FYI -
There are some step recovery diode models and simulation schematics in our group's Files, from seven years ago.? I refer to these two directories, although beware that some of the uploaded files in them are inconsistent or missing things:
Files > z_yahoo > Files sorted by message number > msg_102029
/g/LTspice/files/z_yahoo/Files%20sorted%20by%20message%20number/msg_102029Files > z_yahoo > Files sorted by message number > msg_102029
/g/LTspice/files/z_yahoo/Files%20sorted%20by%20message%20number/msg_102890The .ZIP file in the second of these might be complete.? But it simulates VERY SLOWLY.? I do not know what its original uploader was attempting to do.? Simulating a 200 GHz oscillator for 0.55 seconds seems to me just a little bit odd, and the output file would be ginormous.? Attempting to run that simulation now, I see math errors - voltage values of -1.#IND, which is an error code from the Windows math library.? Some of the file descriptions suggest 400 MHz, but comments on the schematics say 200 GHz, so I would regard them with a great deal of skepticism.
But you can see the SPICE model they used for their step recovery diode.? If nothing else, it might be worth studying how it works.? Or maybe not.? Their models are Subcircuits, visible on the schematic sheets.
.SUBCKT SRD1A 1 2
+ Vp=25mV Ip=.220mA Vv=0.125 Iv=0.02mA Vpp=200mV ?C=0.6pF
.param Vt=boltz*(TEMP+273.15)/echarge
BTHE ?1 2 I = Ip*exp(-Vpp/Vt)*(exp(v(1,2)/vt)-1)
BTUN ?1 2 I = Ip*(v(1,2)/Vp)*exp(1-v(1,2)/Vp)
BEXC ?1 2 I = Iv*exp(v(1,2)-Vv)
C 1 2 {C}
.ENDS SRD1A
Andy
