Problem on series feedback type DRO

[mehdi_hkh]

I'm designing a dielectric resonator oscillator in a series feedback configuration at 9.2GHz. I stimulated this circuit with ADS before it was actually built. I used spice model for ATF36077 transistor. The simulation included Harmonic Balance- Transient- large signal test and nyquist test. Coupling of dielectric resonator around to the microstrip line caused a “resonance frequency” at “9.2GHz”. Finally after simulating with ADS, I constructed the DRO circuit in order to observe its performance. The problem is that the measured data doesn’t agree with the simulation results. Simulation results confirm resonation only at exact 9.2GHz however; this circuit resonates at 4.65GHz, 9.31 GHz and 12.7GHz. Use of DR in circuit, just provides a slight shift in resonance frequency. I am confused and don’t understand what makes these differences between simulation and real results. I attach this DROs circuit hoping that you have time to examine it and answer to my problem.

 

[LeThalois]

hi mehdi_hkh i'm designing the same oscillator, but i can't
would you please send me the ADS file.
thank you a lot

 

[jsapkota]

Hi mehdi_hkh,
I am also designing the DRO. It would be helpful if you could provide me your ADS simulation files.
Thank you.