Ok Jim. You're asked about the stray components hidden in the real
parts/circuit. If you take the values from the datasheets for die and/or
package or give it a guess if not available, and add values for the pcb
lines, you have a good simulation result. The pcb by itself is not of much
interest if you simulate not much over 100MegHz. Even starting a oscillator
with thermal noise is possible!
Sure, you must know what you're doing :-)

Spice by itself can simulate almost all if you have the right models
included - even if you wanna simulate a mechanical system. There is no
frequency limit at least to 100GHz.

Do you had bad result doing Spice?

To come back to your question: Spice will give you better results than your
real circuit! You can connect a probe with no interaction to the circuit!
Try this with your real parts! Don't forget the component variations in real
circuits coming from the manufacturing processes of the parts.

- Henry



"RST Engineering" schrieb im Newsbeitrag
...
Well, just for starters, what does Spice say about a 1000 pf capacitor
with
either ½" lead lengths or a total of 1" of PCB trace at 150 MHz.?

Jim




"John Larkin" wrote in
message
...
On Mon, 21 Nov 2005 16:40:40 -0800, "RST Engineering \(jw\)"
wrote:

You are going to use Spice to model an RF circuit. DId I get that
right?

Jim



Why not?

John