AnsweredAssumed Answered

Mid Range Gain AD8367

Question asked by selenita on Jul 2, 2013
Latest reply on Jul 12, 2013 by selenita

Hello, I'm testing the AD8367 and i have one problem with the Gain

 

I use the L pad match resistors to adapt input and output to the GBF and spectrum analyser

 

My problem is that when i calculte the gain at midrange gain ( Vgain at 500 mV, usually 20 dB ) i find 2.5 dB

 

To claculate this the entry of the system is -16 dBm (-11.5 dB of Matching resistors ) and at the

output i have -11.5 dB the macthing resistors and the spectrum analyser measure in dBm.

 

Spectrum analyser measure is -36.5 dBm

 

When i calculate the Gain at 5 V Vcc i do :

 

Input is = -16 - 11.5 = -27.5 dBm

Output is = -36.5 + 11.5 = -25 dBm

G = -25 - (-27.5) = 2.5 dB

 

When i calculate the gain at 3V Vcc the gain is more little.

I think i have a problem with my calcul about the Z outputs.

 

The shematic is the eval board.

 

 

Thanks for your help.

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