Hello FvM,
Thanks for your feedback.
The layout is not the one that is recommended by freescale. The reason is, we want to reduce the size. So, we decided to go with 10.2 dielectric instead of 2.55 dielectric recommended by freescale. Using agilent ADS, we generated the layout for the impedance given in the datasheet for the operating frequency.
We also have the suspection that, the failure could be due to oscilations. Is there any way to avoid this? How to confirm this?
---------- Post added at 08:01 ---------- Previous post was at 07:51 ----------
After power ON, I terminated the input and measured the output in the spectrum analyzer for any spurious oscillations. But, nothing was visible. Also, when the output power was less than 200W , there were no oscillations observed from 50Mhz to 2GHz except the signal at 1030MHz. So, I thought that there was no oscillations and proceeded further by increasing the input power by 1dB where the failure happened (within a fraction of a second) . We observed a spark nearer to the drain side. After that there was no drain current, and the gate was showing short circuit.
By opening the failed device, We observed a burn nearer to the drain Pin and all the wire bonding has been burnt.
---------- Post added at 08:03 ---------- Previous post was at 08:01 ----------
If you want to see the photograph of the test module and the damaged device, Please send your mail ID. I will send email. Here I am not able to do any upload. My admin policy is not allowing this.