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AD9361 TX 1A/2A Port Matching

Question asked by mike.baker Employee on Feb 17, 2015
Latest reply on Feb 23, 2015 by tlili

I’m trying to get a handle on the matching networks for RX1A/2A and TX1A/2A.


I need one of each to match  to 2.4GHz and the other to match to 415MHz single ended. I have the RF Port Interface matching document and the eval board schematic. From the RF Port matching document (Figure 4) it looks like at 415 MHz the Zdiff is about 200 ohms which would require a 200ohm balanced to 50 ohm unbalanced balun and at 2.4 GHz a 50 ohm to 50 ohm would be fine, just as the eval board schematic shows with the 12450BL15B050 Johanson balun. However I don’t see a corresponding curve that shows Zdiff for the TX1A/2A ports. Do the TX 1A/2A ports follow a similar curve as the RX1A/2A where I can assume that Zdiff is 200ohms for TX1A/2A?


My other source of confusion is on the TX ports where the eval schematic doesn’t show 1.3V connected through inductors on the differential side of the balun, where the RF Port interface describes in detail that this is necessary and it should be able to source 75mA.


Any guidance would be appreciated.