Exciter @ 10 Ghz for horn antenna

[atsou]

Hi,

Congratulations for this forum. It's really helpful. I am a new member and I have the following problem..
I want to construct an exciter @ 10 Ghz. I will use a gunn or an impatt diode but I dont really know how to make it. Does anybody has a clew about this? I think that I have to make a protection circuit but what else? How can this oscillate at 10 Ghz? with a cavity? how this cavity must be?

regards,

atsou

 

[divan]

gunn or impatt osc is difficult for homebrew , you have aplly to metallworks in case of waveguid base for one of this. for symplisity - diode must to be placed inside of resonant cavity and matched to provive a negative resistance more than positive resistanse of load. simplest way to make this osc is to plase diode in waveguid by special stand and place pair of screws in opposite sides from diode . one side of waveguide must be shortcircuited and another flange you have couple to load , horn at your case.
after that you trim screws for freq and power adjusting.

DC power line to gunn must be bypassed with 10uF at least , to avoid low freq parasitic oscillations, and supply for impatt must be a current source with voltage range about 100 v.

generally this is very easy , but much and much easy is to by this osc from one of manufacturers.
For 10GHz now to use GaAs microstrip MOSFET besed osc. is better than any from diodes if you are under 1 Watt.


regards.