AnsweredAssumed Answered

Frequency down-conversion not visible

Question asked by ronan on Nov 17, 2010
Latest reply on Nov 29, 2010 by Dr_joel
Hi !
I am currently trying to measure the gain and phase of the front-end part of a GPS signal recording system.
The front-end role is to amplify the input signal and to down-convert it from 1575.42 MHz to 131.25 MHz.

I don't know why a peak at 131.25 MHz does not appear when the input signal covers a band like [0-2 GHz] ... It seems that just the noise is present.

I have done a full 2-port calibration before measuring the system. I tried to increase the sweep time, to do some averaging/smoothing, but nothing better happens.

Could you help me ??

(I am using a HP Agilent 8573D Network Analyzer with N-type standards, and some SMA cables)

I thank you in advance !!