S2-LP loop antenna design

[Jan Buurman]

Hi,

For an engineering project I've got a S2-LP and would like to use it in combination with a loop antenna. The S2-LP has a RXp and RXn output. Usually a balon is used to go from balanced to unbalanced output (50 ohm). In this case a BALF-SPI2-01D3.

I would like to connect my loop antenna directly to the RXp and RXn output. What is the impedance of the RXp and RXn output?

A loop antenna is required as a normal antenna is detuned very easily. The modules are potted, underwater in close proximity to steel. I'm stuck with the S2-LP chip and 868MHz. This is far from ideal but cannot be changed.

Thanks in advance,

[Jan Buurman]

The question is not answered. But I've got a working device in the harsh environment described.

I understand now this forum is not for these kinds of questions...

[DUpps.2199 · Accepted solution]

In table 17 and table 27 in the S2-LP datasheet the impedances for RX and TX are mentioned.

I assume you tune the loop after it is potted and close to the steel? Did you try other types of antennas as well?

[Jan Buurman]

Thanks for the answer. I've overlooked the table. The project is finished.