VDI Notes on Diode Specifications

The VDI G and W Band Diode Products are abrupt junction diodes.  Typical forward current vs. voltage (IV) curves are shown on each specification for the customer's convenience.  The following are explanations of the parameters listed on the diode specifications with the exception of the W Band ZBD which has explanations listed on its specification:

  • Vf Forward Turn-on Voltage = Voltage measured at 1 µA forward current
  • ΔV = Voltage measured at 100 µA forward current minus Voltage measured at 10 µA forward current
  • Rs Series Resistance = ((Voltage measured at 10 mA - Voltage measured at 1 mA) - ΔV)/(10 mA - 1 mA) - Probe Resistance
  • Vr Reverse Breakdown = Voltage measured at 10 µA reverse current
  • Ct Total Capacitance = Total capacitance measured pad to pad
  • Cpp Pad to Pad Capacitance = Total capacitance measured pad to pad where the wiring/finger has been removed
  • Cfp Finger to Pad Capacitance = Capacitance measured finger to pad; estimated at approximately 1fF
  • Cj0 (the junction capacitance at zero volts) can be estimated as (Ct -Cpp)/N -Cfp where N is the number of anodes between the pads.

Agilent ADS, AWR Corp. MWO (Microwave Office), and Agilent Genesys models for the W Band Single Anode and W Band ZBD diodes can be accessed at the Modelithics, Inc. website.

Contact [email protected] with any additional questions.