set autoscale x
set autoscale y
set xrange [1:10000]
set yrange [-30:25]
set grid x y
unset key
set title ""
set xlabel 'Frequence (Hz)'
set ylabel 'Affaiblissement (dB)'

set sample 10000

m=0.05
f1=1000
f2=3000
f3=5000
f4=7000

T=4.5

plot (20*log((2*T*m*(x/f1))/(sqrt(((1-(x/f1)**2)**2)+((2*m*(x/f1))**2))))/(log(10))) title "fclk=100Khz", \
(20*log((2*T*m*(x/f2))/(sqrt(((1-(x/f2)**2)**2)+((2*m*(x/f2))**2))))/(log(10))) title "fclk=300Khz", \
(20*log((2*T*m*(x/f3))/(sqrt(((1-(x/f3)**2)**2)+((2*m*(x/f3))**2))))/(log(10))) title "fclk=500Khz", \
(20*log((2*T*m*(x/f4))/(sqrt(((1-(x/f4)**2)**2)+((2*m*(x/f4))**2))))/(log(10))) title "fclk=700Khz"

pause -1