Определение
(C-V) и Y-параметров полевого
транзистора с управляющим p-n переходом при различных
условиях окружающей среды
С.М.Эл-Ханам
Университет Каира, Египет
Получена 17 июля 2009 г.
(C-V) and
Y-Parameters Determination of JFETs under Different Environmental Conditions
S. M. El-Ghanam
Women’s College
for Arts, Science, and Education,
Ain shams University, Heliopolis, Cairo Egypt
Received July 17, 2009
The C-V characteristics
of n-channel JFET have been measured as a function of temperature up to 140 0C
and γ- rays up to 100 kGy. The results show that the input capacitance Ciss
is an increasing function of temperature when measured at small bias voltage
and low frequency bands. On the other hand, Ciss was shown to
decrease from 11.68 down to 8.17 nF due to
γ- exposure up to 100 kGy. In addition, the physical parameters of the
gate-source junction were investigated, where their values were to shown to be
funcion of both temperature increasing and γ- exposure. The values of
the Y- parameters of common-source amplifier were calculated under influence of
temperature and γ- rays. The result shows that, the susceptance component
of the admittance increases due to temperature increasing, while decreasing
after γ- exposure. The investigation was extended to include the
temperature and radiation effects on the cutoff frequency fT0 . It
is clear from calculations that, as the temperature increases from 30 0C
up to 140 0C, fT0 dropped from 47 MHz down to 5 MHz, at
0.8 Volt. On the other hand its value was shown to increase from 43 MHz up to
102 MHz, at 0.8 Volt, due to γ- exposure up to 100 kGy.
Keywords:
JFET, input capacitance, Y-parameters, quality
factor, dissiption factor, phase
angle, impedance, cutoff frequency.