BGT24LTR11 maching structures

[User15867]

What's the BGT24LTR11N16's output impedance on TX and RX ports? It does not specify numerical value anywhere in datasheets, only specify matching structure in AN472. However, that matching structure only works with 0.250 mm board thickness (10 mil). How do I match this IC to 20 mil thick board?

[Montassar-BR · Accepted solution]

Hi unnabi,

Here below the OUTPUT impedance of the TX and the RX port:



The matching should be evaluated with an RF simulator.
Way of matching for the TX (24GHz) transformation can be done with a MS taper and a quarter wavelength transformation, or via a MS taper and a 50 Ohm line + distributed GND cap (done in AN472)

Cheers,
Montassar.

[User14352]

Dear Montassar:

According to the matching structure for the TX and RX port in AN472 Fig13, I made a simulation with ADS. For the TX port, the ADS schematic is:



The TX port-impedance calculated with zin is about 116 + j0 ohm, and RX is about 112+j34.5, which are quite different with the values in your post.

What is the problem with my ADS model?

Thanks,
Jhon