Content
The parameter extraction for RF-diodes in the DC- and HF-domain requires various
model properties, which are exceeding the properties of simple standard diode
models. E.g. the influences of the package is represented with additional inductivities
and capacities in a macromodel (e.g. in a sub circuit).
A specific of PIN-diodes is the nonlinear dependency of the intrinsic area from the current (non-linearities of the transfer characteristic). The picture shows a BA597 inserted in switches and attenuators for frequencies above 10MHz. The DC-modeling is made with the Walston-models (compare / Walston, J.: Spice Circuits Yields Recipe For PIN Diodes, Microwaves&RF, November 1992,/) and provides only very small differences between model and measurement at all temperatures. In the following picture measurement and model results (dotted line) are compared at different temperatures (0, 25, 85 degC):
Picture 1: DC-modeling made with Walston model
The AC-modeling of these diodes is based on impulse measurements of the reverse recovery time (TRR) from which the model parameter TT is extracted, on S-parameter measurements and on CV-measurements. In the following pictures are results of S-parameter measurements and on CV-measurements compared with simulation results:
Picture 2: S11 as Imaginary- and Real-Part, reverse at 1V:
Picture 3: S11 as Imaginary- and Real-Part, forward at 10mA:
Picture 4: Comparison between model and measurement:
Offer for RF-Diodes: