An $N=3$ Chebyshev bandpass filter is to be designed with $3 d B$ passband ripple for a communication link. The center frequency is at $2.4 \mathrm{GHz}$ and filter has to meet bandwidth requirement of $20 \%$. The filter has to be inserted into $50 \Omega$ characteristic line impedance.

Solution:

center frequency of filter $=2.4 \mathrm{GH} 2$

Bandwidth requicement of filter $=20 \%$

$\%$ Bandwidth of filter $=\frac{\text { upper freq. limit - lower freq. limit }}{\text { center frequeacy }} \times 100$

$ \begin{aligned}\\ &\therefore \quad 20=\frac{\mathrm{Fu}-\mathrm{Fl}}{\mathrm{fc}} \times 100\\\\ &\therefore \frac{f_u-f_l}{f_c}=0.2\\\\ &\therefore \mathrm{fu}-\mathrm{fl}=0.2 \mathrm{fe}=0.2 \times 2.4 \mathrm{GH}=0.48 \mathrm{GH}_2\\\\ …