DC biasing for microstrip circuit. Feedthrough capacitor?

Hi
I am designing a DC biasing circuit for my microstrip board. I was told that a feedthrough capacitor should be included as part of this bias circuit. Does anyone have information on this?

I am using ADS to simulate my circuit. Is feedthrough capacitor available in the software?

Thank you very much for any help rendered.

Kevin

would y please tell me your problems in detils,because the capacitor of the feedthrough line is common!

For Amplifier you can use λ/4 line with Radial Stub !

I was wondering what is the use of a feedthrough capacitor. I have included λ/4 radial stub as part of bias circuit. Is it still necessary to include a feedthrough capacitor?

It's always safe to use feedthrough capacitors for the DC supply lines entiring the microstrip box. Radial stubs may short 'hot' RF on the DC supply lines to ground, but does not prevent direct coupling from the microstrip circuit to the DC supply lines entering at the box wall. Using feedthrough capacitors, this coupling will be effectively decoupled to ground.

Hi,

feedtrough capacitors are mounted on the box walls and bias is fed trough it into the box. It is actually a low-pas filter, it has encapsulated inductor in series and shunt capacitor(s) to ground. It is used to prevent any possible undesirable signals not completely filtered within the box to propagate trough bias wires to the rest of the system. Being a low-pass in nature, it might not be able to eliminate low frequency signals, e.g. 50MHz or so, and it is desirable to have some large capacitance to ground inside the box (the best is a paralell combination in the range of 10uF, 100nf, 1nF)

flyhigh