Electronics Handbook/Devices/Filter/Band-pass

Band-pass Filter

A band-pass filter can be constructed from connecting a low-pass filter with a high-pass filter.

Network LR - CR Band-pass Filter

By connecting one low-pass filter LR with one high-pass filter CR a band-pass filter can be formed that can pass the frequency band from ${\omega }_1$ to ${\omega }_2$

Band Pass Range

${\omega }_1-{\omega }_2$

$\frac{R}{L}-\frac{1}{RC}$

Provide that

$\frac{1}{RC}>\frac{R}{L}$

$R<\sqrt{\frac{L}{C}}$

Net work RC - RLBand-pass Filter

By connecting one low pass filter RC with one high pass filter RL a band-pass filter can be formed that can pass the frequency band from ${\omega }_1$ to ${\omega }_2$

${\omega }_1-{\omega }_2$

$\frac{1}{RC}-\frac{R}{L}$

Provided that

$\frac{R}{L}>\frac{1}{RC}$

$R>\sqrt{\frac{L}{C}}$