"Level shifting" a 500MHz sinus signal

[luky315]

I have an AC coupled HF sinusoidal signal (0.1Vpp to 1Vpp) from a signal generator and need to level shift the signal to 0 to Vpp, idealy without manual adjustment. The problem is that I don't know for what to search - how is this sort of bipolar to unipolar signal "conversion" called?

[Ian.M]

At 500 MHz, anything active is going to be a PITA.  Feed a reversed Bias T with a DC source to offset its output.  Making the DC source track the peak amplitude will be a PITA, and a PITA² if the signal is AM modulated, so if you can live with a manually set DC offset, don't try to make it tracking!

[luky315]

The signal ist not modulated and should be relatively stable, but I get your point.
Would it be simpler to tie the 50R termination to a variable voltage?

[Hamelec]

more ore less a clamping (schottky) diode, but all depending of your load and your accepted DC failure..

[joeqsmith]

Would it be simpler to tie the 50R termination to a variable voltage?

Assuming your blocking cap can handle your bias voltage and you don't have any system level problems, sure.

[tszaboo]

So you could use a balun. Maybe one with a center tap, and drive that with 1/2 the peak voltage of the input?

[Marsupilami]

I have an AC coupled HF sinusoidal signal (0.1Vpp to 1Vpp) from a signal generator and need to level shift the signal to 0 to Vpp, idealy without manual adjustment. The problem is that I don't know for what to search - how is this sort of bipolar to unipolar signal "conversion" called?

I'm a bit confused by your input/output spec. Nevertheless this sound like the typical single rail ADC drive problem.

High speed opamps are your friend:
https://www.analog.com/en/products/ltc6253.html#product-overview

For a circuit you can start at:
https://www.analog.com/media/en/training-seminars/design-handbooks/Data-Conversion-Handbook/Chapter6.pdf


So far this is only manual, but you can use the 2nd opamp in the package of above device to integrate either the input or the output and feed it back to create the necessary V1 voltage for an appropriate mid level shift.
E.g. peak detector on the input as in https://sound-au.com/appnotes/an012.htm
If you need to scale the signal too automatically that's a bit more involved, but I'm sure you can solve it by throwing another opamp or two at it.

HTH

[radiolistener]

I have an AC coupled HF sinusoidal signal (0.1Vpp to 1Vpp) from a signal generator and need to level shift the signal to 0 to Vpp, idealy without manual adjustment. The problem is that I don't know for what to search - how is this sort of bipolar to unipolar signal "conversion" called?

if you have AC coupled signal, it means that it don't have DC coupling, so you can add DC bias from some power supply in order to get DC offset. Also you can add some voltage source in series with your AC coupled signal source.