Help using OSCTEST and OSCAPROBE

[anisnn]

oscaprobe simulation

Hi all,

I am designing an oscillator using a MEMS resonator and the minicircuits MAR6 amplifier. I have done the simulations based on the steps shown in the link below:


I performed the open loop gain simulation and plotted the S21 transmission characteristics. I added a phase shifter to the circuit and tuned it so that it will have max gain at the zero phase shift point. Gain is approx 7 dB at this point.

I now run the same simulation using the OSCTEST2 at the open loop. But now I have -100 gain.. Can someone help me with this? Should I obtain the same results as the previous measurements?

I have uploaded the circuit just in case someone wants to look at it.

Thanks!
Anis

 

[Abhishekabs]

osciprobe

When you connect Osci test in your circuit that is at resonating port. you have to tune your circuit such that you will get s11>>1.
When you want to measure gain of the circuit that is s21 you should not connect oscitest in circuit. only do S parameter simulation & remove oscitest.
And for checking whether your circuit is oscillating at your desired frequency you have to use Osciprobe & do HB simulation.