Development of Wide Bandwidth Tunerless SIS Mixers
Radial Stub Probe on Silicon and Quartz substrates

Jacob Kooi, Frank Rice, Goutam Chattopadhyay, Stafford Withington, Jonas Zmuidzinas, and Tom Phillips

Last Updated Nov 21, 2002

Scale model measurements
E-plane probe on 25µm Silicon
E-plane probe on 50µm Quartz

Related Papers/Memo's:
 J.W. Kooi, G. Chattopadhyay, S. Withington, F. Rice, J. Zmuidzinas, C.K. Walker, and G. Yassin

IR & MM Waves, Vol. 24, No. 3, March 2003.

S. Withington, G. Yassin, J. Leech, and K.G. Isaak, B,
An Accurate Expression for the Input Impedance of One-Sided Microstrip Probes in Waveguide
Presented at 10th Space THz Symposium, Charlottesville, March 1999

Frank Rice

    E-field Movies:  
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  • We are currently in the process of developing tunerness SIS mixers in the range of:

  • 180-280 GHz,  (43% Instantaneous BW, 100 GHz Total RF BW)
  • 280-420 GHz,  (41% Instantaneous BW, 140 GHz Total RF BW)
  • 390-510 GHz,  (30% Instantaneous BW, 120 GHz Total RF BW)
  • 590-720 GHz,  (20% Instantaneous BW, 130 GHz Total RF BW)
  • 780-950 GHz,  (Please refer to the Twin-Slot Receiver Homepage)

    For the low frequency (230 GHz and 345 GHz) bands 25µm suspended Silicon or GaAs substrates can be used. In order to avoid subrate modes, the higher frequency bands require the silicon (GaAs) substrate to be thinned (==> membrane). If this is not practical suspended quartz substrates with lower dielectric constant may be used. In our designs we anticipate the use of 50 µm Quartz Substrates. The actual Probe impedance scales with the square root of the ratio of dielectric constants, i.e. 1.77. Though the actual probe impedance is very dependent on the actual RF Choke and WG geometery, the silicon Probe impedance locus is on the order of 28 Ω, and the Quartz probe impedance is ~ 45 Ω.
    All mixers will be implemented in FULL HEIGHT waveguide, which reduces Ohmic loss and eases manufacturablility.
     
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            Web Page created and last updated on Nov 23, 2002, by: Jacob W. Kooi