How to design a DC block circuit

[Sattek]

I repair Satellite receivers and I often need to block the DC voltage on the IF line to do the repair . I need to block 13-18 Volts between 900mhz and 2Ghz while obviously letting the AC signal pass. If anyone can suggest a simple circuit I would greatly appreciate it.

 

[xandeyes]

I have a bit curious, why do you need to block DC on IF line ?
IF line in satellite receiver is on feeder, right? which repair method do you apply without DC voltage ?

 

[KlausST]

Hi,

The usual way to block DC is a capacitor, connected in series.

Klaus

 

[Sattek]

I repair Satellite receivers and I often need to block the DC voltage on the IF line to do the repair . I need to block 13-18 Volts between 900mhz and 2Ghz while obviously letting the AC signal pass. If anyone can suggest a simple circuit I would greatly appreciate it.

I forgot to mention that the circuit impedance is 75 ohm.

 

[volker@muehlhaus]

As Klaus mentioned, just use a 100pF series capacitor.

 

[Sattek]

As Klaus mentioned, just use a 100pF series capacitor.

What about the circuit impedance? It needs to be coupled properly.

Thanks

 

[KlausST]

Hi,

You may calculate the impedance ...

Klaus