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Postby Axholt » Sun Feb 05, 2006 8:37 am

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Last edited by Axholt on Sat Jan 26, 2008 10:31 am, edited 1 time in total.
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Postby frank carcia » Sun Feb 05, 2006 9:18 am

The stage looks over loaded. The extra hump on drain voltage can be cleaned up with higher shunt C providing your FET can handle the power.
The ripples on the drain current are also related to over load. Try reducing the power to see if the waveforms improve. Your drive at 12 dBM is a bit low. The 3 volt bias will help but the drive impedance must be low enough to drive the gate properly. gfz
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Postby Axholt » Sun Feb 05, 2006 9:43 am

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Last edited by Axholt on Sat Jan 26, 2008 10:32 am, edited 1 time in total.
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Postby Axholt » Sun Feb 05, 2006 10:15 am

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Last edited by Axholt on Sat Jan 26, 2008 10:32 am, edited 1 time in total.
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Postby frank carcia » Sun Feb 05, 2006 11:26 am

Gee,
I was going to say look at your gate as it goes through the switch point.
Looks like a classic not low enough drive Z. Good luck!
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Postby Axholt » Sun Feb 05, 2006 1:00 pm

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Last edited by Axholt on Sat Jan 26, 2008 10:33 am, edited 1 time in total.
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Postby frank carcia » Sun Feb 05, 2006 2:19 pm

50 ohm drive Z is going to be high. You might need a driver stage.
input Z is almost pure C with some stray L based on your circuit layout.
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