Mixer IQ phase


    A complex (IQ) mixing step is used to move the signal from IF (100-400MHz) to baseband. Two mixers are used:
  1. 100-250 MHz with LO at 175 MHz
  2. 250-400 MHz with LO at 325 MHz
The lo's are programmable.
    IQ mixing needs the phase bewteen the I,Q output signal to be close to 90 degrees. If not, then unwanted images will appear in the opposite sideband.

    The phase of the IQ mixers was tested on 24oct07 and 25oct07. The setup was:
The plots show the results of the processing:
Hi band 240-325 (.ps) (.pdf):
Lo band 140-205 LO=205 and 215 (.ps) (.pdf):
processing: x101/071024/iqtestHi.pro iqtestLo.pro

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