RC Phase shift oscillator

Thread Starter

Binus01

Joined Jul 12, 2022
3
Hi team,
I am looking for help design an RC phase shift oscillator with a frequency of 400MHz. The simulation on proteus is not showing any waveform. I would appreciate if anyone could assist .Thanks
 

LvW

Joined Jun 13, 2013
1,484
Disregarding the mentioned frequency of 400MHz - you should re-check the shown circuit (in particular the function of resistor R1).
More than that - what is the purpose of the shown input signal source?
 

Ian0

Joined Aug 7, 2020
5,899
Hi team,
I am looking for help design an RC phase shift oscillator with a frequency of 400MHz. The simulation on proteus is not showing any waveform. I would appreciate if anyone could assist .Thanks
400MHz is optimistic for an LM358.
Component values suggest about 15kHz.
 

Ian0

Joined Aug 7, 2020
5,899
What size of the op amp would do
Generally, op-amps don’t do 400MHz.

For a phase shift oscillator to work, the amplifier must have gain of at least 20dB at the oscillator frequency, and very little phase shift of its own. So you need something with a gain-bandwidth product of >10GHz.
Good luck.

You should also learn how to calculate the component values, as you are out by more than four orders of magnitude.
https://en.wikipedia.org/wiki/Phase-shift_oscillator
 

Ian0

Joined Aug 7, 2020
5,899
At that frequency a Colpitts or Hartley oscillator design may be more appropriate.
At that frequency, any other oscillator would be more appropriate, except, perhaps, a 555.
At the nearby 418MHz popular remote control frequency, SAW (surface acoustic wave) oscillators are popular.
 
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