Phase Noise Measurement
Phase noise
Crystal oscillator produces undesirable phase noise near the output frequency.
With recent advancement of wide band communications system requires, high phase noise performance of Crystal oscillators is more and more required.
Phase noise is measured in the frequency domain, and is expressed as a ratio of signal power to noise power measured in a 1 Hz bandwidth at a given offset from the desired signal.
In NAKA’s VCXO, best close-in noise results have been obtained using fundamental AT cut Crystals in the range of 12 to 33MHz.
Generally higher frequency crystals result in higher close-in noise because of their lower Q and wider bandwidths but NAKA’s VCXO realizes good close-in phase noise performance in VCXO even at 100-130MHz, by using multiplication technique.
E5052A
For the Phase noise measurements we have installed Agilent E5052A Signal Source Analyzer (SSA) in 2005, which greatly improved the phase noise measurement thru-put.
Phase noise data
| Phase noise data | 76.1111MHz SPXO |
|---|---|
| 122.880MHz VCXO |
|
| 120.000MHz VTCXO |
|
| 155.5200MHz VTCXO |
|
| 27MHz VCXO |
|
| 24MHzVCXO |
|
| 61.44MHzVCXO |
|
| 50.40MHz VCXO |