0195136047.pdf

PROBLEMS 191

between signals, the tuning circuit response must
attenuate the signal of the second station (with a
frequency of 1020 kHz) by four times.
(a) Determine the values ofGandC.
(b) Find the bandwidth of the circuit.
3.4.16The twin-tee or notch network shown in Figure
P3.4.16 is often used to obtain band-reject charac-
teristics.
(a) Determine the transfer functionV 2 /I 1.
(b) Find the angular frequency at which the trans-
fer function will be zero.
*3.4.17Agyratoris sometimes used in integrated circuits
to simulate inductances. Consider the circuit of
Figure P3.4.17 consisting of a gyrator.
(a) Show that the impedance as seen to the right
at terminals 1–1′can be represented by an
inductor in series with a resistor.
(b) Determine the resonant frequency and band-
width for the following values:

R= 105 ;g= 10 −^3 S;C 1 =C 2 =100 pF.

3.4.18(a) Consider the capacitor-input filter circuit of

Figure P3.4.18 and obtain thez-parameters for

the circuit.

(b) Determine the transfer functionV 2 /V 1 when

I 2 is zero.

3.4.19The circuit shown in Figure P3.4.19 is the equiv-

alent circuit of a field-effect transistor (FET) am-

plifier stage.

(a) Determine they-parameters.

(b) For values ofμ=gm/gd >>1, obtain a

y-parameter equivalent circuit.

3.4.20For the circuit shown in Figure P3.4.20, obtain:

(a)z-andy-parameters;

(b) Transfer functionI 2 /I 1 whenV 2 =0.

3.4.21For the capacitor input filter circuit of Problem

3.4.18, determine theh-parameters.

2 R 2 R

+

1

V 1 R 2 Cs

I 1 I 2

1

Cs

1

Cs

−

+

V 2

−

Figure P3.4.16

vA

+

−

vB

+

1

1 ′

C 1 gvB gvA C 2 R

−

2

2 ′

Gyrator

Figure P3.4.17

V 1 V 2

R 1 Ls

I 1 I 2

R 2

+

−

+

−

1

Cs

Figure P3.4.18