Message	Date	From	Subject
4303	2010-02-20 08:43:27	Brooke Clarke	Understanding Mixer Diodes
Hi Joe: Schottky diodes can be made using different substrate materials and different metals resulting in different performance in mixers. An easy test for barrier height is to use the diode function (Vf @ 1 ma) on a DMM like the Fluke 87 or similar, see: http://www.prc68.com/I/DMM.shtml The lower the Vf @ 1 ma the lower the LO power needed for the mixer. A more complex parameter is related to what's called space charge current limiting and for that see: Understanding Diodes & RF/Microwave Operation and points out that the WJ app notes on mixers did not understand this. http://www.prc68.com/I/Diodes.html -- Have Fun, Brooke Clarke, N6GCE http://www.PRC68.com

Hi Joe:

Schottky diodes can be made using different substrate materials and
different metals resulting in different performance in mixers. An easy
test for barrier height is to use the diode function (Vf @ 1 ma) on a
DMM like the Fluke 87 or similar, see: http://www.prc68.com/I/DMM.shtml

The lower the Vf @ 1 ma the lower the LO power needed for the mixer.

A more complex parameter is related to what's called space charge
current limiting and for that see:
Understanding Diodes & RF/Microwave Operation and points out that the WJ
app notes on mixers did not understand this.
http://www.prc68.com/I/Diodes.html

--
Have Fun,

Brooke Clarke, N6GCE
http://www.PRC68.com