Hardware Reference
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R
1
C
1
x
CCII+
V
0
z
R
4
C
2
y
Y
in
R
3
R
2
Fig. 7.2 A canonic active-RC circuit capable of realizing an ideal FDNR, a lossy FDNR, parallel
tuned circuit and an oscilltor proposed by Soliman [
4
]
If the component values are selected such that R
1
¼
R
3
,R
2
¼
2R
1
,R
1
>
R
4
and
C
2
¼
(3/2)C
1
, then
s
1
3
1
1
R
1
R
4
f
0
¼
ð
7
:
6
Þ
ˀ
C
1
R
1
2
Thus, it is seen that f
o
can be controlled by a single grounded resistance R
4
and can
also be controlled by external voltage by replacing this resistor by an FET working
in the triode region, however, the circuit lacks the provisions of providing inde-
pendent control of CO through a single variable resistance.
Another single-CC SRCO which does not have the above mentioned limitation
was proposed by Senani in [
5
]. This circuit employs one more resistor than
Soliman
'
s circuit and is shown here as Fig.
7.3
. Subject to the fulfillment of the
condition
C
1
C
2
¼
1
þ
1
R
1
þ
1
R
2
R
3
ð
7
:
7
Þ
the characterizations of this circuit are:
CO
R
4
¼
R
2
ð
7
:
8
Þ
:
1
=
2
R
2
2
C
1
C
2
R
1
R
3
R
0
FO
:
ω
0
¼
ð
7
:
9
Þ
It is, thus, seen that in this circuit, CO can be satisfied by adjusting the grounded
resistor R
4
without effecting FO which is also independently controllable by
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