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AD9361 RF input protection

Question asked by Alexittp on Mar 16, 2018
Latest reply on Mar 19, 2018 by Vinod

we’re currently using the AD9361 in a system where we need to protect the RF input against destruction of the AD9361.

 

Unfortunately, the maximum rating from the AD9361 datasheet only says +2.5dBm, but nothing about a time for which a transient would still be fine.

From our RF design guy, I’ve heard the +2.5dBm (0.84Vpp at 50 Ohm) is actually quite difficult to obtain with standard limiters/diodes.

 

I found a forum entry (https://ez.analog.com/thread/99130-ad9361-protection-in-continuous-wave) suggesting the use of the PE45361A-X

limiter, however, this limiter starts from +7dBm and there seems no other limiter available with a lower threshold which still works at 5 GHz.

 

Do you have any insights beyond the datasheet regarding the +2.5dBm rating?

(e.g. if +7dBm above simply drive the chip into saturation, or if levels around +7dBm actually destroys things and degrades the receiver performance?)

 

Are you aware of any other suggestions regarding RF input protection diodes or limiters suitable for the AD9361?

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