OOK decoding, wrong polarity with very strong antenna signal

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I am developping a receiver uising Philips (NXP) UAA3220, wired as a OOK superheterodyne receiver.
if the receiver is far enough from the transmitter, the digital decode output is OK.
When the receiver is at about 30..40cm from the transmitter, the RF frontend get overloaded, and there are no output signal.
When the receiver is at about 20cm, the output reappears, but in REVERSE polarity !!!
I don't figure what happens.
Normally, for a RF amplifier, we must reach a compression point in overloaded condition. Is it possible that, for heavily overloaded condition, the gain decreases with the increase of input signal?


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[Manuel]

Probably U mean AGC.
Yes it's possible, but a specific design have to be drawn.
I'd say you are having saturation problems now.
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