Theoretical study of a Gunn diode in a resonant circuit

A computer simulation of a GaAs Gunn diode in a parallel resonant circuit has been made to determine the optimum device and circuit parameters. The maximum dc to RF efficiency, 5 to 8 percent, is obtained when the product of doping and length is between 10
¹²
and 2 × 10
¹²
cm
^-2
, the product of frequency and length is 10
⁷
cm/s, and the bias voltage divided by length is 8000 V/cm for a load resistance of
30 R_{0}
where R
0
is the low-voltage resistance of the diode. The product of output power and load resistance varies with frequency
f
as
C f^{2}
where
C
is 12,000 watt-ohm-GHz
²
for a load resistance of
50 R_{0}
. The frequency can be varied over an octave tuning range by the resonant circuit.