AM noise impact on low level phase noise measurements.
The influence of the source AM noise in microwave residual phase noise experiments is investigated. The noise floor degradation problem, caused by the parasitic detection of this type of noise by an unperfectly balanced mixer, is solved thanks to a refinement of the quadrature condition. The parasitic noise contribution attributable to the AM to PM (phase modulation) conversion occurring in the device under test is minimized through the development of a dedicated microwave source featuring an AM noise level as low as -170 dBc/Hz at 10 kHz offset from a 3.5 GHz carrier.
Cibiel
Gilles
G
LAAS-CNRS and University Paul Sabatier, Toulouse, France. gcibiel@laas.fr
Régis
Myrianne
M
Tournier
Eric
E
Llopis
Oliver
O