Wide RF Bandwidth Radial Probe Waveguide Transition

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

Last Updated December 27, 2005

Scale Model Measurements

Electric Field Distribution

Rendering of Radial Probe Transition

    Performance Curves:

  • 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)

        E-field Movies:  

  • 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

    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 December 27, 2005, by: Jacob W. Kooi