**m Derived Band Pass Filter:**

We can obtain m Derived Band Pass Filter if the prototype band pass filter is simplified according to the network in the Fig. 9.35 which has been used to obtain m-derived low pass and high pass sections.

The T section in each case will have a shunt impedance, Z_{2}/m + (1-m^{2}/4m) Z_{1 }where Z_{1} and Z_{2} are the impedances of the prototype sections. We can get m-derived band pass section if we substitute values of Z_{1} and Z_{2} of prototype band pass filter section in equation,

The m Derived Band Pass Filter section is as shown in the Fig. 9.35.

If we substitute Z_{1} and Z_{2} in equation (1), we can get two values of frequencies. These frequencies are frequencies of infinite attenuation namely f_{1∞} and f_{2∞}. If the frequency of resonance is f_{0}, then the relationship between cut-off frequencies, and frequencies of infinite attenuation is given by,

Also we can write

Simplifying above equation,

**Variations of Characteristic Impedance (Z**_{0}) Attenuation Constant (α) and Phase Shift (β) with Frequency:

_{0}) Attenuation Constant (α) and Phase Shift (β) with Frequency:

The variations of characteristic impedance (Z_{0}), attenuation constant (α) and phase shift (β) with frequency are as shown in the Fig. 9.36 (a), (b) and (c).