How to measure the 2.4GHz differential port?

[yuhohang]

Dear all
Anyone have experience use the network analyzer to measure the 2.4GHz differential port impedance? Could you share you experience with us?
Best regards
yuhohang

 

[toonafishy]

Port 1 of network analyzer to one side and port 2 to the other. Take the S-PARAMETERS. You can mathematically combine then if so inclined but I am lazy. I just put them in a data blcok in @DS, add a termination that is not grounded and there is the S-parameter of the differential port.

 

[mike_bihan]

??

does not make sense to me. A little weird...

 

[jamez]

It really.

 

[mwpro]

Hi toonafishy,

do you mean that you put a s parameter port between the Port1 node and Port2 node. And the ground node is still connected to ground. Right?

 

[Phil woz ere]

Sounds Bluetoothy to me!

 

[toonafishy]

Yes, you connect the ground of the network analyzer test cables to the ground on your test board. The center conductor of port 1 cable goes to one side of the differential circuit. The center conductor of port 2 cable goes to the other side of the differential circuit. I use this method all the time to match differential output of a mixer into a differential SAW IF filter. I take the "single ended" S-parameter measurements, convert them to differential in @//D//S, then do the matching in the simulator, then solder the matching components down on the board. I can't think of any easier way to do this.

 

[toonafishy]

you may find this article helpful

See R/F D/e/s/i/g/n M/a/g/a/z/i/n/e Jan 1999 page 24.

also:

h**p://cp.literature.agilent.com/litweb/pdf/5988-5635EN.pdf

 

[yuhohang]

Anyone can post the page 24 of RF Design Magazine at Jan 1999?