All I can do is state the obvious MAWLER.
Check out the info at this site. http://www.satelit.cz/setkani/Dokumenty/PDF/mga86563.pdf
It has the Agilent specs and app. notes on the MGA-86563 MMIC amplifier. Double check the max input levels and matching suggestions.
Good Luck

Mawler,

Yes, we too have been experiencing an alarming number of field failures on the MGA86563.  Sent 5 for Failure Analysis in July 01 -- 2 cracked die, 3 each with lifted capacitor metalization.  Have had a recent rash of field failures, Icc ranging from 2mA to 170mA, all no gain.  Getting ready to send 6 more back for Failure Analysis.  Agilent APP engineer says few if any failures. What type and rate of failures have you seen?  Would like to discuss more.

I too have experienced problems with the MGA-86563, and would never use this device again. The problems I've seen have been more subtle:
1. Gain drop-out during thermal cycling.
2. Gain degradation over time.
3. Gain sensitive to moisture/safe-wash.
4. Low gain devices.

Reply to MAWLER on MGA-86563 problems:

Your MGA problems seem different to mine. I assume that you are using the MGA in the receive path of your system. If so, do you have any front-end limiting to protect the MGA from damage due to high-level received signals?

We also have had problems with this MGA part.  We designed a measurement tool which includes the MGA part and found, that over time, the gain degraded significantly.  This gain degradation appears to be in complete contradiction to the specification put out by the vendor (Agilent).  Has Agilent acknowledged and addressed this part deficiency?