how to apply dc bias?

[ceyhunkirimli]

Can we apply dc bias internally or externally when making impedance scan by using AIM 4170C? Thanks...

[ceyhunkirimli]

i want to apply 0V-3V at most.

[Bob]

DC bias for a component for testing requires using an external blocking capacitor. The capacitor should have a relatively low reactance at the frequency of interest. For example, at 1 MHz a 0.1uf cap could be used. The calibration loads (short, open, resistor) can be attached after the capacitor to compensate for it's effect.

--73/Bob

[ceyhunkirimli]

I may have give inadequate explanation in my previous post. I connected an HP E3631A DC power supply unit to the input of AIM4170 C which is in parallel with a piezoelectric sensor that operates between 2.5MHz and 5MHz range. When i increase the voltage from 0-700 mV everything was ok. After i exceed 700 mV AIM4170C measures a phase angle of 90(mostly) or -90 degrees. I want to apply DC bias to the piezoelectric sensor because i suspect it may become more sensitive for reason i cannot explain here. Could you explain where i need to connect a capacitor? I do not understand what you mean by calibration loads? Do i need to calibrate again? What do you mean by compensation for the capacitor.? Thanks again

[Bob]

Here is a diagram showing the external components for DC bias:
www.w5big.com/DC_Bias_for_DUT.png

--73/Bob

[ceyhunkirimli]

Thank you so much... I will order the necessary circuit elements and give it a try.