series /parallel diode linearizer

[bhatt_190487]

Can anybody explain the function of series or parallel diode linearizer? or suggest me some references which contains the detailed explanation for it?

 

[chuckey]

There are two types, one type relies on the curve of the current against voltage of a forward biased diode.More then one diode can be used too give an extended voltage range. The other type regards the diode as "perfect" and uses different series resistors and DC bias voltages so the circuit sees a different impedance depending on which diodes are turned on by the DC bias being exceeded. The diode network is often used as part of the feedback network of an amplifier, so the diodes losses can be compensated for.
Frank

 

[bhatt_190487]

Thank you Sir for your reply . Here you mentioned about different impedances .Impedances means attaining different dynamic impedance of the diode? I am dealing with the parallel diode linearizer. I have take Rbias as 2kohm with Vds =5V bias supply and supplying Rf supply from -20 dBm to 20dBm. I am trying to plot the change in dynamic resistance with respect to increase in rf power supply . As per some papers ,the dynamic resistance should increase as the rf power supply increases but here my dynamic resistance decreases after 5dBm.Can you tell me why it is so?

 

[chuckey]

Can you show a circuit diagram, I suspect that the diode bias is being changed by the RF level.
Frank