microwave oscillator designing

[fahsa]

anyone give me the steps involved in designing a microwave oscillator.

 

[BigBoss]

You talk about veeerrryy wide subject. "Microwave oscillators!!!"

Which frequency you'll use ? Which topology wil be useful for you ? It will be in a IC or on a PCB ? etc etc..
There is no "rule of thumb" or " to do list" for the oscillators.

Oscillators are designed by considering

-Frequency of Interest
-Topology ( BJT,FET,SAW,VCO,OSC+PLL,DRO,Cavity,etc etc..)
-Output level
-Cost
-Phase Noise
-Pulling
-Pushing
-Drifting
-Offset

etc etc..

I suppose you that first read a good Book about oscillators like

I.Bahl , P.Bhartia," Microwave Solid State Circuit Design" J.Wiley

Vendelin G. " Microwave Circuit design by Linear and Nonlinear Techniques"

or the one what you can find..

Good Luck

 

[fahsa]

I have the basic understanding of microwave oscillators. I just want to know the common design procedures whether on PCB, microstrip or MMIC. Also what are differences or advantages/disadvantages in design issues such as

-feed back or negative resistance
-PCB,MMIC or microstrip
-lumped or distributed design

suppose that the oscillator is transistor based of frequency 5GHZ.

 

[flatulent]

two factors

There are three factors (among many) to consider.

1. The amplitude limiting method should not be a nonlinearity across the resonant circuit. The ideal case is a two or more stage amplifier where the limiting is in the second stage or by an AGC type circuit. This keeps the Q of the resonator high. Phase noise is related to the inverse of resonator Q squared.

2. The resonator should be operated at the frequency where the phase changes the most rapidly with frequency. This means that the phase shift of the rest of the loop has to be done properly.

3. Generally, distributed resonator elements have higher Q than lumped ones at these frequencies. Three dimensional resonators are better than two dimensional ones (cavity better than transmission line)