LAPLACE
TRANSFORMATION
AND ITS APPLICATION
ALIPURDUAR GOVERNMENT ENGINEERING
& MANAGEMENT COLLEGE
Name : Sarup Mukherjee
Department : Electronics & Communication Engineering
Subject : Network Theory
Subject Code : EC304
Roll No. :
Registration No. :
Topic : C1
Session : 2024-2025
Introduction to Laplace
Transform
Definition: The Laplace Transform is a mathematical
technique used to transform a function of time (t) into a
function of a complex variable (s).
AGENDA
∞ −𝑠𝑡
Formula: ℒ 𝑓 𝑡 = 0
𝑒 𝑓 𝑡 𝑑𝑡
Key Idea: Converts differential equations into algebraic
equations.
Properties of Laplace Transform
Linearity: ℒ 𝑎𝑓 𝑡 + 𝑏𝑔(𝑡) = 𝑎ℒ f t + bℒ 𝑔 𝑡
First Derivative: ℒ 𝑓′ 𝑡 = 𝑠ℒ f t − 𝑓(0)
Shifting: ℒ 𝑒 𝑎𝑡 𝑓(𝑡) = 𝐹(𝑠 − 𝑎)
Inverse Laplace Transform
DEFINITION: CONVERTS THE
LAPLACE DOMAIN FUNCTION
BACK TO THE TIME DOMAIN.
FORMULA: ℒ −𝟏 𝑭 𝒔 = 𝒇(𝒕)
𝟏
EXAMPLE: ℒ −𝟏 =𝒕
𝒔𝟐
Applications of Laplace Transform
1. Engineering:
• Electrical circuits (RLC analysis).
• Control systems (stability analysis).
2. Physics:
• Heat conduction problems.
• Vibrations and oscillations.
3. Mathematics:
• Solving differential equations.
Laplace Transform in Electronics
Engineering
1. CIRCUIT ANALYSIS
• SIMPLIFIES THE ANALYSIS OF RLC CIRCUITS BY CONVERTING DIFFERENTIAL EQUATIONS INTO
ALGEBRAIC EQUATIONS IN THE S-DOMAIN.
• EXAMPLE: 𝑉(𝑠) = 𝐼(𝑠)𝑍(𝑠), WHERE 𝑍(𝑠) REPRESENTS IMPEDANCE IN THE LAPLACE DOMAIN.
2. TRANSFER FUNCTIONS
• USED TO DERIVE THE RELATIONSHIP BETWEEN INPUT AND OUTPUT IN SYSTEMS.
𝑌(𝑠)
• EXAMPLE: 𝐻(𝑠) = 𝑋(𝑠) WHERE 𝐻(𝑠) IS THE SYSTEM'S TRANSFER FUNCTION.
3. FILTER DESIGN
• HELPS IN DESIGNING AND ANALYZING FILTERS (LOW-PASS, HIGH-PASS, BAND-PASS) USING POLE-ZERO
PLOTS.
• USED TO DETERMINE FREQUENCY RESPONSE.
4. SIGNAL PROCESSING
• USEFUL FOR ANALYZING AND PROCESSING SIGNALS (AMPLIFICATION, NOISE FILTERING).
• CONVERTS TIME-DOMAIN SIGNALS TO FREQUENCY-DOMAIN FOR EASIER MANIPULATION.
Advantages of Laplace Transform
• Simplifies complex differential
equations.
• Provides a unified approach for solving
linear systems.
• Useful in both theoretical and practical
problems.
Limitations
• Not suitable for nonlinear systems.
• Requires the function to be piecewise
continuous and of exponential order.
THANK
YOU