Quonset Microwave
www.quonsetmicrowave.com
QM2010-10-20
USB RF Synthesizer Module
10 GHz
– 20 GHz output
For price, delivery, and to place orders, please contact Quonset Microwave, a subsidiary of Applied Radar:
315 Commerce Park Road, North Kingstown, RI 02852 Phone: 401-295-0062
-4-
Revised June 21, 2023
Frequency Reference Considerations
Aside from reference divider selection, the phase noise performance and stability of the reference oscillator
has a direct effect on QM2010 phase noise performance. The QM2010-10-20 includes an on board, high
precision TXCO 50 MHz reference whose phase noise parameters are outlined in Table 2. To ensure optimal
QM2010 performance when an external reference is required, it is important to choose an accurate and stable
oscillator with specifications equal to or better than the 50 MHz TCXO Int Ref outlined in Table 2.
Figure 3 depicts phase noise performance differences between the QM2010-10-20 high precision TXCO
internal reference and an ultra high precision OCXO external reference. Phase noise performance with
different reference divider settings is also shown. Table 2 outlines the performance differences between
reference oscillators.
Table 2
–
Reference Characteristics
– Internal Reference vs. External
Parameter
50 MHz TCXO Int Ref
20 MHz OCXO Ext Ref
SSB Phase Noise at 10 Hz Offset
-70 dBc/Hz
-110 dBc/Hz
SSB Phase Noise at 100 Hz Offset
-110 dBc/Hz
-135 dBc/Hz
SSB Phase Noise at 1 kHz Offset
-135 dBc/Hz
-150 dBc/Hz
Frequency Stability at 25
o
C
± 0.5 ppm
± 0.2 ppm
Frequency Stability vs. Temp
± 0.25 ppm
± .02 ppm
Figure 3 -
Phase Noise Reference and Reference Divider Comparison
