# Thread: TX and RX port impedance of BGT24LTR11N16 ?

1. ## TX and RX port impedance of BGT24LTR11N16 ?

Dear support:

What is the accurate TX and RX port impedance of BGT24LTR11N16 ?
In Table 4 of the LTR11 datasheet, the TX load impedance is 50 ohm, and in Table 5, RX input impedance is also 50 ohm.
In fact, the impedance should be a complex, e.g. in datasheet of BGT24MTR12, the two RFIN port impedance are15.9-j18.4 and 15.7-j18.9.
I need the port impedance of LTR11 because I've to design a specified microstrip structure.

Best Regards,
Jhon

2. As said in the datasheet the impedance is characterized as 50Ohm with the test condition for TX/RX: Including TX/RX port matching structure according to AN472. See AN472 Section 3.

3. Originally Posted by leon
As said in the datasheet the impedance is characterized as 50Ohm with the test condition for TX/RX: Including TX/RX port matching structure according to AN472. See AN472 Section 3.
Dear leon, your said "the impedance is 50ohm with the port matching structure", so I think the impedance on the PAD is not 50ohm as in the datasheet, am I right? It shold be a complex value like those in BGT24MTR11. As said in datasheet of BGT24MTR11 (Infineon-BGT24MTR11-DS-v03_01-EN.pdf) the RFIN port impedance is 22.9-j14.9, the LO load impedance is 24.4-j25.8.
But I made some simulations with HFSS and ADS, assume the antenna side of the match structure is 50ohm, the impedance of the pad side is not equal to the (conjugate) value listed in the datasheet(22.9-j14.9 and 24.4-j25.8).

Are these values measured or calculated? And how the match structures designed?
I need to design a custom match structure, so I have to know the true value of the impedance on the pad.