schematic in keysight ADS issue

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oumik

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In the circuit below (both images are 1 entire circuit), I measured DC voltage at Vout and I obtained 0 V. The circuit is basically a power amplifier + power detector (with schottky diode) for RF source. This is the first time I use keysight ADS and I am not sure where I went wrong.
 

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No ADS problem, just a botched rectifier circuit. Look sharp, how can a diode with series capacitor produce DC output?
 

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FvM said:
No ADS problem, just a botched rectifier circuit. Look sharp, how can a diode with series capacitor produce DC output?
Click to expand...
Thank you for replying. The schematic is based on the 2 circuits shown below so from RF OUT we get an amplified signal which should be rectified by the schottky diode in the other circuit shown. I thought it might work but I guess not. Do you have any suggestions on how I should modify the circuit in ADS?

 

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You're doing a DC simulation but you expect a DC voltage from a RF signal.
It doesn't make sense..
You have to do HB simulation then you should see DC Harmonic Content of the rectified signal.
 

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BigBoss said:
You're doing a DC simulation but you expect a DC voltage from a RF signal.
It doesn't make sense..
You have to do HB simulation then you should see DC Harmonic Content of the rectified signal.
Click to expand...
Thank you for replying. So I have tried to do HB simulation. I modified the circuit as shown below (I removed the 1 nF and 1 MOhm) and added a Term in series with the diode. I obtained 2.999 dBm for the 2.4 GHz. Am I on the right track now? Please advise me if I am not as any suggestion would be helpful.
 

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No, you're not on the right way ..
For a rectifier, you should look at Vout[0] ( DC Component of the output waveform ) but there isn't filter capacitor.
Your DC value is too low , approx.-450dBm !!
 

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BigBoss said:
No, you're not on the right way ..
For a rectifier, you should look at Vout[0] ( DC Component of the output waveform ) but there isn't filter capacitor.
Your DC value is too low , approx.-450dBm !!
Click to expand...
Thank you for replying. You are referring to the 0 GHz right? What do you recommend to modify to increase the DC value ?
--- Updated ---

BigBoss said:
No, you're not on the right way ..
For a rectifier, you should look at Vout[0] ( DC Component of the output waveform ) but there isn't filter capacitor.
Your DC value is too low , approx.-450dBm !!
Click to expand...
Also, I am interested only in 2.4 GHz and not the other frequencies. Or is it that for all frequencies the values should be high ?
 
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If you place a RC filter at the Output then you look at Vout[0] in HB analysis, you will see a DC component what you want. Then either increase RF level or improve your amplifier. The rest is just a design problem.
 
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A small note : BFP420 is not a appropriate choice for RF rectifier circuit because it has very low driving capabilities.
It's a essentially low Noise BJT. I recommend you to use more powerful transistor.
 
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BigBoss said:
A small note : BFP420 is not a appropriate choice for RF rectifier circuit because it has very low driving capabilities.
It's a essentially low Noise BJT. I recommend you to use more powerful transistor.
Click to expand...
Thank you for you reply. I will take that into consideration.
 

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