MILLIMETER WAVE
INSTRUMENTATION LAB


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Last Modified: Wednesday, 10-July-01 10:05 AM EDT




This material is based on work supported by the National Science Foundation under Grants AST-9532046 and AST-9725951.

Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect those of the National Science Foundation.

Pixel Detail

MMIC Preamplifiers
  • Input amplifiers use InP technology, designed at UMass, fabricated at TRW
  • Narrow band noise as low as 30K at 103GHz
  • Straight through design, 15mm long, using WR10 waveguide
Noise/gain plots amplifier
Noise/gain plots for each stage on left, MMIC detail on right


Isolators
  • Very compact isolator using Faraday rotation design
  • Much shorter ferrite (1.5mm long), higher magnetic field
  • Isolator operates well at low temperature. RT loss is 1.7 times larger than cold.
Isolator insertion loss Isolator
Graph of typical isolator insertion loss at 80K on left, isolator on right


Mixer / IF Amplifier
  • Subharmonic mixer uses beam-lead antiparallel-pair diodes (Cj(0) approx. = 40fF each). 2-20GHz MMIC amplifier included in block.
  • Mixer and amplifier are operated at 20K.
  • Very simple, compact circuit required for 5-20GHz IF band.
  • LO's at 40GHz and 60GHz, power 8mW. Matching circuit in waveguide.
  • Mixer operates single sideband through 80GHz high pass filter, and gain roll-off of preamplifiers above 115GHz.
Typical mixer performance Internal detail of mixer
Graph of typical mixer performance on left, internal detail of mixer on right


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