This presentation is the property of its rightful owner.
1 / 24

# E E 2415 PowerPoint PPT Presentation

E E 2415. Lecture 15 Introduction to Frequency Response, Poles & Zeroes, Resonant Circuit. Low-Pass Filter Example: (1/2). Low-pass Filter:. Low-Pass Filter Example: (2/2). Gain in Decibels. Using the Low-pass filter example:. Drops at 20 db per decade. Bode Plot of Low-Pass Filter.

E E 2415

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

## E E2415

Lecture 15

Introduction to Frequency Response, Poles & Zeroes, Resonant Circuit

Low-pass Filter:

### Gain in Decibels

Using the Low-pass filter example:

Drops at 20 db

### Definition: Poles & Zeroes

A zero at the origin

A pole at jw1

A zero at jw1

A pole at jw2

A pole at

the origin

### Effect of a Pole on the Bode Plot

• A pole causes the asymptotic slope to decrease by 20 db/decade.

• A pole at the origin causes the slope to start at –20 db/decade.

• A pole not at the origin causes a corner to appear at the pole’s frequency; then the slope is 20 db/decade less for frequencies greater than the pole’s frequency.

### Effect of a Zero on the Bode Plot

• A zero causes the asymptotic slope to increase by 20 db/decade.

• A zero at the origin causes the slope to start at +20 db/decade.

• A zero not at the origin causes a corner to appear at the pole’s frequency; then the slope is 20 db/decade more for frequencies greater than the zero’s frequency.

### Examples: (1/3)

A zero at the origin

A pole at jw1

A zero at jw1

A pole at jw2

A pole at

the origin

Zero at origin

Two poles

### Bandwidth of Resonant Bandpass (1/2)

at half power

Take square and

reciprocal of both sides

Need both solutions for

positive values of w

### Bandwidth of Resonant Bandpass (2/2)

Positive w for -1

Positive w for +1

Bandwidth for a series

resonant bandpass

filter