In a Wien bridge oscillator, it is found that at the frequency ωO there is no phase shift in RF/R gain loop and the phase shift of the amplifier is also zero. Then what is the equation for the radian frequency, given R1, C1 is the series network of bridge and R2, C2 is the parallel network?

• A. ωO=1/R1C1
• B. ωO=1/R2C2
• C. ωO=1/R1R2C1C2
• D. ωO=1/RFC1RC2