want a superabrupt varactor operating at S band

[xiyx]

1pf varactor

The tune range has to include 0.7~9pF, and reverse tune voltage can be less than 30V. Can someone give me some manufacture information on this? Thx.

best rgs,
xiyx

 

[boy]

you might look at
**broken link removed**

 

[xiyx]

you might look at
h**p://www.skyworksinc.com/products_dynamic.asp?sid=1188&vtype=p

thx, boy,
but i think the tunable capacitance range is a little small. i need a big capacitance ratio and min. capacitance is below 1pf. can you give me some information about this?

regs,
xiyx

 

[boy]

I have never seen any varicap with capacitance < 1pf. You may need to dsesign an overtone oscilator so that you can use bigger varicap.

 

[xiyx]

I have never seen any varicap with capacitance < 1pf. You may need to dsesign an overtone oscilator so that you can use bigger varicap.

hi, boy,
can you give me something more detail about this? why will design an overtone oscilator? i cannot get it. thx. and i have found some varactors with capacitance < 1pf, e.g. bb833 fabricated by infineon.
best regs,
xiyx

 

[alex_vettoriale]

Hi,
if u visit the Infineon site:
https://www.infineon.com
u can find the right varicap for your application.
Varicap like BB831, BB833, BB837 and BB857
are used for SAT application, until 2.5GHz, with
your specifications about capacitance range and maximum voltage applicable....
The best for me are those with very low Ls (for
getting high parassite series resonance frequency)...
Ls=0.6nH is the almost best (SC79package)
regards,
alex_vettoriale

 

[xiyx]

Hi,
if u visit the Infineon site:
h**p://www.infineon.com
u can find the right varicap for your application.
Varicap like BB831, BB833, BB837 and BB857
are used for SAT application, until 2.5GHz, with
your specifications about capacitance range and maximum voltage applicable....
The best for me are those with very low Ls (for
getting high parassite series resonance frequency)...
Ls=0.6nH is the almost best (SC79package)
regards,
alex_vettoriale

thx, alex,
but now i have used the bb833, but from the datasheet i found this element only can be used up to 2.5ghz. now i need it to work steadily up to 4ghz at least. have you used it in this freq. band? looking forward to your reply.

best rgs,
xiyx