1MHz circuit diodes, which ones?

[T3sl4co1l]

The AC input and DC output cannot BOTH be common to the same ground reference.

You need isolation.

Tim

[alsetalokin4017]

It's deja vu all over again.... 

[alsetalokin4017]

I don't know either. The input signal is a very clean sinusoid.
So if I understood correctly there isn't much I can do to see a rectified signal with 1N4148s (uless I work with much higher voltages)?

Schottky BAT54 are only with 3pins? Is there any equivalent with 2 pins?

It is likely that your Function Generator's output BNC shield is grounded to the FG's chassis which in turn is grounded to the mains, and so back through the mains to your scope probe's ground reference lead. So when you connect one scope probe to the output of the bridge in the "usual" manner (probe tip to bridge + and probe ground clip to bridge -) you are in fact creating a groundloop between the AC input from the FG to the output of the bridge. So you are seeing a distorted signal and only one-half of the bridge output.  To get around this problem you either need to use an expensive isolated differential voltage probe on the bridge output, OR make a differential measurement of the output using two scope channels, no probe ground connections, and math to subtract, as I showed in the scopetraces I posted on the previous page.

If you want your bridge to work well at 2V input then Schottky diodes are probably necessary. 1n5817 for example.

If you are set on using surface mount BAT54 series diodes you can use one BAT54A and one BAT54C, or two BAT54S, to construct your FWB. These contain two diodes each, in common-anode (A) and common-cathode (C)  and series (S) connections. The plain BAT54 (no letter suffix) has three leads also but only contains one diode and the third lead is not connected internally. But they are in tiny SOT-23 packages!

[raff5184]

thanks alsetalokin4017 I'll try with a differential measurement as you showed in other posts.

I saw the schematics of the different BAT54's, now it makes more sense why there are two diodes.
I'll first try with 4 BAT54 (I already ordered them) and than with the other solutions you suggested.
Since the third pin is not connected, can I ignore it?

Sorry guys if these questions are basic but I have no practical experience and don't know where to find this information, which diodes are used, what they are called and so on. I know the theory but apparently it doesn't help. But thanks to you I'm getting a grasp on these topics 

[alsetalokin4017]

No offence intended, but with "no practical experience" I'm wondering how you are going to be working with SOT-23 package devices..... but yes, you can ignore the non-connected pin on the BAT54. Usually it will be soldered to a pad for mounting purposes but not connected electrically to anything.

[raff5184]

no problem alsetalokin, no offense.
I'll learn step by step, read guides that I can find on the Internet, trial and error... I have to start somewhere.

Btw if you know any good PRACTICAL guidebook feel free to suggest it.
Thanks

[alsetalokin4017]

If you are set on using the BAT54 diodes you may want to look at getting some adapters or breakout boards that will allow you to mount your SOT23 devices and use them like standard DIP or SIP packages on your breadboard. There are many manufacturers and vendors of these things. You can solder the SOT23 pins with a fine-tipped iron and very thin solder. It may take some practice...