Spice3f5

Diode distortion

Intermodulation distortion of a diode and resistor.

A diode in series with a 1kΩ resistor, with a source that has both distortion inputs, DISTOF1 and DISTOF2. disto with a frequency ratio of 0.9 finds the intermodulation products at f1+f2, f1−f2 and 2f1−f2.

68.2n68.2n68.3n68.3n68.4n68.4n1k10k100k1M10M100Mfrequency (Hz)v(2)
f1+f2 product at v(2)
  • v(2)
70p75p80p85p1k10k100k1M10M100Mfrequency (Hz)v(2)
2f1-f2 product at v(2)
  • v(2)

The circuit: examples/diodisto.cir

	Diode-Resistor circuit
*
d1 1 2 diode
r1 2 0 1k
*
vcc 1 3 5v ac 0.001 sin(5 0.01 1000) distof1 0.01 distof2 0.01
vee 3 0 0
.model diode D is=1.0e-14 tt=0.1n cjo=2p
.control
disto dec 20 1.0e3 1.0e8 0.9
plot v(2)
.endc
.end

Run it with spice diodisto.cir, or open it with File › Load netlist in the Qt window. The plots and output above were made by util/mkexamples.py, which runs the deck in batch mode. All examples