Results for Balanced Mixer with Preamp

 

The data below summarizes results for the first balanced mixer-preamp measurements, measured from 3 Oct through 5 Oct 2001.

(A problem with Distiller is preventing storing all the data in a single pdf file.)

 

Category

Notes

Details

Link

Data vs. LO Frequency(1)

(1)

Receiver noise temp and

Mixer noise temp

BalMixerPreamp1.pdf

Data vs. IF Frequency

 

Receiver noise temp

Mixer noise temp

IF noise referred to Dewar Input

BalMixerPreamp2.pdf

Investigation of spike at 230 GHz

And LO Rejection

(2), (3)

Different LO triplers and

Normal reverse mixer bias, LO Rejection

BalMixerPreamp3.pdf

 

Notes

 

  1. Oscillation seen in bias voltages at 260 GHz removed by operating one mixer in open-loop mode. Crosstalk in bias between mixers observed.
  2. The first graph shows that the spike at 230 GHz at IF = 6.8 GHz remains even after changing LO triplers and LO levels.
  3. The reverse bias graph shows the receiver noise temperature improves at the same LO frequency as the noise spike, which suggests that the spike may result from a phasing problem between the mixers at this frequency.