Engineering topics

Honingh, C. E.

Publications and source records attributed to Honingh, C. E..

3 records

NASA NTRS1992

A low noise 410-495 heterodyne two tuner mixer, using submicron Nb/Al2O3/Nb tunneljunctions

A 410-495 GHz heterodyne receiver, with an array of two Nb/Al2O3/Nb tunneljunctions as mixing element is described. The noise temperature of this receiver is below 230 K (DSB) over the whole frequency range, and has lowest values of 160 K in the 435-460 GHz range. The calculated DSB mixergain over the whole frequency range varies from -11.9 plus or minus 0.6 dB to -12.6 plus or minus 0.6 dB and the mixer noise is 90 plus or minus 30 K.

Delange, G.↗

NASA NTRS1992

Comparison of measured and predicted performance of a SIS waveguide mixer at 345 GHz

The measured gain and noise of a SIS waveguide mixer at 345 GHz have been compared with theoretical values, calculated from the quantum mixer theory using a three port model. As a mixing element, we use a series array of two Nb-Al2O3-Nb SIS junctions. The area of each junction is 0.8 sq microns and the normal state resistance is 52 omega. The embedding impedance of the mixer has been determined from the pumped DC-IV curves of the junction and is compared to results from scale model measurements (105 x). Good agreement was obtained. The measured mixer gain, however, is a factor of 0.45 plus or minus 0.5 lower than the theoretical predicted gain. The measured mixer noise temperature is a factor of 4-5 higher than the calculated one. These discrepancies are independent on pump power and are valid for a broad range of tuning conditions.

Honingh, C. E.↗

NASA NTRS1992

Evaluation of integrated tuning elements with SIS devices

The resonance of integrated tuning stubs in combination with SIS detectors is measured and modeled. The predicted resonances are compared with measurements of stubs integrated with Nb/Al2O3/Nb junctions in a log-periodic antenna using a Michelson interferometer. Different stub lengths were made on different substrates (on 200 micron thick quartz and on a 7 micron thick silicon membrane) and the results show a fairly good agreement with the model calculations. Quartz substrates showed resonances up to 580 GHz, silicon membrane stub resonances reach as high as 480 GHz. An observed resonance at 560 GHz is probably a substrate effect from the membrane. The gap frequency for all the samples is 650 GHz and no resonances are detected above this frequency. Up to the maximum detected frequency dispersion is found to be negligible.

Dierichs, M. M. T. M.↗