Question:

(a) A typical RF filter is made up of sections using circuit components. One example of a section is the Inductor-Capacitor (L-C) section. State two other types of RF sections.

(b) A typical filter is designed using n L-C sections. A certain load impedance Zo is connected in parrallel to the last section. For a matched network, calculate Zo in terms of the other circuit parameters.

(c) Using the same circuit in 2(b),

(i) Derive the constant k, the ratio of the voltage level at (n+1)^th to that at the n^th section in terms of L and C components and angular frequency (w).

(ii) Prove that the voltage V_n+1 = ??ⁿVs, where Vs is the source voltage.

(d) Hence, sketch the graph of k with respect to the angular frequency. Discuss what happen when the above filter is used at low frequencies and explain what happen as the frequency increases.