# Forward voltage Vf for diode...

#### Externet

Joined Nov 29, 2005
1,959
Hi.
Assuming 300mVf for a germanium diode D; how does rectification work on a 1 microvolt antenna signal ?

#### AlbertHall

Joined Jun 4, 2014
12,187

#### DickCappels

Joined Aug 21, 2008
9,508
Just to add to AalbertHall's explanation, the forward voltage specification applies to a specific current and temperature. This is true of all rectifier types as far as I know and can imagine.

#### crutschow

Joined Mar 14, 2008
31,111
A diode has an exponential relation between forward voltage and current, so will still conduct current at anything above zero volts.
The given "typical" forward voltages of diodes are usually at around a mA of so of current.

#### atferrari

Joined Jan 6, 2004
4,672
Most DMM, AFAIK, use 1mA for the diode test function.