can I use ordinary SMD capacitors capacitor at 10 GHz

Hi
I am working on a trancieveroperating at 10 GHz.. I need to use capacitors for decoupling RF from power supply and also for DC blocking..

can I use the commony available SMD capacitors for the purpose.. or do I have to use some special type of capacitor.

Hi,

Nope, you can't, there are specially designed caps for microwave.
search the net for some info for such components.

No No No :)

I think u can use ATC 600 series Ultra low ESR High Q Microwave Capacitor.


Regards
Asim Ali

Why not? Of cource, the value range is below 1...0.5pF. But at 10GHz you do not need more. Just for reference look at the site h**p://www.dilabs.com/products/products.aspx?catid=8
Rgds

Some "standard" caps work fine up at 10 GHz, some have series resonant issues. What you really have to stay away from are the ultrahigh K materials that they use to make the larger capacitance values very small physically--you can end up with a rectangular resonator instead of a capacitor! But a 100 pF 0402 should be fine.

Hi, Normal SMD capacitors like the 0603 can't be used at 10 GHz, even the 0402 do not go that high. The problem is that the capacity written on the caps will increase (yes, increase) at higher frequencies and also internal resistance/inductance will increase. If you need it to feed the antenna signal at 50 Ohm to a matching network you can use it (if your lucky) but all other work is not going to work.

Normal SMD C's will work fine upto some 1500 MHz, above this frequency performance drops. better use ATC 600 series of capacitors designed for 10GHz and beyond.

Better use a radial stub to decoupling RF from powerlines.

regards,

Paul.

PS: Before you try, do not use normal FR4 at 10 GHz !..

Does this ATC 600 series belongs to a particular manufacturer or thats the general name for microwave grade components..

plz provide some material on commonly used high frequency resisters and capacitors

Hi, Check http://www.atceramics.com/. Panasonic and Vishay also have some cap's that are very good !. You can get them through Farnell, DigiKey.

Paul.