# Electronics Fundamentals/Electronic Filter/High Pass Filter

## CR High Pass Filter

### Characteristics

${\displaystyle {\frac {V_{o}}{V_{i}}}={\frac {R}{R+{\frac {1}{j\omega C}}}}={\frac {j\omega T}{1+j\omega T}}}$
${\displaystyle T=RC}$
${\displaystyle \omega _{o}={\frac {1}{T}}={\frac {1}{RC}}}$

## RL High Pass Filter

### Characteristics

${\displaystyle {\frac {V_{o}}{V_{i}}}={\frac {R}{R+{\frac {1}{j\omega C}}}}={\frac {j\omega T}{1+j\omega T}}}$
${\displaystyle T={\frac {L}{R}}}$
${\displaystyle \omega _{o}={\frac {1}{T}}={\frac {1}{RC}}}$

## Summary

High Pass Filter has stable voltage which does not change with frequency over a range of high frequency . High Pass Filter can be constructed from CR or RL network