine as a starting point



Enrico Migliore

 

[FvM]

You didn't mention the remote control antenna. It's usually electrically small with a low radiation resistance and involving most of the matching uncertainties.

- You would start with an estimation, better measurement of the antenna impedance.
- Design a matching network for it, e.g. with classical Smith Chart design tool, connecting the nominal transceiver to the previously determined antenna impedance
- From this point there are different ways to correct/fine tune the matching network. It depends on how sure you are about the quality of the antenna measurement.

A direct way is to measure E.R.P in free field and tune the network if necessary.

Or try to assess the matching network performance by measuring network + antenna impedance from the transceiver side, possibly correct it. An E.R.P measurement will be the ultimate criterion anyway.

 

[tony_lth]

Try www.antune.net software, It's so easy.