# Quartz crystal oscillator problem

1. Nov 23, 2006

### harzo

Hello

I am having difficulty with an assignment problem I have been set. It is an exercise based in Excel. Here is the problem I was given:

For typical values R = 35 Ohms, L = 150 mH , Cs = 10 fF and Cp = 15pf, evaluate the expression for the impedance (equation (B4)) as a function of frequency in the range .
Then use equation (1) with Rd = 10 kOhms to evaluate (Vo/Vi) in another column on the same spreadsheet (just assume Vi = 1 V).
Plot a graph of (Vo/Vi) vs. frequency (again on the same spreadsheet) and ensure that you can see a resonant feature in it. The resonant feature is actually a double-feature, a dip followed immediately by a peak. This double-feature is very sharp, so make sure you use a fine enough frequency interval to observe it. If you do not observe it, check your input values and your calculation.

The equations referenced in the problem can be found here:

My main problem is that when I draw my graph I am not getting the double feature mentioned in the problem.

Here is my work so far:

And here is the worksheet with equations on display:

Here is my graph:

Any ideas would be greatly appreciated, I understand this is a rather large demand. I've been stuck on this for days and my head is now fried.
Thanks.

Last edited: Nov 23, 2006
2. Nov 24, 2006

### harzo

I managed to get the problem resolved! Thanks anyway =)