varactor diode for vco application !

[guymagled]

hi

im looking for the lowest Rs parameter varactor diode for a very low noise , wide band vco (2.5 - 3GHz).
the demands are for a :

1. 25v Br voltage diode
2. low Rs (high q) - around 0.4 ohm
3. low capacitance (from 5pf to 0.8pf Vs the Vt)
4. low cost

I saw the toshiba diodes and they look great ,but there
is no diode that meets my demands.
i also cheked the microsemi,infenion,sprague !

thanks

 

[nbucska]

try <

http://www.zetex.com>

or <

http://www.digikey.com>

<nbucska@pcperipherals DOT com> subj: eng-tips

 

[guymagled]

thanks for the information , but i allready checked these sites.
i just wondered whether someone used such a diode in the past and could spair some tips regarding the issue !?
or can recommand on a reliable company which has great
low Rs varactors .

BR
guy

 

[uWaveFDL]

Check out Panasonic MA27V11.
Available at DigiKey, PN MA27V11CT-ND. Cost: reasonable.
Data sheet available online at DigiKey.

 

[biff44]

The highest Q diodes are made with GaAs. A little hard to find now adays, but some are still out there.