which part number would you recommend for the lowest phase noise crystal oscillator design? The transistor should have very low 1/f noise (datasheets don't provide this data). Some designs prefer NEC CEL's NE688xx family for the low 1/f.
The oscillator will use either 3rd or 5th overtone at approx. 100-200MHz. Would 5th overtone crystal produce better or worse phase noise performance - why?
The Infineon's app note suggests that the best oscillator transistor is a device with the lowest possible fT. A commonly used criteria is: fT ≤ 2 x fosz. What is the reason that the lower fT would give better phase noise?
N1UL said:For low noise crystal oscillators , depending on the frequency, a FET or a BIP transistor with the right size, fT and proper bias condition should be selected. More information about flicker noise feeback will be found in
Ulrich L. Rohde, Ajay K. Poddar, Georg Böck "The Design of Modern Microwave Oscillators for Wireless Applications ", John Wiley & Sons, New York, NY,
Ulrich
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?